© Copyright 2003 Opera Software.
This specification defines Web Forms 2.0, an extension to the forms features found in HTML 4.01's forms chapter. Web Forms 2.0 applies to both HTML and XHTML user agents, and provides new strongly-typed input fields, new attributes for defining constraints, a repeating model for declarative repeating of form sections, new DOM interfaces, new DOM events for validation and dependency tracking, and XML submission and initialization of forms. This specification also standardises and codifies existing practice in areas that have not been previously documented.
HTML4, XHTML1.1 and the DOM are thus extended in a manner which has a clear migration path from existing HTML forms, leveraging the knowledge authors have built up with their experience with HTML so far.
This is a work in progress! This document is changing on a daily if not hourly basis in response to comments and as a general part of its development process. Comments are very welcome, please send them to htmlforms@damowmow.com and cc www-archive@w3.org. Thank you.
It is very wrong to cite this as anything other than a work in progress. Do not implement this in a production product. It is not ready yet! At all!
This document currently has no official standing within the W3C at all. It is the result of loose collaboration between interested parties over dinner, in various mailing lists, on IRC, and in private e-mail. To become involved in the development of this document, please send comments to the address given above. Your input will be taken into consideration.
This is a working draft and may therefore be updated, replaced or rendered obsolete by other documents at any time. It is inappropriate to use Working Drafts as reference material or to cite them as other than "work in progress".
This draft contains a couple of namespaces that use the
data: URI scheme. These are temporary and will be changed
before this specification is ready to be implemented.
To find the latest version of this working draft, please follow the "Latest version" link above.
input element
output element
textarea element
form element
pattern attribute
required attribute
form attribute
autocomplete attribute
inputmode attribute
help attribute
This is an update to the forms features found in HTML 4.01's forms chapter, which are informally referred to as Web Forms 1.0.
Authors have long requested changes to HTML4 to support some of their more common needs. For example, take this extract from a recent post written by an anonymous poster on the popular topic-driven Slashdot forum:
There are three things that need adjustments to get decent forms in HTML.
First, have the option of not redrawing the page upon submission. [...] Second, have a "grid" widget that allows spreadsheet-like data entry grids.
Third, have validation options such as <input type="text" name="foo" format="number" decimals=2> or perhaps <input type="number" name="foo" decimals=2>
This post is typical of the kind of comments made by Web authors. Requirements from such comments in mailing lists and other discussions have been examined and from these sources a set of requirements and design goals were derived:
Not all the desired features have been included in this specification. Future versions may be introduced to address further neads.
This specification does not describe the complete behaviour of an HTML or XHTML user agent. Readers are expected to refer to the existing specifications for the definitions of features that this specification does not change.
This specification clarifies and extends the semantics put forth in [HTML4] for form controls and form submission. It is expected to be implemented in ordinary HTML user agents alongside existing forms technology, and indeed, some of the features described in this draft have been implemented by user agents as ad-hoc, non-standard extensions for many years due to strong market need.
This specification can also be viewed as an extension to [XHTML1]. In particular, some of the features added in this module only apply to XHTML documents, for example features allowing mixed namespaces.
This specification is in no way aimed at replacing XForms 1.0 [XForms], nor is it a subset of XForms 1.0.
XForms 1.0 is well suited for describing business logic and data constraints. Unfortunately, due to its requirements on technologies not widely supported by Web browsers, it has not been widely implemented by those browsers itself. This specification aims to simplify the task of transforming XForms 1.0 systems into documents that can be rendered on every day Web browsers.
In this transformation model, the XForms processor is a server-side process that converts XForms and XML Schema documents, according to the XForms specification, into HTML and Web Forms documents, which are then processed by the client side Web Forms processor, along with a style sheet for presentation.
The structured XML instance data stored on the server-side (e.g. in a database) is converted by the XForms processor into name/value pairs that are then used by the UA to prefill the form. Submission follows the opposite path, with the UA generating name/value pairs and sending them to the XForms processor on the server, which converts them back into structured XML for storage or further processing.
In order to simplify this transformation process, this specification attempts to add some of the functionality of XForms with a minimum impact on the existing, widely implemented forms model. Where appropriate, backwards compatibility, ease of authoring, and ease of implementation have been given priority over theoretical purity.
The following features of XForms have not been addressed:
The majority of the features that XForms supports using declarative syntax are, in this specification, handled by using scripting. Some new interfaces are introduced to simplify some of the more tedious tasks.
This specification is unrelated to the XForms Basic profile.
A previous version of this draft was called "XForms Basic". This name has been changed so as to avoid confusion with the similarly named draft from the W3C.
This draft does not address all needs. In addition to the features of XForms that have not been addressed (see above), the following features were considered but rejected for this version of the specification:
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].
Diagrams, examples, and notes are non-normative. All other content in this specification is intended to be normative.
This specification includes by reference the form-related parts of the HTML4, XHTML1.1, DOM2 HTML, DOM3 Core, and DOM3 Events specifications ([HTML4], [XHTML1], [DOM2HTML], [DOM3CORE], [DOM3EVENTS]). Compliant UAs must implement all the semantics of those specifications to claim compliance to this one.
Documents that use the new features described in this specification
using HTML over HTTP must be served as text/html.
Documents that use the new features described in this specification
using XHTML or other XML languages over HTTP must be served using an XML
MIME type such as application/xml or
application/xhtml+xml. [RFC3023]
This specification introduces attributes for setting the maximum size or range of certain values. While user agents should support all possible values, there may be implementation specific limits.
This specification refers to both HTML and XML attributes and DOM attributes, often in the same context. When it is not clear which is being referred to, they are referred to as content attributes for HTML and XML attributes, and DOM attributes for those from the DOM. Similarly, the term "properties" is used for both ECMAScript object properties and CSS properties. When these are ambiguous they are simply qualified as object properties and CSS properties respectively.
Generally, when the specification states that a feature applies to HTML or XHTML, it also includes the other. When a feature specifically only applies to one of the two languages, it is called out explicitly, as in:
...it is possible that authors would prefer to declare the page's forms in advance, in the
headelement of XHTML documents (this does not apply to HTML documents).
Unless otherwise stated, XML elements defined in this specification are
elements in the http://www.w3.org/1999/xhtml/ namespace, and
attributes defined in this specification have no namespace. This does not
apply to HTML as HTML does not support namespaces.
HTML input elements use the type attribute to
specify the data type. In [HTML4], the types (as
seen by the server) are as follows:
text
password
checkbox
radio
submit
file
image
hidden
In addition, HTML also provides a few alternate elements that convey typing semantics similar to the above types, but use different content models:
select
select multiple
checkbox type, whose values are
structurally kept together.
textarea
button
submit type but with a richer content model.
There are also two button types (available on both input
and button elements) that are never submitted:
button and reset.
This specification includes all of these types, their semantics, and their processing rules, by reference, for backwards compatibility. Compliant UAs must follow all the guidelines given in the HTML4 specification except those modified by this specification.
These types are useful, but limited. This section expands the list to cover more specific data types, and introduces attributes that are designed to constrain data entry or other aspects of the UA's behaviour.
In addition to the attributes described below, some
changes are made to the content model of HTML form elements to take into
account scripting needs. Specifically, the form, legend, select, and
optgroup elements may now be empty (in HTML4, those elements
always required at least one element child, or, in the case of
legend, at least one character of text). The
optgroup element may now be nested, as suggested by the HTML4
specification.
Also, as controls no longer need to be
contained within their form element to be associated with
it, it is possible that authors would prefer to declare the page's forms
in advance, in the head element of XHTML documents (this does
not apply to HTML documents). This is therefore allowed, although only
when the form element is empty.
Similarly, form elements in XHTML may now be nested (this
does not apply to HTML). Form controls by default associate with their
nearest form ancestor. Forms are not related to ancestor forms in any way
semantically, and do not share attributes or form controls or events
(except insofar as events bubble up the DOM).
The form and select elements are extended with
data attributes for fetching values
and options from external resources.
input elementSeveral new types are introduced for the type attribute. As
with the older types, UAs are recommended to show specialized widgets for
these types, instead of requiring that the user enter the data into a text
field.
The formats described below are those that UAs must use when submitting the data. They do not necessarily represent what the user is expected to type. It is the UA's responsibility to convert the user's input into the specified format.
datetime
This specification does not specify how the widget should
appear. It could be something like this:
UAs may display the time in whatever time zone is appropriate for the user, but should be clear to the user that the time is globally defined, not time-zone dependent. The submitted date and time must be in the UTC timezone.
date
expdate
week
time
number
A number. The allowed precision of the number decides what UI user
agents may show, and is dicussed below, under the precision attribute.
Numbers must be submitted as follows: an optional minus sign ("-"), one or more decimal integers, optionally a decimal point (".") and a decimal fractional part, together forming a number representing the base, followed optionally by the lowercase literal letter "e", another optional minus sign, and a decimal integer exponent representing the index of a power of ten with which to multiply the base to get the resulting number. If the exponent part is omitted it must be assumed to be zero.
For example, negative-root-two, to 32 significant figures, would be -1.4142135623730950488016887242097e0, the radius of the earth given in furlongs would be 3.17053408e4, and the answer to the life, the universe and everything could be any of (amongst others) 42, 0042.000, 42e0, 4.2e1, or 420e-1.
This format is designed to be compatible with scanf(3)'s
%f format, ECMAScript's parseFloat, and
similar parsers while being easier to parse than required by some other
floating point syntaxes.
Note that +0, 0e+0, +0e0 are
invalid numbers (the minus sign cannot be replaced by a plus sign for
positive numbers, it must simply be dropped). UAs must not submit
numbers in invalid formats.
The submission format is not intended to be the format seen and used by users. UAs may use whatever format and UI is appropriate for user interaction; the description above is simply the submission format.
email
addr-spec token, defined in RFC2822 section 3.4.1,
excluding the CFWS subtoken everywhere and the
FWS subtoken everywhere except in the
quoted-string subtoken). UAs could, for example, offer
e-mail addresses from the user's address book.
tel
global-phone-number token, defined in RFC2806 section
2.2).
uri
absoluteURI token, defined in RFC2396 section 3). UAs could,
for example, offer the user URIs from his bookmarks.
location
Servers should ignore data following a second comma (in other words, the data is really a comma separated list, and currently only the first two fields are defined). This will allow for future extension of this field. Clients should only specify coordinates that are accurate to at least a few hundred meters. User agents may offer "bookmarked" locations for the user's convenience, or offer a map-based control for coordinate selection, or offer the current location as determined by GPS, or use other interfaces. User agents should not automatically send the user's location without the user's consent.
For example, the value 37.386013,-122.082932 is a coordinate near Santa Cruz, in California, USA.
Empty fields (those with no value) do not need to match their type. (Although if they are required fields, they will stop submission for that reason anyway.)
On the other hand, fields that are not successful (such as disabled controls) do not take part in submission, and therefore are simply not checked for validity.
The following form uses some of the types described above:
<form action="..." method="post" onsubmit="verify(event)">
<p>
<label>
Quantity:
<input name="count" type="number" min="0" max="99" value="1" />
</label>
</p>
<p>
<label for="time1"> Preferred delivery time: </label>
<input id="time1" name="time1" type="time" min="08:00:00" max="17:00:00" value="08:00:00" /> —
<input id="time2" name="time2" type="time" min="08:00:00" max="17:00:00" value="17:00:00" />
</p>
<script type="text/javascript">
function verify(event) {
// check that time1 is smaller than time2, otherwise, swap them
if (event.target.time1.value >= event.target.time2.value) { // ISO8601 times are string-comparison safe.
var time2Value = event.target.time2.value;
event.target.time2.value = event.target.time1.value;
event.target.time1.value = time2Value;
}
}
</script>
</form>
Servers should still perform type checking on submitted data, as malicious users or rogue user agents might submit data intended to bypass this client-side type checking. Validation done via script may also be easily bypassed if the user has disabled scripting.
The size attribute of the input element is
deprecated in favor of using CSS to specify the layout of the form.
To limit the range of values allowed by the above types, two new attributes are introduced, which apply to the date-related, time-related, numeric, and file upload types:
min
max
For date, time and numeric fields, the values indicate the allowed range. For file upload fields, the values indicate the allowed number of files.
The ERROR_TYPE_MISMATCH code is used for fields whose values do not match their types, and the ERROR_RANGE_UNDERFLOW and ERROR_RANGE_OVERFLOW codes are used for fields whose values are outside the allowed range.
A field with a max less than its
min can never be satisfied and thus would
block a form from being submitted. This is not not make the document
non-conformant.
An extra attribute is also introduced to control the precision for the
number type:
ndp
min and max of
course).
These numbers have precisions of no more than 2dp: 0, 1, 1.23, 0.123e1, 123e-1, 123456789.010
These numbers have precisions of more than 2dp: 0.001, 1.234, 0.1234e1, 123e-3, 123456789.001
nsf
min and max of
course).
These numbers have precisions of no more than 2sf: 0, 1, 1.20, 0.120e1, 120e-1, 120000000.000
These numbers have precisions of more than 2sf: 0.00123, 123, 1.23, 0.123e1, 123e-1, 123000000.000
integer
0dp. If the field doesn't match
any of the other values, it should be treated as this value.
float
rough integer or just rough
min and max attributes, visual UAs may use a track bar
control. The value should be an integer (same as 0dp).
The ERROR_PRECISION_EXCEEDED
code is used for fields whose numbers have more precision than allowed by
the precision attribute. However,
UAs may silently round the number to the maximum precision instead of
reporting a validation error.
User agents are recommended to never convert user- and author-supplied values to their binary numeric representation, keeping the values in string form at all times and performing comparisons in that form. This ensures that UAs are able to handle arbitrarily large numbers without risking data loss due to rounding in the decimal-to-binary conversion.
If a UA needs to round a number to its nearest binary equivalent, for example when converting a user-supplied decimal number and an author-supplied minimum in order to compare them to establish validity (ignoring the suggestion above to do these comparisons in string form), algorithms equivalent to those specified in ECMA262 sections 9.3.1 ("ToNumber Applied to the String Type") and 8.5 ("The Number type") should be used (possibly after suitably altering the algorithms to handle numbers of the range that the UA can support). [ECMA262]
output elementThe output element acts very much like a span
element, except that it is considered to be a form control for the
purposes of the DOM. Its namespace is the same as for the other form
control elements, http://www.w3.org/1999/xhtml. It has no
attributes beyond the common attributes and the form
attribute. Its value is given by its contents, which must be only text
(like the textarea element). Its value can be set dynamically
via the value DOM attribute, thus replacing the contents of
the element.
The initial value of the output control is stored
in a mutable defaultValue DOM attribute of type
DOMString. This is similar to the way textarea
elements work, except that the contents of an element for
output controls reflects the current value not the
initial, or default, value. See [HTML4] section
17.2 for the
definiton of the term "initial value".
The output element is never successful for form submission. Resetting a form
does reset its output elements.
The following example shows two input fields. Changing either field
updates an output element containing the product of both
fields.
<form> <p> <input name="a" type="number" precision="float" value="0"> * <input name="b" type="number" precision="float" value="0"> = <output name="result" onforminput="value = a.value * b.value">0</output> </p> </form>
This would work something like the following:
The forminput event
is defined in the section on new events.
textarea elementThe rows and cols attributes of the
textarea element are no longer required attributes. When
unspecified, CSS-compliant browsers should lay the element out as
specified by CSS, and non-CSS UAs may use UA-specific defaults, such as,
for visual UAs, using the width of the display device and a height
suitable for the device.
The textarea element may have a wrap attribute specified. This attribute
controls the wrapping behaviour of submitted text.
soft
hard
cols
attribute. (These additional line breaks can't be seen in the DOM.)
Authors should always specify a cols attribute when the
wrap attribute is set to hard. When wrap="hard" is specified
without a cols attribute, user agents should use the display
width when wrapping the text for submission. This will typically mean that
different users submit text at different wrapping widths, defeating much
of the purpose of client-side wrapping.
CSS UAs should render textarea elements as
specified by the 'white-space' property, although UAs may
have rules in their UA stylesheet that key the default 'white-space'
property values based on the wrap element
for textarea elements.
The maxlength attribute applies to
textarea controls.
File upload controls (input elements of type file) are not successful if the user enters a value that
specifies non-existent files. There is no error code for this situation
because that would open the way for some privacy or security leaks. It is
recommended that user agents report problems of this nature to the user.
The min and max attributes apply to file upload controls and
specify (as positive integers) how many files must be attached for the
control to be valid. They default to 0 and 1 respectively (and so limit
the default number of files to 1 optional file, as per most existing
implementatios in early 2004). The ERROR_RANGE_UNDERFLOW and ERROR_RANGE_OVERFLOW codes are used to
indicate when fields do not have the specified number of files selected.
The accept attribute may be used to
specify a comma-separated list of content types that a server processing
the form will handle correctly. This attribute was specified in [HTML4]. In this specification, this attribute is
extended as follows:
*, for example:
<input type="file" name="avatar" accept="image/*"/>In this way, the
accept attribute may
be used to specify that the server is expecting an image, a sound clip, a
video, etc, without specifying the exact list of types.
accept attribute's MIME
type list to determine which application to use.
One recent use for sound file upload has been the concept of audio blogging. This is similar to straight-forward Web logging, or diary writing, but instead of submitting textual entries, one submits sound bites.
The submission interface to such a system could be written as follows:
<form action="/weblog/submit" method="post" enctype="multipart/form-data"> <label> Attach your audio-blog sound file: <input type="file" name="blog" accept="audio/*"/> </label> <input type="submit" value="Blog!"/> </form>
A compliant UA could, upon encountering this form, provide a "Record" button instead of, or in addition to, the more usual "Browse" button. Selecting this button could then bring up a sound recording application.
This is expected to be most useful on small devices that do not have file systems and for which the only way of handling file upload is to generate the content on the fly.
accept attribute is set on a
form element, it sets the default for any file upload
controls in that form. (This is done by the file upload controls first
checking their attribute, and if they don't have one, checking their
form's. The two attributes don't "stack".)
The maxlength attribute applies to
file upload controls.
form elementThe form element's action
attribute is no longer a required attribute. If omitted, the default value
is the empty string, which is a relative URI pointing at the current
document (or the specified base URI, if any).
To support incremental updates of forms, a new attribute is introduced
on the form element: replace. This attribute takes two values:
target attribute when the document contains frames) is
replaced by the return value.
These names, and their exact semantics, differ from those
of the equivalent attribute in XForms 1.0 (the replace attribute on the
submission element). The equivalent of this specification's
document is equivalent to the XForms all, and
the equivalent of values is instance. The
equivalent of the XForms none value is document
with the server returning an HTTP 204 No Content return code.
The exact semantics are described in detail in the section on submission, under step nine.
Normally, activating a submit button (an input or
button element with the type attribute set to
submit, or an input
element with the type attribute set to image) submits the form, using the form's
submission details (action, method,
enctype, and replace
attributes).
In some cases, authors would like to be able to submit a form to
different processors, using different submission methods, or not replacing
the form but just updating the details with new data. For this reason, the
following attributes are allowed on submit buttons: action,
method, enctype, replace, and target. When not
specified, their values default to the values given by their
form element.
If a submit button is activated, then the submission uses the values as given by the button that caused the activation, with missing attributes having their values taken from the form.
In addition to the new attributes given in this section, some existing attributes from [HTML4] are clarified and extended below. These, and other attributes from HTML4, continue having the same semantics as described in HTML4 unless specified otherwise.
disabled
The disabled attribute applies to
all control types, including fieldset (in HTML4 the
disabled attribute did not apply to
the fieldset element), except the output
element.
maxlength
This attribute applies to text,
password and file input types,
and textarea elements. In particular, it does not apply to
the date-related, time-related, and numeric field types, or to the
email, tel, or uri
types. In HTML4, this attribute only applied to the
text and password types.
For text input controls it specifies the maximum length of the input, in terms of numbers of characters. For details on counting string lengths, see [CHARMOD].
When specified on a file upload control, it specifies the maximum size in bytes of the content.
The ERROR_TOO_LONG code is used when
this attribute is specified on a text,
password, or textarea
control and the control has more than the specified number of
characters, or when it is specifies on a file control and at least one of the selected
files is longer than the specified number of bytes.
Servers should still expect to receive, and must be able to cope with, content larger than allowed by the maxlength attribute, in order to deal with malicious or non-conforming clients.
name
Ecom_") in this
version of HTML forms have predefined meanings, allowing UAs to fill in
the form fields automatically. These names, and their semantics, are
described in [RFC3106].
readonly
text,
password, email, tel,
uri, date-related, time-related, and
numeric input types, as well as the textarea element.
Specifically, it does not apply to radio buttons, check boxes, file
upload fields, select elements, or
any of the button types; the interface concept of "readonly" values does
not apply to button-like interfaces. (The DOM readonly attribute ([DOM2HTML]) obviously applies to the same set of
types as the HTML attribute.)
Other attributes not listed in this specification retain the same semantics as in [HTML4].
pattern attributeFor the text, email, tel, and
uri types of the input
element
and the textarea element, a new attribute, pattern, is introduced to specify patterns
that the strings must match.
When specified, the pattern
attribute contains a regular expression that the field's value must match
before the form may be submitted (ERROR_PATTERN_MISMATCH).
<label> Credit Card Number:
<input type="text" pattern="^[0-9]{10}$" name="cc" />
</label>
The regular expression language used for this attribute is the same as
that defined in [ECMA262], except that the
pattern attribute implies a
^ at the start of the pattern and a $ at the end
(so the pattern must match the entire value, not just any subset). If the
attribute is empty or omitted then it is equivalent to .*
(which, with the implied start and end characters, becomes
^.*$), which matches anything.
In the case of the email, tel, and uri, the
pattern attribute specifies a pattern
that must be matched in addition to the value matching the
generic pattern relevant for the field. If the pattern given by the
attribute specifies a pattern that is incompatible with the grammar of the
field type, as in the example below, then the field could never be
satisfied. (A document containing such a situation is not technically
invalid, but it is of dubious semantic use.)
<form> <p> This form could never be submitted, as the following required field can never be satisfied: <input type="uri" pattern="^[^:]+$" required="required" name="test"/> </p> </form>
When the value doesn't match the field's type, a ERROR_TYPE_MISMATCH error occurs; when the value doesn't match the pattern, a ERROR_PATTERN_MISMATCH error occurs.
required attributeForm controls can have the required attribute specified, to
indicate that the user must enter a value into the form control before
submitting the form.
The required attribute applies to
all form controls except check boxes, radio buttons, controls with the
type hidden, image inputs, buttons,
fieldsets, and output elements. It can
be used on controls with the readonly
attribute set; this may be useful in scripted environments. For disabled
controls, the attribute has no effect.
The ERROR_REQUIRED code is used for form controls marked as required that do not have values.
Here is a form fragment showing two required fields and one optional field. A user agent would not allow the user to submit the form until the "name" and "team" fields were filled in.
<ul>
<li>Name: <input type="text" name="name" required="required" /></li>
<li>Team:
<select name="team" required="required">
<option value="foxes">The Foxes</option>
<option value="ferrets">The Ferrets</option>
<option value="kittens">The Kittens</option>
</select>
<li>Comment: <input type="text" name="comment" /></li>
</li>
</ul>
Any non-empty value satisfies the required condition, including a simple
whitespace character.
form attributeAll form controls can have the form attribute specified.
The form attribute gives the ID of the form
element the form control should be associated with, and overrides the
relationship between the form control and any ancestor form
element.
Setting an element's form attribute either to a
non-existent ID, to the empty string, or to an ID that identifies an
element that is not an HTML form element, disassociates the
form control from its form, leaving it unassociated with any
form.
When set on a fieldset element, this also changes the
association of any descendant form controls, unless they have
form attributes of their own, or are contained inside forms
that are themselves descendants of the fieldset element.
When forms are submitted, reset, or have their form controls enumerated through the DOM, only those controls associated with the form are taken into account. A control can be associated only with one form at a time.
A form attribute that specifies an ID that occurs multiple
times in a document should select the same form as would be selected by
the getElementById() method for that ID ([DOM3CORE]).
In this example, each row contains one form, even though without this attribute it would not be possible to have more than one form per table if any of them span cells.
<table>
<thead>
<tr>
<th>Name</th>
<th>Value</th>
<th>Action</th>
</tr>
</thead>
<tbody>
<tr>
<td>
<form id="edit1" action="/edit" method="post">
<input type="hidden" name="id" value="1"/>
<input type="text" name="name" value="First Row"/>
</form>
</td>
<td>
<input form="edit1" type="text" name="value"/>
</td>
<td>
<input form="edit1" type="submit" name="Edit"/>
</td>
</tr>
<tr>
<td>
<form id="edit2" action="/edit" method="post">
<input type="hidden" name="id" value="2"/>
<input type="text" name="name" value="Second Row"/>
</form>
</td>
<td>
<input form="edit2" type="text" name="value"/>
</td>
<td>
<input form="edit2" type="submit" name="Edit"/>
</td>
</tr>
</tbody>
</table>
autocomplete attributeAll form controls except the various push button controls and hidden and output controls, can
have the autocomplete attribute
set. The attribute takes two values, on and off.
The default, when the attribute is not specified, is on.
The on value means the UA is allowed to store the value entered by the user so that if the user returns to the page, the UA can pre-fill the form. The off value means that the UA must not remember that field's value.
Banks frequently do not want UAs to pre-fill login information:
<p>Account: <input type="text" name="ac" autocomplete="off" /></li> <p>PIN: <input type="text" name="pin" autocomplete="off" /></li>
In practice, this attribute is required by many banking institutions, who insist that UAs implement it before supporting them on their Web sites. For this reason, it is implemented by most major Web browsers already, and has been for many years.
inputmode attributeThe inputmode attribute applies
to the input element when it has a type
attribute of text, password, email, tel, or
uri,
and to the textarea element.
This attribute is defined to be exactly equivalent to the inputmode attribute defined in the XForms 1.0
specification (sections E1 through E3.2) [XForms].
help
attributeAny form control can have a help attribute specified. This
attribute contains a URI that the UA may use to provide help information
regarding the active field.
This specification does not specify how help information should be used, but for example, the UA could show a small pop-up window if the user focuses such a control and pressed the F1 key, or could show the help information in a side-bar while the relevant control is focused.
This attribute is added mainly because XForms has it, to
show that it would be trivial to add to HTML as well. However, there is
some doubt that it is actually a useful feature. The XForms
hint element is already supported in HTML, as the
title attribute.
There are several elements that are defined as expecting particular elements as children. Using the DOM, or in XML, it is possible for authors to violate these expectations and place elements in unexpected places.
Authors must not do this. User agent implementors may curse authors who violate these rules, and may persecute them to the full extent allowed by applicable international law.
Upon encountering such an invalid construct, UAs must proceed as follows:
form elements in head elements
in XHTML
head elements. No other special behaviour is required to
cope with this case; if the author overrides this hiding (e.g. through
CSS) then the form must behave like any other form. (This does not apply
to HTML, where a form in a head would, per SGML
parsing rules, imply a body start tag.)
input elements
output elements containing elements
defaultValue DOM attribute is initialized from the
DOM3 Core textContent attribute ([DOM3CORE]). Setting the element's
value attribute is defined to be identical to setting the
DOM3 Core textContent attribute. While the element contains
elements, they are rendered according to the CSS rules.
textarea elements containing elements
defaultValue DOM attribute is identical to the
textContent DOM attribute both for reading and writing, and
is used to set the initial value. The rendering is based on
the value DOM attribute, not the contents of the element,
unless CSS is used to override this somehow.
We could take the child text nodes instead. Or make it equivalent to editing the first text node. But doing it as textContent is the simplest from a specification point of view. Opinions?
select elements containing nodes other than
option and optgroup elements, and for
optgroup elements containing nodes other than
option elements
option and optgroup elements take
part in the select semantics. Unless otherwise forced to
appear by a stylesheet, other child nodes are never visible.
option elements containing nodes other than text
nodes
textContent DOM attribute's value.
As far as rendering goes, it is left largely up to the UA. Two possibilities are sensible: rendering the content normally, just as it would have been outside the form control; and rendering the initial value only, with the rest of the content not displayed (unless forced to appear through some CSS).
It should be noted that while nesting
a form inside a select control may look cool, it is
extremely poor UI and must not be encouraged.
option and optgroup elements that are
not inside select elements
span elements as
far as rendering goes.
min attribute on a datetime control is an integer instead of a
date and time string, then the range has no minimum. If the
type attribute is then changed to number, then the attribute would take effect.
for) to elements that are not
form controls
htmlFor) but the control DOM attribute must return null and
activating the label must not send focus to the associated element.
repeat elements with children or attributes other
than the index attribute
Other invalid cases should be handled analogously.
Occasionally forms contain repeating sections, for example an order form could have one row per item, with product, quantity, and subtotal fields. The repeating form controls model defines how such a form can be described without resorting to scripting.
The entire model can be emulated purely using JavaScript and the DOM. With such a library, this model could be used and down-level clients could be supported before user agents implemented it ubiquitously. Creating such a library is left as an exercise to the reader.
This subsection is not normative.
Occasionally, a form may have a section to be repeated an arbitrary number of times. For example, an order form could have one row per item. Traditionally, this has been implemented either by using complex client-side scripts or by sending a request to the server for every new row.
Using the mechanisms described in this section, the problem is reduced to describing a template in the markup, and then specifying where and when that template should be repeated.
To explain this, we will step through an example. Here is a sample form with three rows:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN">
<html>
<head>
<title>Sample Order Form</title>
</head>
<body>
<table>
<tr>
<th>Product</th>
<th>Quantity</th>
</tr>
<tr>
<td><input type="text" name="row0.product" value=""></td>
<td><input type="text" name="row0.quantity" value="1"></td>
</tr>
<tr>
<td><input type="text" name="row1.product" value=""></td>
<td><input type="text" name="row1.quantity" value="1"></td>
</tr>
<tr>
<td><input type="text" name="row2.product" value=""></td>
<td><input type="text" name="row2.quantity" value="1"></td>
</tr>
</table>
</body>
</html>
The template for those rows could look something like:
<tr>
<td><input type="text" name="row0.product" value=""></td>
<td><input type="text" name="row0.quantity" value="1"></td>
</tr>
...except that then the names would all be the same — all rows would be "row0", so there would be no clear way of distinguishing which "quantity" went with which "product" except by the order in which they were submitted.
To get around this, the template is modified slightly:
<tr id="order">
<td><input type="text" name="row[order].product" value=""></td>
<td><input type="text" name="row[order].quantity" value="1"></td>
</tr>
The template now has a unique identifier, and that identifier is used to
indicate where the row index should be substituted in. When a template is
replicated, all the attributes containing the template's id between square
bracket characters ([id]) have that ID replaced by
a unique index.
In order to distinguish this row from a normal row, however, something
needs to be added to the template to mark it as being a template. This is
done using a repeat
attribute:
<tr id="order" repeat="template">
<td><input type="text" name="row[order].product" value=""></td>
<td><input type="text" name="row[order].quantity" value="1"></td>
</tr>
If we replace the table with that markup:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN">
<html>
<head>
<title>Sample Order Form</title>
</head>
<body>
<table>
<tr>
<th>Product</th>
<th>Quantity</th>
</tr>
<tr id="order" repeat="template">
<td><input type="text" name="row[order].product" value=""></td>
<td><input type="text" name="row[order].quantity" value="1"></td>
</tr>
</table>
</body>
</html>
...then nothing but the header will appear! This is because templates
are not rendered. Templates have to be repeated. This is done
with the repeat element:
...
<tr id="order" repeat="template">
<td><input type="text" name="row[order].product" value=""></td>
<td><input type="text" name="row[order].quantity" value="1"></td>
</tr>
<repeat>
<repeat>
<repeat>
</table>
</body>
</html>
This is now identical to the original example. It still isn't dynamic — there is no way for the user to add more rows.
This can be solved by adding an add
button. The add button type adds a copy of
a template when the user presses the button, in much the same way as the
repeat element does.
There are two ways to use add buttons.
The first is by explicitly specifying which template should be replicated:
<p><input type="add" template="order" value="Add Row"></p>
The template is specified using a template attribute on the input
type="add" or button type="add" element. The template attribute contains an ID that should
match the ID of the template you want the button to affect.
When such a button is pressed, the template is replicated, and the resulting block is inserted just after the last block that is associated with the template. For example, there are three rows in the example above, so if the user pressed that button, the new block would be inserted just after the third one.
The second way is by including an add
button inside the template, so that when the template is replicated, the
button is replicated into the resulting block. When such a button is
pressed, the template is replicated, and inserted immediately before the
block in which the button is found. For example, if there were add buttons in the rows of the example above, and
someone pressed the button in the second row, a row would be inserted
between the first row and the second row.
For this example we will only use the first way:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN">
<html>
<head>
<title>Sample Order Form</title>
</head>
<body>
<table>
<tr>
<th>Product</th>
<th>Quantity</th>
</tr>
<tr id="order" repeat="template">
<td><input type="text" name="row[order].product" value=""></td>
<td><input type="text" name="row[order].quantity" value="1"></td>
</tr>
<repeat>
<repeat>
<repeat>
</table>
<p><input type="add" template="order" value="Add Row"></p>
</body>
</html>
Now the user can add more rows, but he cannot remove them. Removing rows
is done via the remove button type.
When a user presses such a button, the row in which the button is kept is
removed from the document.
<input type="remove" value="Remove This Row">
This is added to the template so that it appears on every row:
<tr id="order" repeat="template">
<td><input type="text" name="row[order].product" value=""></td>
<td><input type="text" name="row[order].quantity" value="1"></td>
<td><input type="remove" value="Remove This Row"></td>
</tr>
The final result looks like this:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN">
<html>
<head>
<title>Sample Order Form</title>
</head>
<body>
<table>
<tr>
<th>Product</th>
<th>Quantity</th>
</tr>
<tr id="order" repeat="template">
<td><input type="text" name="row[order].product" value=""></td>
<td><input type="text" name="row[order].quantity" value="1"></td>
<td><input type="remove" value="Remove This Row"></td>
</tr>
<repeat>
<repeat>
<repeat>
</table>
<p><input type="add" template="order" value="Add Row"></p>
<p><input type="submit" value="Submit"></p>
</body>
</html>
If the user pressed "Add" once, removed the middle two rows, typed in some garbage in the two "product" text fields, and pressed "Submit", the user agent would submit the following name-value pairs:
order0.product=some order0.quantity=1 order3.product=garbage order3.quantity=1
Further examples are given in the examples section below.
The repetition model supports more than just the cases given above, for
instance there are move-up and
move-down buttons that can be
inserted inside templates much like the remove button but for moving rows up and down.
Repetition templates can also be nested. The concept of hierarchy is expected to be represented in the names, as it is today in hand-rolled repeating forms, as in:
order1.name order1.quantity order1.comment1.text order1.comment2.text order2.name order2.quantity order2.comment1.text
That way the submission can remain compatible with the long-established
multipart/form-data, yet not lose the structure of the data.
The naming schemes used above are arbitrary. Any naming scheme could be used, at the convenience of the author.
The current repetition model can't declaratively limit the number of repeats (although you can write script to do this manually). This specification also does not address the ability to select a template to move it up or down without using buttons directly associated with the current template.
In this section, a number of references are made to namespaces. For authors who are only using HTML or XHTML, the definitions below ensure that no namespaces need appear in the document (except the namespace on the root element). Thus, such a reader can simply gloss over the parts that mention namespaces.
In order to implement such a form declaratively, a new global attribute
is introduced: the repeat attribute.
When placed on elements in the http://www.w3.org/1999/xhtml
namespace, it must be a namespace-free attribute, and when placed on other
elements, it must be an attribute in the
http://www.w3.org/1999/xhtml namespace.
The effect of this attribute depends on its value, which can be either
the literal string "template", or an
integer.
An element in the http://www.w3.org/1999/xhtml namespace
with the repeat attribute
in no namespace, or an element in any other namespace with the
repeat attribute in the
http://www.w3.org/1999/xhtml namespace, with the attribute's
value equal to template, is a repetition template.
Repetition templates may occur anywhere. They are not specifically associated with any form.
Every template has an index associated with it. The initial value of a
template's index is always 0. The index is used to ensure that when
cloning templates, the new block has a unique ID. The template's index
does not appear in the markup. (It does, however, appear in the DOM, as
the repetitionIndex
attribute.)
Unrecognized tokens must be ignored.
<div repeat="template"/> <!-- A template. --> <div repeat="template +1 3"/> <!-- Not a template. --> <div repeat=" template"/> <!-- Not a template (leading whitespace). -->
An element in the http://www.w3.org/1999/xhtml namespace
with the repeat attribute
in no namespace, or an element in any other namespace with the
repeat attribute in the
http://www.w3.org/1999/xhtml namespace, with the attribute's
value equal to an integer (an optional leading '-' character followed by
one or more decimal digits), is a repetition
block.
Repetition blocks should only occur as following siblings of repetition templates. If an element is declared as a repetition block but does not have a previous sibling that is a repetition template, then it can only take part in certain aspects of the repetition model (namely deletion and movement, and not addition). Such elements are termed orphan repetition blocks.
Every repetition block has an index associated with it. The index's
initial value is the value of the repeat attribute.
<div> <div repeat="template"/> <!-- The template for the next few elements. --> <div repeat="0"/> <!-- A simple repetition block, index 0. --> <div repeat="-5"/> <!-- Another, index -5 --> <div repeat="2"/> <!-- A simple repetition block, index 2. --> <div repeat="nothing"/> <!-- Just a normal element. --> <div repeat=" 3"/> <!-- Another normal element (leading whitespace). --> </div> <div repeat="0"/> <!-- Orphan repetition block, index 0. -->
Several new button types are introduced to support the repetition model.
These values are valid types for both the input element and
the button element.
add
remove
move-up
move-down
These control types can never be successful.
Invoking these buttons generates events (for instance
click), as specified by the DOM specifications. The default
action for these events is to act as described below. However, if the
event is cancelled, then the default action will not occur.
In addition, to support the add type, a
new attribute is introduced to the input and
button elements: template.
template
These are described in more detail in the next section.
The repetition model includes several events. These use the following interface to store their context information.
/* Similar to the UIEvent interface */
interface RepetitionEvent : Event {
readonly attribute RepetitionElement element;
void initRepetitionEvent(in DOMString typeArg,
in boolean canBubbleArg,
in boolean cancelableArg,
in RepetitionElement elementArg);
void initRepetitionEventNS(in DOMString namespaceURIArg,
in DOMString typeArg,
in boolean canBubbleArg,
in boolean cancelableArg,
in RepetitionElement elementArg);
};
The initRepetitionEvent() and
initRepetitionEventNS() methods have the same behaviours as
the initEvent() and initEventNS() events from [DOM3EVENTS].
A repetition template should not be displayed. In CSS-aware user agents, this should be achieved by including the following rules, or their equivalent, in the UA's user agent stylesheet:
@namespace html url(http://www.w3.org/1999/xhtml);
:not(html|*)[html|repeat="template"],
html|*[|repeat="template"] { display: none; }
Any form controls inside a repetition
template are associated with their form's
templateElements DOM attribute, and are not present
in the form's elements DOM attribute, unless the relevant
form is inside the template itself. Since controls in the
templateElements attribute cannot be successful, controls inside repetition templates
that would be part of forms outside the template can never be submitted
and cannot be pre-filled directly when the form is pre-seeded. However,
see the section on seeding a form with initial values for
details on how repetition blocks can be pre-filled.
If an add button is activated, and it
has a template attribute, and the
element, in the same document, with the ID given by the template attribute in question, is a repetition template as defined above, then
that element's template replication behaviour is invoked. (Specifically,
in scripting-aware environments, the element's addRepetitionBlock() method is
called with a null argument.)
If an add button is activated, and it
has no template attribute, but the
element has an ancestor that is a repetition
block that is not an orphan repetition block, then
the repetition template associated
with that repetition block has its template replication behaviour invoked
with the respective repetition block as its argument. (Specifically, in
scripting-aware environments, the element's addRepetitionBlock() method is
called with a reference to the DOM Element node that represents the
repetition block.)
When a template's replication behaviour is invoked (specifically, when
either its addRepetitionBlock() method is
called or its addRepetitionBlockByIndex()
method is called) the following is performed:
addRepetitionBlockByIndex()
method, and the value of the method's index argument is greater than the
template's index, then the template's index is set to the value of index
argument.
addRepetitionBlockByIndex()
method, the new repetition block element's index is set to the method's
index argument. Otherwise, the new repetition block element's index is
set to the template's index.
http://www.w3.org/1999/xhtml namespace, then the
repeat attribute in no namespace on the cloned element has
its value changed to the new block's index. Otherwise, the
repeat attribute in the
http://www.w3.org/1999/xhtml namespace has its value changed
to the new block's index.
order", and the new repetition block's index has the value
2, and one of the attributes of one of the descendents of the new
repetition block is
"order.[order].comment.[comment[order]]", then the
attribute's value is changed to
"order.2.comment.[comment2]".) This is performed without
paying attention to the types of attributes, and is done to all
descendants, even those inside nested forms, nested repetition templates,
and so forth.
added event in the data:,repetition
namespace, which bubbles but is not cancellable and has no default
action, is fired on the repetition template with the repetition block's
DOM node as the context information.
For an example, see the example section below.
If a remove button is activated, and
the element has an ancestor that is a repetition block as defined above, then the
nearest such ancestor's template deletion behaviour is invoked.
(Specifically, in scripting-aware environments, the element's removeRepetitionBlock() method is
invoked.)
When a repetition block's deletion behaviour is invoked (specifically,
when its removeRepetitionBlock()
method is called) the following is performed:
removed event in the data:,repetition
namespace, which bubbles but is not cancellable and has no default
action, is fired on the element's repetition template, if it has one,
with the repetition block's DOM node as the context information.
This occurs even if the repetition block is an orphan repetition block (although if is, the event is not fired).
For an example, see the example section below.
The two remaining button types, move-up and move-down, are used to move the current
repetition block up or down the sibling repetition blocks.
If a move-up or move-down button is activated, and the
element has an ancestor that is a repetition
block as defined above, then the nearest such ancestor's
template movement behaviour is invoked in the relevant direction.
(Specifically, in scripting-aware environments, the element's moveRepetitionBlock() method is
called; for move-up buttons the
argument is -1 and for move-down
buttons the argument is 1).
When a repetition block's movement behaviour is invoked (specifically,
when its moveRepetitionBlock() method
is called) the following is performed, where distance is an
integer representing how far and in what direction to move the block (the
argument to the method):
previousSibling is defined and
is not a repetition template, set
target to this previousSibling and, if it is a
repetition block, increase
distance by one (make it less negative by one).
nextSibling is defined
and is not a repetition template,
set target to this nextSibling and, if it is a
repetition block, decrease
distance by one. After the loop, set target to
target's nextSibling (which may be null).
insertBefore()
method with the newChild argument being the repetition block
and the refChild argument being target (which may
be null by this point). Mutation events are fired if appropriate.
moved event in the data:,repetition
namespace, which bubbles but is not cancellable and has no default
action, is fired on the element's repetition template (if it has one)
with the repetition block's DOM node as the context information.
This occurs even if the repetition block is an orphan repetition block (although if is, the event is not fired).
Moving repetition blocks does not change the index of the repetition blocks.
In addition, user agents must automatically disable move-up buttons (irrespective of the value of
the disabled DOM attribute) when
their repetition block could not be moved any higher according to the
algorithm above, and when the buttons are not in a repetition block.
Similarly, user agents must automatically disable move-down buttons when their repetition block
could not be moved any lower according to the algorithm above, and when
the buttons are not in a repetition block. This automatic disabling does
not affect the DOM disabled property.
It is an intrinsic property of these buttons.
The repeat element in the
http://www.w3.org/1999/xhtml namespace is used to insert
repetition blocks without having to explicitly copy the repetition
template markup in the source document.
Authors can specify the index of the new repetition block by using the
index attribute.
Upon being inserted into a document, repeat elements are
immediately replaced by a repetition block created by the appropriate
repetition template. The exact set of events that UAs must implement is as
follows:
repeat element is inserted into the document, either
via script or during parsing. Mutation events are fired if appropriate.
repeat element
has an index attribute, and the attribute is an integer (an
optional leading '-' character followed by one or more decimal digits)
then the template's addRepetitionBlockByIndex()
method is invoked, with a reference to the repeat element as
the first argument, and the value of the index attribute as
the second argument.
addRepetitionBlock() method is
invoked, with a reference to the repeat element as the
argument.
repeat element is removed from its parent node.
Mutation events are fired if appropriate.
The repeat element in HTML is an EMPTY element, so it has
no end tag.
The next section shows an example.
This section gives some more practical examples of repetition.
The following example shows how to use repetition templates to dynamically add more rows to a form in a table.
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN">
<html>
<head>
<title>Form Repeat Demo</title>
</head>
<body>
<form action="http://software.hixie.ch/utilities/cgi/test-tools/echo" method="post" enctype="multipart/form-data">
<table>
<thead>
<tr>
<th>Name</th>
<th>Number of Cats</th>
<th></th>
</tr>
</thead>
<tbody>
<tr repeat="template" id="row">
<td><input type="text" name="name_[row]" value=""></td>
<td><input type="text" name="count_[row]" value="1"></td>
<td><input type="remove" value="Delete Row"></td>
</tr>
<tr repeat="repeated">
<td><input type="text" name="name_0" value="John Smith"></td>
<td><input type="text" name="count_0" value="2"></td>
<td><input type="remove" value="Delete Row"></td>
</tr>
<repeat>
</tbody>
</table>
<p>
<input type="add" value="Add Row" template="row">
<input type="submit">
</p>
</form>
</body>
</html>
Initially, two rows would be visible, each with two text input fields,
the first row having the values "John Smith" and "2", the second row
having the values "" (a blank text field) and "1". The second row is the
result of the repeat
element being replaced by a repetition block while the document
was being loaded.
If the "Add Row" button is pressed, a new row is added. The first such row would have the index 2 (since there are already two repetition blocks numbered 0 and 1) and so the controls would be named "name_2" and "count_2" respectively.
If the "Delete Row" button above is pressed, the row would be removed.
The previous example does not demonstrate nested repeat blocks, reordering repetition blocks, and inserting new repetition blocks in the middle of the existing sequence, all of which are possible using the facilities described above.
This example shows nested repeats.
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Solar System</title>
</head>
<body>
<form>
<h1> Solar system </h1>
<p> <label> System Name: <input name="name"/> </label> </p>
<h2> Planets </h2>
<ol>
<li repeat="template" id="planets">
<label> Name: <input name="planet[planets].name" required="required"/> </label>
<h3> Moons </h3>
<ul>
<li repeat="template" id="planet[planets].moons">
<input name="planet[planets].moon[planet[planets].moons]"/>
<input type="remove" value="Delete Moon"/>
</li>
</ul>
<p><input type="add" template="planet[planets].moons" value="Add Moon"/></p>
<p><input type="remove" value="Delete Planet"/></p>
</li>
</ol>
<p><input type="add" template="planets" value="Add Planet"/></p>
<p><input type="submit"/></p>
</form>
</body>
</html>
Note that to uniquely identify each nested repeat (which is required
since the add buttons are dependent on IDs
to specify which template should have a block added), the IDs of the
nested templates are specified in terms of the ancestor template's ID,
using the index substitution feature.
Since square brackets are not allowed in ID attributes in XML, the above example cannot validate. It is still well-formed, however.
The following events are considered form events:
Some of the above are mainly described in [DOM3EVENTS] and [HTML4]. This section introduces the new events and new semantics for the existing events.
The scope chain for ECMAScript executed in HTML event handler attributes
links from the activation object for the handler, to its this
parameter (the event target), to the form, to the document, to the default
view (the window).
The event handler is passed one argument, event, corresponding to the event object.
This definition is intentionally backwards compatible with DOM Level 0. See also ECMA-262 Edition 3, sections 10.1.6 and 10.2.3, for more details on activation objects. [ECMA262]
In [DOM3EVENTS] and [HTML4], the change event is fired on a
form control element when the control loses the input focus and its value
has been modified since gaining focus.
To address the need for more immediate feedback mechanisms, this
specification introduces the input
event. This event is fired on a control whenever the value of the
control changes due to input from the user, and is otherwise identical to
the change event. (For example, it bubbles, is not
cancelable, and has no context information.)
Change and input events must never be triggered by scripted changes to the control value. Thus, loops caused by change event handlers triggering changes are not usually possible.
Any element that accepts an onchange attribute to handle
change events also accepts an oninput attribute
to handle input events.
Sometimes form controls are inter-dependent. In these cases, it is more
intuitive to specify the dependencies on the control whose value or
attributes depend on another's, rather than specify which controls should
be affected by a change on the element that changes. For this reason, two
new events are introduced, formchange and forminput.
These events are in the same namespace as the other form events, do not bubble, cannot be canceled, have no context information, and have no default action.
The default action of a change event is to fire a formchange event at each element in the
form's elements, in document order, and finally at the form
itself. Note that template controls are not affected. If authors need this
event to affect template controls, they should hook into the form's
onformchange event handler.
The input element analogously invokes the forminput event as its default action.
When a form is reset, a formchange event is fired on all the form
controls of the form.
With the introduction of the various type checking mechanisms, some way
for scripting authors to hook into the type checking process is required.
This is provided by the new invalid
event (in the http://www.w3.org/2001/xml-events namespace).
Can we put that event into that namespace?
When a form is submitted, each successful control in that form, in document order,
is checked for validity. Then, once all the controls have been checked and
the list of invalid controls, and how they are invalid, has been
established, an invalid event must be
fired on the control for each control that fails to comply with its
constraints and is still a member of the form when the event is to be
fired (i.e. each control whose validity attribute is non-zero at the start of
this process).
This definition implies a defined behaviour in the face
of event handlers that mutate the document. For example, if one control's
oninvalid attribute changes a later control's value from
invalid to valid, the event is still fired on that later control. Controls
added to the form during the process will not have any events fired, even
if their value is invalid. Controls invalid at the start of the process
that are removed from the form before receiving their events simply don't
receive the event. Controls that change from one invalid state to another
invalid state before receiving their event receive an event that describes
their state at the start of the process before any events were
fired.
The event can also be fired if the validate() method of a form control is invoked
via script.
The oninvalid attribute (on input,
textarea and select elements) can be used to
write handlers for this event.
This event bubbles and is cancelable. The default action depends on when the event was fired.
If it was fired during form submission, then the default action is
UA-specific, but is expected to consist of focusing the element (possibly
firing focus events if appropriate), alerting the user that the entered
value is unacceptable in the user's native language along with explanatory
text saying why the value is currently invalid, and aborting the
form submission. UAs would typically only do this for the first form
control found to be invalid; while the event is dispatched to all
successful but invalid controls, it is simpler for the user to deal with
one error at a time. If the element causing trouble is not visible (for
example a field made invisible using CSS or a field of type hidden) then the UA may wish to indicate to the
user that there may be an error with the page's script.
This specification currently does not specify what should
happen if some events are cancelled and some are not. A future version of
this specification may specify this in more detail based on implementation
feedback and user experience. Authors are encouraged to either cancel all
invalid events (if they wish to handle
the error UI themselves) or to not cancel any (if they wish to leave the
error UI to the UA).
When fired by script calling the validate() method (i.e. not during form
submission), the event has no default action.
The following example shows one way to use this event.
<form action="..." method="post">
<p>
<label>
Byte 1:
<input name="byte" type="number" min="0" max="255" required="required"
oninvalid="failed(event)" />
</label>
<output name="error"/>
</p>
<script type="text/javascript"> <![CDATA[
function failed(event) {
// a control can fail for more than one reason; only report one of them.
form.error.value = 'The value is wrong for a reason I did not expect.';
if (event.target.validity & event.target.form.ERROR_TYPE_MISMATCH)
form.error.value = 'That is not an integer.';
else if (event.target.validity & event.target.form.ERROR_PRECISION_EXCEEDED)
form.error.value = 'That is not an integer.';
else if (event.target.validity & event.target.form.ERROR_RANGE_UNDERFLOW)
form.error.value = 'That integer is less than 0.';
else if (event.target.validity & event.target.form.ERROR_RANGE_OVERFLOW)
form.error.value = 'That integer is more than 255.';
else if (event.target.validity & event.target.form.ERROR_REQUIRED)
form.error.value = 'You did not enter a value.';
event.preventDefault(); /* don't want the UA to do its own reporting */
}
]]> </script>
</form>
The ReceivedEvent interface
is used in the form submission process to handle the results of form
submission.
interface ReceivedEvent : Event {
readonly attribute Document document;
void initReceivedEvent(in DOMString typeArg,
in boolean canBubbleArg,
in boolean cancelableArg,
in Document documentArg);
void initReceivedEventNS(in DOMString namespaceURIArg,
in DOMString typeArg,
in boolean canBubbleArg,
in boolean cancelableArg,
in Document documentArg);
The initReceivedEvent() and
initReceivedEventNS() methods have the same behaviours as the
initEvent() and initEventNS() events from [DOM3EVENTS].
The document argument contains a reference to the document
that was the result of the form submission. If the result cannot be
represented as a DOM document, then the attribute is null. The document is
mutable.
Processors conforming to this specification must use a slightly different algorithm than the [HTML4] form submission algorithm (HTML4 section 17.13.3), as described in this section.
When the user agent submits a form, it must perform the following steps.
submit event.
If the submission was not initiated using the submit() method then the submit event is submitted as described in [HTML4]. If it is canceled, then the submission
processing stops at this point. If it is not cancelled, then its default
action is to perform the rest of the submission procedure.
If the form submission was initiated as a result of a submit event's default action, then the form
is checked for validity. If this step
fails (that is, if any invalid
events are fired), the submission is aborted.
Otherwise, if the form submission was initiated via the submit() method, then instead of firing
invalid events, an exception is
raised (and submission is aborted) if any of the controls are invalid.
Specifically, a SYNTAX_ERR exception is raised. [DOM3CORE]
Script authors who wish to validate the form then perform submission can use script such as:
if (form.validate())
form.submit();
...with the controls having event handlers that report the errors.
All the controls that apply to the form, whether successful or not,
should be taken, in document order. These controls are all those whose
form DOM attribute points at the form and that are not in
the form's templateElements DOM attribute (this excludes
certain controls as specified in the section describing the
repetition model).
A form data set is a sequence of control-name, index, current-value triplets constructed from the controls identified in the previous step.
The index here is unrelated to the repetition index mentioned earlier.
It is constructed by iterating over the form controls listed in step three, taking note of the form control names as they are seen. With each control, if it is the first time that control's name has been seen, then the control is assigned an index of 0. Otherwise, if the control name was associated with an earlier control, then the index assigned is exactly one more than the last control with that name. Even unsuccessful controls and controls with no value are so numbered. However, only successful controls are added to the form data set.
Successful controls have exactly one value, except for
select controls and file upload controls, which have zero
or more values depending on how many items or files they have selected.
A successful control with more than one value is added multiple times,
one for each value (each time with the same form control name and form
control index). A successful control with zero values is omitted from
the form data set.
Image buttons, during this step, are handled as if they were two
controls, one with the control's name with .x appended,
whose value is the x coordinate selected by the user, and the other with
the control's name with .y appended, whose value is the y
coordinate selected by the user. The indices of these two virtual
controls are handled separately and could, depending on the values of
other controls, end up with different values.
For example, the following form:
<form>
<p> <label> Name: <input type="text" name="username"/> </label> </p>
<p> Lottery numbers:
<input name="number" type="number" min="1" max="49"/>
<input name="number" type="number" min="1" max="49"/>
<input name="number" type="number" min="1" max="49"/>
<input name="number" type="number" min="1" max="49"/>
<input name="number" type="number" min="1" max="49"/>
</p>
<p>
<label>
Games:
<select name="type" multiple="multiple">
<option value="Thunderbolt"> Thunderbolt </option>
<option value="Lightning"> Lightning </option>
</select>
</label>
</p>
<p>
<input type="submit" value="Send">
</p>
</form>
...if filled in with the name "Erwin" and the numbers 20, 30 and 40 with the first and last number fields left blank, and all the values in the select list selected, would generate the following form data set:
The form data set also includes a list of which repetition blocks are involved in the submission.
For each control in the form data set, the control and the control's ancestors are examined, up to but not including the first node that is a common ancestor of the control and the form, or is the form itself. For each element so examined, if it is a repetition block that is not an orphan repetition block and whose template does have an ID, and that repetition block has not yet been added to the list of repetition blocks, it is added.
The form data set is then encoded according to the content type
specified by the method and enctype attribute
of the element that caused the form to be submitted. See the semantics of method and
enctype attributes section for details on how the
action and enctype attributes are to be
treated. The possible values of enctype defined by this
specification are:
application/x-www-form-urlencoded
multipart/form-data
application/x-www-form+xml
text/plain
Other values may be defined by other specifications.
During this step, the form data set is examined to ensure all the characters are representable in the submission character encoding.
Finally, the encoded data is sent to the processing agent designated
by the action attribute of the element that initiated the
submission using the protocol method specified by the
method attribute of that same element. The semantics of method and
enctype attributes section describes this in more
detail.
received event.
This step must be skipped if the form has no onreceived attribute. If this step is not
skipped. then it defeats any attempt at incremental rendering, as the
entire return value from the server must be downloaded and parsed before
the event is fired (unless the user agent instantiates the document
lazily).
The received event is fired on
the form element. This event does not bubble. The onreceived attribute can be used to
handle this event.
The event uses the ReceivedEvent interface described
below.
If it is canceled, then the submission processing stops at this point.
If it is not cancelled, then its default action is to perform the rest
of the submission procedure (step nine). If the document
attribute of the event was mutated, the mutated version is what is used
in the next step.
If the response is an HTTP 204 No Content response (or equivalent for other protocols), then the document is left in place, and new metadata (if any) is applied. as per the HTTP specification [RFC2616].
Otherwise, how the UA responds to a response depends on the replace attribute of the element that
initiated the submission.
For replace="document" (the default), the response body
replaces the document from which the submission initiated (or, if there
is a target attribute, the document in the appropriate
frame).
For example if the action denotes an HTTP
resource, method is "POST", the replace attribute is document
and the remote server replies with a 200 OK response, then
the returned document should be displayed to the user as if the user had
navigated to that document by following a link to it.
For replace="values", the algorithm described in the
section on seeding a form with initial values
must be run with the given response body used instead of the document
mentioned in the data attribute. (Any target attribute is
ignored.)
All form controls are successful except:
templateElements list
(those inside repetition templates).
button, reset, add, remove,
move-up, or move-down.
Controls do not have to have a value to be successful.
Unsuccessful controls are not checked for validity during submission (although their flags are still set appropriately).
The different form data set encoding types each define how to find the character encoding to use to submit the data.
Sometimes, the form submission character set used is not able to represent all the character present in the form submission.
If the form data set contains characters that are outside the submission character set, the user agent should inform the user that his submission will be changed, for example using a dialog in the form:
____________________________________________________ || Warning ||||||||||||||||||||||||||||||||||||||||||| | | | This form cannot handle some of the characters you | | have entered. The data will be sent as "D?rst". | | | | (( Send anyway )) ( Return to form ) | `----------------------------------------------------'
If the submission is not canceled, the user agent MUST replace each character that is not in the submission character set with one or more replacement characters.
For each such missing character, UAs must either transliterate the character to a UA-defined human-recognizable representation (for example transliterating U+263A to the three-character string ":-)" in US-ASCII, or U+2126 to the byte 0xD9 in ISO-8859-7), or, for characters where a dedicated transliteration is not known to the UA, replace the character with either U+FFFD, "?", or some other single character representing the same semantic as U+FFFD.
Note that a string containing the codepoint's value itself (for example the six-character string "U+263A" or the seven-character string "☺") is not considered to be human readable and must not be used as a transliteration. (This is to discourage servers from attempting to mechanically convert such codepoints back into Unicode characters, as there is no way to distinguish such characters from identical literal strings entered by the user.)
application/x-www-form-urlencodedThis section defines the expected behaviour for step 5, "Step five:
Encode the form data set", of the submission algorithm described above,
for the form content type application/x-www-form-urlencoded.
The rest of the form submission process progresses as described above.
This is the default content type. Forms submitted with this content type must be encoded as follows:
accept-charset attribute. UAs must use the encoding that
most completely covers the characters found in the form data set of the
encodings specified. If the attribute is not specified, then the client
should use either the page's character encoding, or, if that cannot
encode all the characters in the form data set, UTF-8. Character
encodings that are not mostly supersets of US-ASCII must not be used
(this includes UTF-16 and EBCDIC) even if specified in
accept-charset attribute.
How a UA establishes the page's character encoding is determined by the language specification. It could be explicitly specified by the page, overriden by the user, or auto-detected by the UA. For example, HTML4 section 5.2.2 [HTML4].
hidden with the name _charset_, it
is forced to appear in the form data set, with the value equal to the
name of the submission character encoding used.
Note that the index and repetition block parts of the form data set are not used.
application/x-www-form+xml: XML submissionThis section defines the expected behaviour for step 5, "Step five:
Encode the form data set", of the submission algorithm described above,
for the form content type application/x-www-form+xml. The
rest of the form submission process progresses as described above.
The message entity is an XML 1.1 document, encoded as UTF-8, which has a
root element named "submission", with no prefix, defining a default
namespace data:,formData. UAs must include an XML
declaration.
Note that the form's accept-charset attribute is ignored
for this encoding type.
First, for each repetition block in the form data set, an element
repeat is inserted, with an attribute template equal to the ID of the template, and
an attribute index equal to the index of the repetition
block. The element is empty.
Servers are generally expected to ignore repeat elements;
they are primarily included so that form data can be round-tripped using
the data attribute on the form element.
Then, for each successful control that is not
a file upload control, in the order that the controls are to be found in
the original document, an element field is inserted, with an
attribute name having the name of the
form control, an attribute index having the index described
above in the definition of the form data
set, and with the element content being the current
value of the form control. Form controls with multiple values
result in multiple field elements being inserted into the
output, one for each value, all with the same index.
File controls are submitted using a file element instead of a field
element. The file element has four
attributes, name, index,
filename, and type. The name attribute contains the name of the file
control. The index attribute contains the index in the
control's entry in the form data set. The filename attribute
is optional and may contain the name of the file. The type
attribute is also optional and must contain the MIME type of the file, or
be omitted if the client is unaware of the correct type. The type may
contain MIME parameters if appropriate. The contents of the file are
base64 encoded and then included literally as content directly inside the
file element. As base64 data is
whitespace-clean, UAs may introduce whitespace into the file element to ensure the submitted data has
reasonable line lengths. This is, however, completely optional. (It is
primarily intended to make it possible to write readable examples of
submission output.)
UAs may use either CDATA blocks, entities, or both in escaping the contents of attributes and elements, as appropriate. The resulting XML must be a well-formed XML instance. The only mention of namespaces in the submission document must be the declaration of the default namespace on the root element.
Whitespace may be inserted around elements that are children of the
submission element in order to make the submitted data easier
to scan by eye. However, this is optional. Processors should not be
affected by such whitespace, or whitespace inside file elements, when reading the submitted data
back from the XML instance. (Whitespace inside field elements
is significant, however.)
The following example illustrates
application/x-www-form+xml encoding. Suppose we have the
following form:
<form action="http://example.com/cgi/handle"
enctype="application/x-www-form+xml"
method="post">
<p>
<label> What is your name? <input type="text" name="submit-name"/> </label>
<label> What files are you sending? <input type="file" name="files"/> </label>
<label> When were they written? <input type="date" name="stamp"/> </label>
<input type="submit" value="Send">
</p>
</form>
If the user enters "Larry" in the text input, selects the text file "file1.txt", and picks an arbitrary date, the user agent might send back the following data:
Content-Type: application/x-www-form+xml <submission xmlns="data:,formData"> <field name="submit-name" index="0">Larry</field> <file name="files" index="0" filename="file1.txt" type="text/plain;charset=iso-8859-1"> Y29udGVudHMgb2YgZmlsZTEudHh0 </file> <field name="stamp" index="0">1979-04-13</field> </submission>
If the user selected a second (image) file "file2.png", and changes the date, the user agent might construct the entity as follows:
Content-Type: application/x-www-form+xml <submission xmlns="data:,formData"> <field name="submit-name" index="0">Larry</field> <file name="files" index="0" filename="file1.txt" type="text/plain;charset=iso-8859-1"> Y29udGVudHMgb2YgZmlsZTEudHh0 </file> <file name="files" index="0" filename="file2.png" type="image/png"> iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAMAAAAoyzS7AAAABGdBTUEAAK /INwWK6QAAABl0RVh0U29mdHdhcmUAQWRvYmUgSW1hZ2VSZWFkeXHJZTwA AAAGUExURQD/AAAAAG8DfkMAAAAMSURBVHjaYmAACDAAAAIAAU9tWeEAAA AASUVORK5CYII= </file> <field name="stamp" index="0">1979-12-27</field> </submission>
Note how the content of the plain text attached file is base64-encoded, despite being a plain text file. This preserves the integrity of the file in cases where the MIME type is incorrect. It also means that files with malformed content, for example a file encoded as UTF-8 with stray continuation bytes, will be transmitted faithfully instead of being re-encoded by the UA.
This example illustrates this encoding for the case with two form controls with the same name. Suppose we have the following form:
<form enctype="application/x-www-form+xml" method="post"> <p> Enter your new password twice: <input type="password" name="password"/> <input type="password" name="password"/> <input type="submit" value="Send"> </p> </form>
If the user enters "perfect" and "prefect", the user agent might send back the following data:
Content-Type: application/x-www-form+xml <submission xmlns="data:,formData"> <field name="password" index="0">perfect</field> <field name="password" index="1">prefect</field> </submission>
Recall the example for repetition blocks. If it was immediately submitted, the output would be an XML file equivalent to:
Content-Type: application/x-www-form+xml <submission xmlns="data:,formData"> <repeat template="row" index="0"/> <field name="name_0" index="0">John Smith</field> <field name="count_0" index="0">2</field> <field name="name_1" index="0"></field> <field name="count_1" index="0">1</field> </submission>
text/plainThis section defines the expected behaviour for step 5, "Step five:
Encode the form data set", of the submission algorithm described above,
for the form content type text/plain. The rest of the form
submission process progresses as described above.
This content type is more human readable than the others but is not unambiguously parseable. Forms submitted with this content type must be encoded as follows:
accept-charset attribute. UAs must use the encoding that
most completely covers the characters found in the form data set of the
encodings specified. If the attribute is not specified, then the client
should use either the page's character encoding, or, if that cannot
encode all the characters in the form data set, UTF-8.
How a UA establishes the page's character encoding is determined by the language specification. It could be explicitly specified by the page, overriden by the user, or auto-detected by the UA. For example, HTML4 section 5.2.2 [HTML4].
hidden with the name _charset_, it
is forced to appear in the form data set, with the value equal to the
name of the submission character encoding used.
Note that the index and repetition block parts of the form data set are not used.
This algorithm does not directly parallel the algorithm for
application/x-www-form-urlencoded. This is mostly due to
backwards compatibility concerns.
method and enctype attributesThe exact semantics of the method and enctype
attributes depend on the protocol specified by the action
attribute, in the manner described in this section.
The attributes considered are those of the element that initiated the submission — if the user started the submission then the attributes come from the submit button or image that the user activated; if script started the submission then the attributes of the form are used. If an attribute is missing from a submit button, then the equivalent attribute on the form is used instead.
In the following example:
<form action="test.php" method="post"> <input type="submit"> <input type="submit" method="get"> </form>
The first submit button would submit to the test.php
script using the HTTP POST method, and the second would submit to the
same script but using the HTTP GET method.
The HTTP specification defines various methods that can be used with
HTTP URIs. Four of these are allowed as values of the method
attribute: get, post, put, and
delete. In this specification, these method names are applied
to other protocols as well. This section defines how they should be
interpreted.
If the specified method is not one of get,
post, put, or delete then it is
treated as get in the tables below.
If the enctype attribute is not
specified (or is set to the empty string), and the form consists of
exactly one file upload control with exactly one file selected, then in
the tables below, the "File upload" rows should be used. If the form
contains more than just one file upload control with exactly one file
selected, or if the attribute is specified but has on
unrecognised value, the enctype attribute is treated as if it
was application/x-www-form-urlencoded.
User agents may implement whichever URI schemes are required for their particular application. This specification does not specify a required core set of protocols that must be implemented.
What user agents should do when the designated resource is fetched
depends on the value of the replace
attribute. This is described in step nine of
the algorithm.
http:
actionsHTTP is described by [RFC2616].
| get | post | put | delete | |
|---|---|---|---|---|
| application/x-www-form-urlencoded | Use the encoded data set as the query value for a URI formed from
the action URI and fetch it via HTTP GET.
| Use the encoded data set as the entity body,
with the Content-Type set appropriately, and submit it
using the specified method.
| Ignore the form data set and access action
with the specified method.
| |
| multipart/form-data | Handle as if enctype was
application/x-www-form-urlencoded.
| |||
| application/x-www-form+xml | ||||
| text/plain | ||||
| File upload | Use the file content as the entity body, with the
Content-Type set to its MIME type, and submit it using the
specified method.
| |||
ftp:
actionsThe ftp: URI scheme is described by [RFC1738] and FTP itself is described by [RFC959].
Using the FTP protocol for form submission is of dubious value and is discouraged.
| get | post | put | delete | |
|---|---|---|---|---|
| application/x-www-form-urlencoded | Ignore the form data set and retrieve the file specified
by action (RETR).
| Handle as if method was put.
| Use the encoded data set as the content of a file and
upload it to the location specified by action
(STOR). The response body has no content (equivalent to an
HTTP 204 No Content response.)
| Ignore the form data set and delete the file specified
by action (DELE). The response body has no
content (equivalent to an HTTP 204 No Content response.)
|
| multipart/form-data | ||||
| application/x-www-form+xml | ||||
| text/plain | ||||
| File upload | Upload the selected file to the location specified by the
action URI (STOR). The response body has no
content (equivalent to an HTTP 204 No Content response.)
|
Using these semantics, a poor man's FTP upload form could be written like so:
<form method="put" xmlbase="ftp://ftp.example.com/incoming/">
<p>
<legend>
Path:
<input type="text" pattern="[^./][^/]*"
onchange="if (validity == 0) form.action = encodeURIComponent(value)"/>
</legend>
<input type="file" name="file"/>
<input type="submit" value="Upload file"/>
</p>
</form>
data:
actionsThe data: URI scheme is described by [RFC2387].
| get | post | put | delete | |
|---|---|---|---|---|
| application/x-www-form-urlencoded | Ignore the form data set and access the action URI.
| URI escape the encoded form data set and substitute it
for the first occurance of the string '%%' in the action
(if any), then access the resulting URI.
| Ignore action, and form a new data: URI
from the entity body, using the appropriate MIME type.
| Handle as if method was post.
|
| multipart/form-data | Handle as if enctype was
application/x-www-form-urlencoded.
| |||
| application/x-www-form+xml | ||||
| text/plain | ||||
| File upload | Ignore action, and form a new data: URI from the
selected file's contents, using the file's MIME type.
|
Note that '%%' is invalid in a URI, so authors should exercise caution
when using the post method with data: URIs..
file: actionsThe file: URI scheme is described by [RFC1738].
For security reasons, untrusted content should never be allowed to
submit or fetch files specified by file
URIs.
The semantics described in this subsection are recommended, but UAs may
implement alternative semantics as consistent behaviour for submission to
file: URIs is not required for
interoperability on the World Wide Web.
| get | post | put | delete | |
|---|---|---|---|---|
| application/x-www-form-urlencoded | Ignore the form data set and retrieve the file specified
by action.
| If the specified file is executable, launch the specified file in an environment that complies to the CGI Specification [CGI], using the encoded data set as the input, and the resulting standard output as the response body. | Use the encoded data set as the content of a file and
store it in the location specified by action. The response
body has no content (equivalent to an HTTP 204 No Content response.)
| Ignore the form data set and delete the file specified
by action. The response body has no content (equivalent to
an HTTP 204 No Content response.)
|
| multipart/form-data | ||||
| application/x-www-form+xml | ||||
| text/plain | ||||
| File upload | Handle as for other types except the encoded form data set is the contents of the specified file. | Store the selected file at the location specified by the
action URI.
|
mailto: actionsThe mailto: URI scheme is described by [RFC2368].
UAs should not send e-mails without the explicit consent of the user.
All submissions made using mailto: result in the equivalent
of an HTTP 204 No Content response. Thus the replace attribute is effectively ignored when
enctype is a mailto URI.
| get | post | put | delete | |
|---|---|---|---|---|
| application/x-www-form-urlencoded | Use the encoded data set as the headers part (see [RFC2368]) of a mailto: URI formed
from the action URI and process that URI.
| Use the encoded data set as the default message body,
with the Content-Type set appropriately, for a message
based on the specified action URI.
| Handle as if method was
post.
| |
| multipart/form-data | Handle as if enctype was
application/x-www-form-urlencoded.
| |||
| application/x-www-form+xml | ||||
| text/plain | ||||
| File upload | Attach the selected file to a message based on the specified
action URI.
| |||
smsto: and sms: actionsThe smsto: and sms: URI schemes are not yet
specified.
UAs should not send SMSes without the explicit consent of the user.
All submissions made using the smsto: and sms:
URI schemes result in the equivalent of an HTTP 204 No Content response.
Thus the replace attribute is
effectively ignored when enctype is an SMS URI.
| get | post | put | delete | |
|---|---|---|---|---|
| application/x-www-form-urlencoded | Behaviour
is undefined, pending the release of an smsto: or
sms: specification.
| Use the encoded data set as the default message body for a message
based on the specified action URI.
| Handle as if method was
post.
| |
| multipart/form-data | Handle as if enctype was
application/x-www-form-urlencoded.
| Handle as if enctype was
application/x-www-form-urlencoded.
| ||
| application/x-www-form+xml | ||||
| text/plain | Use the encoded data set as the default message body for a message
based on the specified action URI.
| |||
| File upload | Handle as if enctype was
application/x-www-form-urlencoded.
| |||
javascript: actionsThe javascript: URI scheme is described
by [CSJSR]. ECMAScript is defined in [ECMA262].
If the response body of a submission to a javascript:
action is the ECMAScript void type, then it is treated as if
it was an HTTP 204 Not Content response.
| get | post | put | delete | |
|---|---|---|---|---|
| application/x-www-form-urlencoded | Ignore the form data set and access the
action URI in the current context. The response body is
the return value of the script.
| Encode the form data set by putting each name/value pair into a newly created object using the names as attributes of that object and the values as the values of those attributes. Execute the URI in the context of the document after having added the aforementioned object to the start of the scope chain. Duplicate names should cause the property to become an array, with each value represented in the array. The response body is the return value of the script. | Handle as if method was
post.
| |
| multipart/form-data | ||||
| application/x-www-form+xml | ||||
| text/plain | ||||
| File upload | ||||
There are two scenarios where authors may wish data to be fetched from
an external file to fill forms. In the first, a select's
options are replaced by options from an external file. In the second, a
form's values are prefilled from an external data source.
In both cases, the prefilling may either be full, in which case the previous contents are removed first, or incremental, in which case the fetched data is in addition to the data already in the form.
Implementations may limit which hosts, ports, and schemes can be accessed using these methods. For example, HTTP-based content should not be able to pre-seed a form based on content from the local file system. Similarly, cross-domain scripting restrictions are fully expected to apply.
select elementsIf a select element being parsed has a data
attribute, then as soon as the select element and all its
children have been parsed and added to the document, it should be
prefilled.
If a select element has a data attribute, it
must be a URI that points to a well-formed XML file whose root element is
a select element in the
http://www.w3.org/1999/xhtml namespace. The MIME type must be
an XML MIME type [RFC3023], preferably
application/xml. It should not be
application/xhtml+xml since the root element is not
html.
UAs must process this file if it has an XML MIME type [RFC3023], if it is a well-formed XML file, and if the root element is the right root element in the right namespace. If any of these conditions are not met, UAs must act as if the attribute was not specified, although they may report the error to the user. UAs are expected to correctly handle namespaces, so the file may use prefixes, etc.
If the UA processes the file, it must use the following algorithm to fill the form.
type attribute with the
exact literal string incremental, the children of the
select element in the original document must all be removed
from the document.
select element in the
referenced document are imported into the original document and inserted
as children of the select element. (Even if importing into a
text/html document, the newly imported nodes will still be
namespaced.)
select are ignored, as are
attributes on the select.
If a select element has its data attribute
manipulated via the DOM, then that should immediately begin the prefilling
process too. However, any currently executing script must be guaranteed to
run to completion before the changes required by the process take effect.
If the process is started while an outstanding prefilling request is still
being attended to, the requests must all be serviced in the order they
were started.
The following script has only one possible valid outcome:
var select = document.createElementNS('http://www.w3.org/1999/xhtml', 'select');
select.data = 'data:application/xml,<select xmlns="http://www.w3.org/1999/xhtml" type="incremental"><option>b</option></select>';
select.data = select.data;
// at this point, select.length == 0 is guaranteed
var option = document.createElementNS('http://www.w3.org/1999/xhtml', 'option');
option.appendChild(document.createTextNode('a'));
select.appendChild(option);
// at this point, select.length == 1 is guaranteed
document.documentElement.appendChild(select);
...namely, the insertion at the end of the document of a select widget
which, in due course, will have three options, namely 'a', 'b' and 'b'.
Note that if the script was modified so tha the URI in the second line
did not say type="incremental", then the resulting select
widget would only have one option, the last 'b'.
Before load events are fired, but after
the entire document has been parsed and after select elements
have been filled from external data sources
(if necessary), forms with data attributes are prefilled.
In particuar, UAs should not specifically wait for images and stylesheets to be loaded before preseeding forms.
If a form has a data attribute, it must be a
URI that points to a well-formed XML file whose root element is a
formdata element in the data:,formData
namespace. The MIME type must be an XML MIME type [RFC3023], preferably
application/xml.
UAs must process this file if it has an XML MIME type [RFC3023], if it is a well-formed XML file, and if the root element is the right root element in the right namespace. If any of these conditions are not met, UAs must act as if the attribute was not specified, although they may report the error to the user. UAs are expected to correctly handle namespaces, so the file may use prefixes, etc.
If the UA processes the file, it must use the following algorithm to fill the form.
type attribute with the
exact literal string incremental, the form must be reset to
its initial values as specified in the markup.
repeat elements in the data:,formData
namespace that are children of the root element, have a non-empty
template attribute and an
index attribute that contains only one or more digits in the
range 0-9 with an optional leading minus sign, have no other
non-namespaced attributes, and have no content, must be processed as
follows:
If the template attribute
specifies an element that is not a repetition template, then the element is
ignored.
If the template attribute
specifies a repetition template
and that template already has a repetition
block with the index specified by the index
attribute, then the element is ignored.
Otherwise, the specified template's addRepetitionBlockByIndex()
method is called, with a null first argument and the index specified by
the repeat element's index attribute as the
second.
field elements in the data:,formData
namespace that are children of the root element, have a non-empty
name attribute and an index
attribute that contains only one or more digits in the range 0-9, have no
other non-namespaced attributes, and have either nothing or only text and
CDATA nodes as children, must be used to initialize fields, as follows.
First, the form control that the field references must be identified.
This is done by walking the list of form controls associated with the
form until one is found that has a name exactly equal to the name given
in the field element's name attribute, skipping as many such matches as
is specified in the index attribute.
If the identified form control is a file upload control, a push
button control, or an image control, then the field element
is now skipped.
Next, if the identified form control is not a multiple-valued control
(a multiple-valued control is one that can generate more than one value
on submission, such as a <select
multiple="multiple">), or if it is a multiple-valued control
but it is the first time the control has been identified by a
field element in this data file that was not ignored, then
it is set to the given value (the contents of the field
element), removing any previous values (even if these values were the
result of processing previous field elements in the same
data file). Otherwise, this is a
subsequent value for a
multiple-valued control, and the given value (the contents of the
field element) should be added to the list of
values that the element has selected.
If the element cannot be given the value specified, the
field element is ignored and the control's value is left
unchanged. For example, if a checkbox has its value attribute set to
green and the field element specifies that its
value should be set to blue, it won't be changed from its
current value. (The only values that would have an effect in this
example are "", which would uncheck the checkbox, and "green", which
would check the checkbox.) Another example would be a datetime control where the specified value
is outside the range allowed by the min
and max attributes. The format must
match the allowed formats for that type for the value to be set.
If the element is a multiple-valued control and the control already has the given value selected, but it can be given the value again, then that occurs. For example, in the following case:
<select name="select" multiple="multiple"> <option>test</option> <option>test</option> <option>test</option> </select>
...if the data file contained two instances of:
<field name="select" index="0">test</select>
...then the first two option elements would end up
selected, and the last would not. This would be the case irrespective of
which option elements had their selected
attribute set in the markup.
The option elements are never directly
matched by field elements; it is the select
element in this case that is matched (twice). This is why the two
field elements select subsequent values in the control.
If the element is a multiple-valued control and the control already has the given value selected and it cannot be given the value again, then the field is ignored.
formchange event is then
fired on all the form controls of the form.
Note that file upload controls cannot be repopulated.
However, output control can be populated. This can
be used, for example, for localizing a form by including the structure in
one file and the strings in another. (The semantics of this practice are
somewhat dubious, however. It is only mentioned because XForms advocates
claim this as a feature.)
Setting the data attribute dynamically does not cause the
UA to refill the form. The semantics of the data attribute
are only relevant during initial document load, with the form filling
kicked off just as the document has finished being parsed. Thus, forms
with data attributes that are added to the document by script
before the UA has finished parsing the document must be prefilled. The DOM
can be used to refill a form after the
document has finishing loading.
Unless otherwise specified, these interfaces have the same semantics as defined in [DOM2HTML].
interface HTMLFormElement : HTMLElement {
readonly attribute HTMLCollection elements;
readonly attribute long length;
attribute DOMString name;
attribute DOMString acceptCharset;
attribute DOMString action;
attribute DOMString enctype;
attribute DOMString method;
attribute DOMString target;
void submit();
void reset();
// new in this specification:
const unsigned short ERROR_TYPE_MISMATCH = 1;
const unsigned short ERROR_RANGE_UNDERFLOW = 2;
const unsigned short ERROR_RANGE_OVERFLOW = 4;
const unsigned short ERROR_PRECISION_EXCEEDED = 8;
const unsigned short ERROR_TOO_LONG = 16;
const unsigned short ERROR_PATTERN_MISMATCH = 32;
const unsigned short ERROR_REQUIRED = 64;
const unsigned short ERROR_USER_DEFINED = 32768;
attribute DOMString accept;
attribute DOMString replace;
readonly attribute HTMLCollection templateElements;
bool validate();
bool willConsiderForSubmission(in Element element);
void resetFromData(in Document data);
void dispatchFormInput();
void dispatchFormChange();
};
interface HTMLSelectElement : HTMLElement {
readonly attribute DOMString type;
attribute long selectedIndex;
attribute DOMString value;
attribute unsigned long length;
// raises(DOMException) on setting
readonly attribute HTMLFormElement form;
readonly attribute HTMLOptionsCollection options;
attribute boolean disabled;
attribute boolean multiple;
attribute DOMString name;
attribute long size;
attribute long tabIndex;
void add(in HTMLElement element,
in HTMLElement before)
raises(DOMException);
void remove(in long index);
void blur();
void focus();
// new in this specification:
attribute DOMString pattern;
attribute boolean required;
attribute boolean autocomplete;
attribute DOMString inputmode;
attribute long maxLength;
readonly attribute HTMLCollection selectedOptions;
readonly attribute HTMLCollection labels;
readonly attribute boolean successful;
readonly attribute long validity;
bool validate();
void setValidity(in boolean valid);
void changed();
void formchanged();
};
interface HTMLOptGroupElement : HTMLElement {
attribute boolean disabled;
attribute DOMString label;
};
interface HTMLOptionElement : HTMLElement {
readonly attribute HTMLFormElement form;
attribute boolean defaultSelected;
readonly attribute DOMString text;
readonly attribute long index;
attribute boolean disabled;
attribute DOMString label;
attribute boolean selected;
attribute DOMString value;
};
interface HTMLInputElement : HTMLElement {
attribute DOMString defaultValue;
attribute boolean defaultChecked;
readonly attribute HTMLFormElement form;
attribute DOMString accept;
attribute DOMString accessKey;
attribute DOMString align;
attribute DOMString alt;
attribute boolean checked;
attribute boolean disabled;
attribute long maxLength;
attribute DOMString name;
attribute boolean readOnly;
attribute unsigned long size;
attribute DOMString src;
attribute long tabIndex;
attribute DOMString type;
attribute DOMString useMap;
attribute DOMString value;
void blur();
void focus();
void select();
void click();
// new in this specification:
attribute DOMString min;
attribute DOMString max;
attribute DOMString pattern;
attribute boolean required;
attribute boolean autocomplete;
attribute DOMString inputmode;
readonly attribute RepetitionElement template;
readonly attribute HTMLCollection labels;
attribute DOMString action;
attribute DOMString enctype;
attribute DOMString method;
attribute DOMString replace;
readonly attribute boolean successful;
readonly attribute long validity;
bool validate();
void setValidity(in boolean valid);
void changed();
void formchanged();
};
interface HTMLTextAreaElement : HTMLElement {
attribute DOMString defaultValue;
readonly attribute HTMLFormElement form;
attribute DOMString accessKey;
attribute long cols;
attribute boolean disabled;
attribute DOMString name;
attribute boolean readOnly;
attribute long rows;
attribute long tabIndex;
readonly attribute DOMString type;
attribute DOMString value;
void blur();
void focus();
void select();
// new in this specification:
attribute DOMString wrap;
attribute DOMString pattern;
attribute boolean required;
attribute boolean autocomplete;
attribute DOMString inputmode;
attribute long maxLength;
readonly attribute HTMLCollection labels;
readonly attribute boolean successful;
readonly attribute long validity;
bool validate();
void setValidity(in boolean valid);
void changed();
void formchanged();
};
interface HTMLButtonElement : HTMLElement {
readonly attribute HTMLFormElement form;
attribute DOMString accessKey;
attribute boolean disabled;
attribute DOMString name;
attribute long tabIndex;
attribute DOMString value;
// modified in this specification
attribute DOMString type;
// new in this specification:
attribute DOMString action;
attribute DOMString enctype;
attribute DOMString method;
attribute DOMString replace;
readonly attribute HTMLCollection labels;
readonly attribute RepetitionElement template;
};
interface HTMLLabelElement : HTMLElement {
readonly attribute HTMLFormElement form;
attribute DOMString accessKey;
attribute DOMString htmlFor;
// new in this specification:
readonly attribute Element control;
};
interface HTMLFieldSetElement : HTMLElement {
readonly attribute HTMLFormElement form;
// new in this specification
attribute boolean disabled;
};
interface HTMLLegendElement : HTMLElement {
readonly attribute HTMLFormElement form;
attribute DOMString accessKey;
attribute DOMString align;
};
// new in this specification
interface HTMLOutputElement : HTMLElement {
attribute DOMString defaultValue;
readonly attribute HTMLFormElement form;
attribute DOMString name;
attribute DOMString value;
};
// new in this specification
interface RepetitionElement {
const unsigned short REPETITION_NONE = 0;
const unsigned short REPETITION_TEMPLATE = 1;
const unsigned short REPETITION_BLOCK = 2;
attribute unsigned short repetitionType;
attribute long repetitionIndex;
readonly attribute Element repetitionTemplate;
readonly attribute HTMLCollection repetitionBlocks;
void addRepetitionBlock(in Node refNode);
void addRepetitionBlockByIndex(in Node refNode, in long index);
void moveRepetitionBlock(in long distance);
void removeRepetitionBlock();
}
// new in this specification
interface FormImplementation {
Document load(in DOMString action,
in EventListener load, in EventListener error);
Document loadWithBody(in DOMString action, in DOMString method,
in DOMString enctype, in DOMString content,
in EventListener load, in EventListener error);
Document loadWithDocument(in DOMString action, in DOMString method,
in Document document,
in EventListener load,
in EventListener error);
}
HTMLFormElement interfaceThe new accept attribute reflects the
form element's accept
attribute and its addition here merely addresses an oversight in DOM2.
The elements array is defined to not include image controls
(input elements of type image). This is for backwards compatibility with
DOM Level 0. This excludes image buttons from several features of this
specification, such as onformchange processing and
validation.
The templateElements attribute contains the list of form
controls associated with this form that form part of repetition templates
that the form itself is not also a part of. It is defined in more detail
in the section on the repetition model.
(Image controls are part of this array, when appropriate.)
The form.validate() method
invokes the validate() method of all
the elements in the form's elements list whose interfaces
have a validate() method defined and
a successful attribute defined and
whose successful attribute has the
true value, and returns the logical-and of all the return values (i.e. it
returns false if any of the form controls are successful but invalid).
The willConsiderForSubmission()
must return true if the element passed as an argument is in the form's
elements array, and is of a type that can be involved in
submission. (For example, a text field or radio button control, but not a
button of type button or a fieldset.) It must also return
true for image buttons associated with the form that are not in the
templateElements list. For all other element it must return
false.
The following event handler checks to see if the event target is a control that will be considered for submission.
function focussed(event) {
if (event.target.form instanceof HTMLFormElement &&
event.target.form.willConsiderForSubmission(event.target)) {
// event.target is a form control that could be submitted
}
}
The reset() method resets the form, then fires a a formchange event on all the form controls of
the form.
The resetFromData() method takes one
argument, a document to use for resetting the form. If this argument is
null, the method does nothing. Otherwise, the algorithm described in the
section on seeding a form with initial values must
be run with the given document instead of the document mentioned in the
data attribute.
The dispatchFormChange()
and dispatchFormInput()
methods cause formchange and
forminput events (respectively) to
be fired to all the controls in the elements array, much like
happens for the default action of change and
input events.
In the ECMAScript binding, objects that implement the
HTMLFormElement interface reflect their elements
according to the following semantics:
If a name is used by more than one control, the form object has a
property of that name that references a NodeList interface
that lists the controls of that name.
If a name is used by exactly one control, the form object has a property of that name that references that control.
HTMLSelectElement interfaceThe selectedOptions
attribute provides a readonly list of the descendant
HTMLOptionElement nodes that currently have their
selected attribute set to a true value (a subset of the
controls listed in the options attribute). The list is
returned live, so changing the options selected (by the user or by script)
will change the list. The order of the list should be consistent with the
order of the options list.
HTMLCollection interfaceThis specification does not change the HTMLCollection
interface's definition from its DOM2 HTML definition, but does slightly
amend its ECMAScript binding.
For the ECMAScript binding, when namedItem() would match
more than one node, instead of returning an arbitrary node from the
collection, it must return a NodeList giving all the nodes
that would match, in document order.
This intentionally matches what existing implementations have done. User agents have found that supporting the DOM2 definition strictly is not possible without sacrificing compatibility with existing content.
HTMLOutputElement interfaceThis interface is added for the new output element. Its
attributes work analogously to those on other controls. The semantics of
the value and defaultValue DOM attributes are
described in the section describing the output element.
The successful attribute
returns whether or not the form control is successful. Only successful controls are included
when a form is submitted.
The validity attribute returns
whether the form control is currently valid. Its value is a bit field
giving the errors that currently apply ot the control, and must be equal
to the sum of the relevant ERROR_* constants defined on the
HTMLFormElement interface. These have the following meanings:
expdate fields, and the user has entered
SEP02, then this error code would be used. This code is also
used when the selected file in a file upload control does not have an
appropriate MIME type. If the control is empty, this flag will not be
set.
min attribute is lower than the minimum, or a file
upload control has fewer files selected than the minimum. If the control
is empty, this flag will not be set.
max attribute is higher than the maximum, or a
file upload control has more files selected than the maximum. If the
control is empty, this flag will not be set.
maxlength attribute is longer than the
attribute allows.
pattern attribute doesn't match the pattern.
If the control is empty, this flag will not be set.
required
attribute set but has no value.
setValidity() method.
When the definitions above refer to elements that have an attribute set
on them, they do not refer to elements on which that attribute is defined
not to apply. For example, the ERROR_REQUIRED code cannot be
set on an <input type="checkbox"> element, even if that
element has the required attribute
set, since required doesn't apply to
check boxes.
The validate() method, present on
several of the form control interfaces, causes an invalid event to be fired on that control,
unless the validity of the control is
zero. It returns true if the validity
of the control is zero, otherwise it returns false. Recall that this is automatically done during form submission.
The setValidity() method sets and resets
the ERROR_USER_DEFINED bit on the validity attribute based on the method's
argument. If the argument is false, the bit is set (indicating that the
control is not valid), and if the argument is true, the bit is reset (the
control is valid). Even attributes that are empty and not required can be
marked invalid like this, and would abort form submission if so marked.
Setting this bit is persistent, in that the bit remains set until
specifically unset using the same method. For instance resetting the form,
changing the control value, or moving the element around the document do
not affect the value of this bit.
The new pattern, required, autocomplete, inputmode, min, max, wrap, disabled, action,
enctype, method and replace attributes simply reflect the current
value of their relevant content attribute.
The type attribute on the HTMLButtonElement
interface is changed from read-only to read-write.
The form attribute on most of the control interfaces is
read-only, but reflects the curret state of the form content
attribute. If the content attribute is changed, e.g. via the
setAttribute() method, the DOM attribute should change with
it.
Form controls all have a labels DOM
attribute that lists all the label elements that refer to the
control (either through the for attribute or via
containership), in document order.
Similarly, HTMLLabelElements have a control DOM attribute that points to the
associated element node, if any.
A label must be listed in the labels
list of the control to which its control attribute points, and no other.
The changed() and formchanged() methods cause
change and formchange
events to be fired on the element. They are intended primarily to be used
from oninput and onforminput handlers to avoid
code duplication:
<input oninput="changed" onchange="some long algorithm">
The RepetitionElement
interface must be implemented by all elements.
If the element is a repetition
template, its repetitionType DOM attribute must
return REPETITION_TEMPLATE.
Otherwise, if the element is a repetition
block, it must return REPETITION_BLOCK. Otherwise,
it is a normal element, and that attribute should return
REPETITION_NONE.
Setting repetitionType
modifies the repeat
attribute. The repeat attribute's namespace
depends on the element node's namespace; if the element is in the
http://www.w3.org/1999/xhtml namespace then the attribute has
no namespace, otherwise the attribute is in that namespace. If
repetitionType is set to
REPETITION_NONE, the attribute is removed. If it is set to
REPETITION_TEMPLATE, the
attribute is set to "template". If
repetitionType is set to
REPETITION_BLOCK, the repeat content attribute
is set to the value of the repetitionIndex DOM attribute.
The repetitionIndex
attribute must return the current value of the index of the repetition
template or block. If the element is a repetition block, setting this
attribute must update the repeat attribute appropriately (and
changing the attribute directly must affect the value of the repetitionIndex attribute). Otherwise,
if the element is a repetition template, setting this attribute changes
the template's index but does not affect any other aspect of the DOM. If
the element is a normal element, it must always return zero, and setting
the attribute must have no effect.
The repetitionTemplate
attribute is null unless the element is a repetition block, in which case
it points to the block's template. If the block is an orphan
repetition block then it returns null.
The repetitionBlocks
attribute is null unless the element is a repetition template, in which
case it points to a list of elements (an HTMLCollection,
although the name of that interface is a misnomer since there is nothing
HTML-specific about it). The list consists of all the repetition
blocks that have this element as their template. The list is live.
The addRepetitionBlock(),
addRepetitionBlockByIndex(),
moveRepetitionBlock() and
removeRepetitionBlock()
methods are defined in the section on the
repetition model.
The template DOM attribute on the
HTMLInputElement and HTMLButtonElement
interfaces represents the repetition template that the template content attribute refers to. If the
content attribute points to a non-existent element or an element that is
not a repetition template, the DOM attribute returns null. This DOM
attribute is readonly in this version of this specification.
The FormImplementation interface can be obtained using
binding-specific casting methods on the implementation
object.
The load() method on the
FormImplementation interface returns a Document
interface, and then queues the specified resource to be loaded into that
document. When the document has finished loading, a load event fires on the object. If a failure
occurs during loading, an error event fires instead. The
load and error arguments to
the load method can be used to specify
event handlers for those events.
The loadWithBody() method is
analogous, but allows the author to specify the entity body of the request
as a string (e.g. for scripted HTTP POST requests).
The loadWithDocument()
method is analogous, but allows the author to specify the entity body of
the request as a Document object.
The arguments for these methods have the following meanings:
TYPE_MISMATCH_ERR exception is raised.
post is assumed.
application/x-www-form-urlencoded for loadWithBody and
application/xml for loadWithDocument.
TYPE_MISMATCH_ERR exception is raised.
TYPE_MISMATCH_ERR exception is raised.
{"http://www.w3.org/2001/xml-events", "load"} event. If a
null value is passed, no handler is attached.
{"http://www.w3.org/2001/xml-events", "error"} event. If a
null value is passed, no handler is attached.
Implementations may limit which hosts, ports, and schemes can be accessed using this method. For example, it is highly recommended that the SMTP port not be allowed, since otherwise it can be used to relay spam on the behalf of the unwitting user. Similarly, cross-domain scripting restrictions are fully expected to apply.
These methods are asynchronous, and are guaranteed to not finish loading
the document or signal an error before the running script either completes
or yields to the user (e.g. by calling window.alert()). Thus,
the following code is guaranteed to hook in the event handlers before the
document has either finished loading or signalled an error:
var d = document.implementation.loadWithBody('http://example.org/search',
'post', 'application/xml', '<search keywords="test search"/>');
d.addEventListenerNS('http://www.w3.org/2001/xml-events', 'load',
function () { alert('loaded!'); },
false, null);
d.addEventListenerNS('http://www.w3.org/2001/xml-events', 'error',
function () { alert('failed!'); },
false, null);
The following code is equivalent:
document.implementation.loadWithBody('http://example.org/search', null,
'application/xml', '<search keywords="test search"/>',
function () { alert('loaded!'); },
function () { alert('failed!'); });
The loadWithDocument()
method serialises its document node and uses the
application/xml MIME type. It is otherwise identical to the
loadWithBody() method. If the
serialising fails, the method will raise an INVALID_STATE_ERR
exception.
All other errors will simply generate error events on the
returned document object.
The semantics of loading documents using these methods are described in
the section on the semantics of
method and enctype attributes.
Document loads queued using these methods, and the subsequent firings of load or error events, must occur whether or not the documents go out of scope of the calling script.
For more control over loading remote documents, see DOM3 Load and Save [DOM3LS].
The CSS working group is expected to develop a language designed, amongst other things, for the advanced styling of form controls. In the meantime, technologies such as [HTC] and [XBL] can be used as guides for what is expected.
UAs, in the absence of such advanced styling information, may render form controls described in this draft as they wish. It is recommended that form controls remain faithful to the look and feel of the system's global user interface, though.
Note that [CSS21] explicitly does not define how CSS applies to form controls.
[CSS3UI] introduces a number of pseudo-classes for form controls. Their relationship to the form controls described in this specification is described here.
disabled attribute set.
disabled attribute set.
checked.
invalid event fired at them if the form was
submitted.
invalid event fired at them if the form was
submitted.
required attribute set.
required attribute set.
readonly attribute set.
readonly attribute set (including password fields, although technically they
should be called "writeonly").
When the definitions above refer to elements that have an attribute set
on them, they do not refer to elements on which that attribute is defined
not to apply. For example, the :read-only attribute cannot
apply to a <input type="radio"> element, even if that
element has the readonly attribute
set, since readonly doesn't apply to
radio buttons.
The Forms Extensions Module provides all of the forms features found in HTML 4.0, plus the extensions described above. Specifically, the Forms Extensions Module supports:
| Elements | Attributes | Minimal Content Model |
|---|---|---|
| form | Common, accept (ContentTypes), accept-charset (Charsets), action (URI), enctype (ContentType), method ("get"* | "post" | "put" | "delete"), replace ("document"* | "values") | (Heading | List | Block)* |
| input | Common, accept (ContentTypes), accesskey (Character), action (URI), alt (Text), autocomplete ("on"* | "off"), checked ("checked"), disabled ("disabled"), enctype (ContentType), form (IDREF), help (URI), inputmode (CDATA), maxlength (Number), method ("get" | "post" | "put" | "delete"), min (CDATA), max (CDATA), name (CDATA), pattern (CDATA), precision (CDATA), readonly ("readonly"), replace ("document" | "values") required ("required"), size (Number), src (URI), tabindex (Number), template (IDREF), type ("text"* | "password" | "checkbox" | "radio" | "button" | "submit" | "reset" | "add" | "remove" | "file" | "hidden" | "image" | "datetime" | "date" | "expdate" | "week" | "time" | "number" | "email" | "tel" | "uri"), value (CDATA), | EMPTY |
| select | Common, autocomplete ("on"* | "off"), disabled ("disabled"), form (IDREF), help (URI), inputmode (CDATA), maxlength (Number), multiple ("multiple"), name (CDATA), pattern (CDATA), required ("required"), size (Number), tabindex (Number) | (optgroup | option)* |
| optgroup | Common, disabled ("disabled"), label* (Text) | option* |
| option | Common, disabled ("disabled"), label (Text), selected ("selected"), value (CDATA) | PCDATA |
| textarea | Common, accesskey (Character), autocomplete ("on"* | "off"), cols (Number), disabled ("disabled"), form (IDREF), help (URI), inputmode (CDATA), maxlength (Number), name (CDATA), readonly ("readonly"), required ("required"), rows (Number), tabindex (Number), wrap ("soft"* | "hard") | PCDATA |
| output | Common, form (IDREF), name (CDATA) | PCDATA |
| button | Common, accesskey (Character), action (URI), disabled ("disabled"), enctype (ContentType), form (IDREF), help (URI), method ("get" | "post" | "put" | "delete"), name (CDATA), replace ("document" | "values") tabindex (Number), template (IDREF), type ("button" | "submit"* | "reset" | "add" | "remove"), value (CDATA) | (PCDATA | Heading | List | Block - Form | Inline - Formctrl)* |
| fieldset | Common, disabled ("disabled"), form (IDREF), help (URI), | (PCDATA | legend | Flow)* |
| legend | Common, accesskey (Character) | (PCDATA | Inline)* |
| label | Common, accesskey (Character), for (IDREF) | (PCDATA | Inline - label)* |
This module defines two content sets:
When this module is used, it adds the Form content set to
the Block content set and it adds the Formctrl
content set to the Inline content set as these are defined in
the Text Module.
All XHTML elements (all elements in the
http://www.w3.org/1999/xhtml namespace) may have the repeat attribute specified.
Similarly, the global attribute repeat in the
http://www.w3.org/1999/xhtml namespace may be specified on
any non-XHTML element. These two attributes may either have the value
"template" or be an integer (an
optional '-' character followed by one or more decimal digits).
The form element may be placed inside XHTML
head elements when it is empty.
The repeat element in
the XHTML namespace is allowed anywhere. It is only allowed to have one
attribute, index, whose value must be an integer (an optional
'-' character followed by one or more decimal digits).
Warning. Documents using the new repetition model with the index substitution feature on ID attributes cannot validate, as the "[" and "]" characters are not valid in IDs.
The oninput attribute is added to all the elements that
have an onchange attribute in the XHTML Intrinsic Events
module. The onformchange, onforminput and
oninvalid attributes are added to all form control elements
(including fieldset).
When frames are also allowed, the target attribute is added
to the input and button elements.
The Forms Extensions Module is a superset of the Forms and Basic Forms
modules. These modules may not be used together in a single document type.
Note that the content models in this module differ from those of the
XHTML1 Forms module in some subtle ways (for example, the
select element may be empty).
The input element takes a large number of attributes that
do not always apply. The following table summarizes which attributes apply
to which input types.
type
| text
| password
| checkbox
| radio
| button
| submit
| reset
| add
| remove move-up move-down
| file
| hidden
| image
| datetime date expdate week time
| number
| email tel uri
|
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| accept | - | - | - | - | - | - | - | - | - | Yes | - | - | - | - | - |
| accesskey | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | - | Yes | Yes | Yes | Yes |
| action | - | - | - | - | - | Yes | - | - | - | - | - | Yes | - | - | - |
| alt | - | - | - | - | - | - | - | - | - | - | - | Yes | - | - | - |
| autocomplete | Yes | Yes | Yes | Yes | - | - | - | - | - | Yes | - | - | Yes | Yes | Yes |
| checked | - | - | Yes | Yes | - | - | - | - | - | - | - | - | - | - | - |
| disabled | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| enctype | - | - | - | - | - | Yes | - | - | - | - | - | Yes | - | - | - |
| form | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| help | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | - | Yes | Yes | Yes | Yes |
| inputmode | Yes | Yes | - | - | - | - | - | - | - | - | - | - | - | - | Yes |
| maxlength | Yes | Yes | - | - | - | - | - | - | - | Yes | - | - | - | - | - |
| method | - | - | - | - | - | Yes | - | - | - | - | - | Yes | - | - | - |
| min | - | - | - | - | - | - | - | - | - | Yes | - | - | Yes | Yes | - |
| max | - | - | - | - | - | - | - | - | - | Yes | - | - | Yes | Yes | - |
| name | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| pattern | Yes | Yes | - | - | - | - | - | - | - | - | - | - | - | - | Yes |
| precision | - | - | - | - | - | - | - | - | - | - | - | - | - | Yes | - |
| readonly | Yes | Yes | - | - | - | - | - | - | - | - | - | - | Yes | Yes | Yes |
| replace | - | - | - | - | - | Yes | - | - | - | - | - | Yes | - | - | - |
| required | Yes | Yes | - | Yes | - | - | - | - | - | Yes | - | - | Yes | Yes | Yes |
| size | Yes | Yes | - | - | - | - | - | - | - | - | - | - | - | - | - |
| src | - | - | - | - | - | - | - | - | - | - | - | Yes | - | - | - |
| tabindex | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | - | Yes | Yes | Yes | Yes |
| target | - | - | - | - | - | Yes | - | - | - | - | - | Yes | - | - | - |
| template | - | - | - | - | - | - | - | Yes | - | - | - | - | - | - | - |
| value | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | - | Yes | - | Yes | Yes | Yes |
Thanks to Håkon Wium Lie, Malcolm Rowe, Maciej Stachowiak, David Hyatt, Peter N Stark, Christopher Aillon, Jason Kersey, Neil Rashbrook, Brendan Eich, Bert Bos, Jukka K. Korpela, Sebastian Schnitzenbaumer, Daniel Bratell, Jens Lindström, Daniel Brooks, Christian Schmidt, Olli Pettay, Andy Heydon, Susan Borgrink, Martin Honnen, Jonas Sicking, Simon Montagu, Christian Biesinger, David Matja, and John Keiser for their substantial comments.
Thanks also to Rich Doughty, Anne van Kesteren, Alexander J. Vincent, David E. Cleary, Martijn Wargers, Matthew Mastracci, Mark Birbeck, Michael Daskalov, Subramanian Peruvemba, Peter Stark, Shanti Rao, Martin Kutschker, and Rigo Wenning for their comments, to the Slashdot community for some ideas, and to the #mozilla crew, the #opera crew, and the #mrt crew for their ideas and support.
Thanks to the XForms working group for unintentionally giving the incentive to develop this specification.