HTML5
A vocabulary and associated APIs for HTML and XHTML
This is revision 1.5612.
This is revision 1.5612.
The name content
attribute gives the name of the form control, as used in form
submission and in the form element's elements object. If the attribute
is specified, its value must not be the empty string.
Any non-empty value for name
is allowed, but the names "_charset_" and "isindex" are special:
isindexThis value, if used as the name of a Text control that is the first
control in a form that is submitted using the application/x-www-form-urlencoded
mechanism, causes the submission to only include the value of this
control, with no name.
_charset_This value, if used as the name of a Hidden control with no value attribute, is automatically
given a value during submission consisting of the submission
character encoding.
The disabled
content attribute is a boolean attribute.
A form control is disabled
if its disabled attribute is
set, or if it is a descendant of a fieldset element
whose disabled attribute
is set and is not a descendant of that
fieldset element's first legend element
child, if any.
A form control that is disabled must prevent any click events that are queued on the user interaction task
source from being dispatched on the element.
Constraint validation: If an element is disabled, it is barred from constraint validation.
The disabled IDL
attribute must reflect the disabled content attribute.
Form controls have a value
and a checkedness. (The latter
is only used by input elements.) These are used to
describe how the user interacts with the control.
To define the behaviour of constraint validation in the face of
the input element's multiple attribute,
input elements can also have separately defined values.
The autofocus
content attribute allows the author to indicate that a control is to
be focused as soon as the page is loaded, allowing the user to just
start typing without having to manually focus the main control.
The autofocus attribute is
a boolean attribute.
There must not be more than one element in the document with the
autofocus attribute
specified.
When an element with the autofocus attribute specified is
inserted into a
document, user agents should run the following steps:
Let target be the element's
Document.
If target has no browsing context, abort these steps.
If target's browsing context has no top-level browsing context (e.g. it is a nested browsing context with no parent browsing context), abort these steps.
If target's browsing context had the sandboxed automatic features browsing context flag set when target was created, abort these steps.
If target's origin is not
the same as the
origin of the Document of the currently
focused element in target's top-level
browsing context, abort these steps.
If target's origin is not the same as the origin of the active document of target's top-level browsing context, abort these steps.
If the user agent has already reached the last step of this
list of steps in response to an element being inserted into a
Document whose top-level browsing
context's active document is the same as target's top-level browsing context's
active document, abort these steps.
If the user has indicated (for example, by starting to type in a form control) that he does not wish focus to be changed, then optionally abort these steps.
Queue a task that checks to see if the element is focusable, and if so, runs the focusing steps for that element. User agents may also change the scrolling position of the document, or perform some other action that brings the element to the user's attention. The task source for this task is the DOM manipulation task source.
Focusing the control does not imply that the user agent must focus the browser window if it has lost focus.
The autofocus
IDL attribute must reflect the content attribute of the
same name.
In the following snippet, the text control would be focused when the document was loaded.
<input maxlength="256" name="q" value="" autofocus> <input type="submit" value="Search">
A form control maxlength attribute, controlled by a dirty value flag, declares a limit on the number of
characters a user can input.
If an element has its form
control maxlength attribute specified,
the attribute's value must be a valid non-negative
integer. If the attribute is specified and applying the
rules for parsing non-negative integers to its value
results in a number, then that number is the element's maximum
allowed value length. If the attribute is omitted or parsing
its value results in an error, then there is no maximum
allowed value length.
Constraint validation: If an element has a maximum allowed value length, its dirty value flag is true, its value was last changed by a user edit (as opposed to a change made by a script), and the code-point length of the element's value is greater than the element's maximum allowed value length, then the element is suffering from being too long.
User agents may prevent the user from causing the element's value to be set to a value whose code-point length is greater than the element's maximum allowed value length.
Attributes for form submission can be specified both
on form elements and on submit buttons (elements that
represent buttons that submit forms, e.g. an input
element whose type attribute is
in the Submit Button
state).
The attributes for form submission that may be
specified on form elements are action, enctype, method, novalidate, and target.
The corresponding attributes for form submission
that may be specified on submit
buttons are formaction, formenctype, formmethod, formnovalidate, and formtarget. When omitted, they
default to the values given on the corresponding attributes on the
form element.
The action and
formaction
content attributes, if specified, must have a value that is a
valid non-empty URL potentially surrounded by
spaces.
The action of an element is
the value of the element's formaction attribute, if the
element is a submit
button and has such an attribute, or the value of its
form owner's action
attribute, if it has one, or else the empty string.
The method and
formmethod
content attributes are enumerated
attributes with the following keywords and states:
get, mapping
to the state GET, indicating
the HTTP GET method.post, mapping
to the state POST, indicating
the HTTP POST method.The missing value default for these attributes is the GET state.
The method of an element is
one of those states. If the element is a submit button and has a formmethod attribute, then the
element's method is that
attribute's state; otherwise, it is the form owner's
method attribute's state.
The enctype and
formenctype
content attributes are enumerated
attributes with the following keywords and states:
application/x-www-form-urlencoded" keyword and corresponding state.multipart/form-data" keyword and corresponding state.text/plain" keyword and corresponding state.The missing value default for these attributes is the
application/x-www-form-urlencoded
state.
The enctype of an element
is one of those three states. If the element is a submit button and has a formenctype attribute, then the
element's enctype is that
attribute's state; otherwise, it is the form owner's
enctype attribute's state.
The target and
formtarget
content attributes, if specified, must have values that are valid browsing
context names or keywords.
The target of an element is
the value of the element's formtarget attribute, if the
element is a submit
button and has such an attribute; or the value of its
form owner's target
attribute, if it has such an attribute; or, if the
Document contains a base element with a
target attribute, then the
value of the target attribute
of the first such base element; or, if there is no such
element, the empty string.
The novalidate
and formnovalidate
content attributes are boolean
attributes. If present, they indicate that the form is not to
be validated during submission.
The no-validate state of
an element is true if the element is a submit button and the element's
formnovalidate attribute
is present, or if the element's form owner's novalidate attribute is present,
and false otherwise.
This attribute is useful to include "save" buttons on forms that have validation constraints, to allow users to save their progress even though they haven't fully entered the data in the form. The following example shows a simple form that has two required fields. There are three buttons: one to submit the form, which requires both fields to be filled in; one to save the form so that the user can come back and fill it in later; and one to cancel the form altogether.
<form action="editor.cgi" method="post"> <p><label>Name: <input required name=fn></label></p> <p><label>Essay: <textarea required name=essay></textarea></label></p> <p><input type=submit name=submit value="Submit essay"></p> <p><input type=submit formnovalidate name=save value="Save essay"></p> <p><input type=submit formnovalidate name=cancel value="Cancel"></p> </form>
The action IDL
attribute must reflect the content attribute of the
same name, except that on getting, when the content attribute is
missing or its value is the empty string, the document's
address must be returned instead. The target IDL attribute must
reflect the content attribute of the same name. The
method and enctype IDL attributes
must reflect the respective content attributes of the
same name, limited to only known values. The encoding IDL attribute
must reflect the enctype content attribute,
limited to only known values. The noValidate IDL
attribute must reflect the novalidate content attribute. The
formAction IDL
attribute must reflect the formaction content attribute,
except that on getting, when the content attribute is missing or its
value is the empty string, the document's address must
be returned instead. The formEnctype IDL
attribute must reflect the formenctype content attribute,
limited to only known values. The formMethod IDL
attribute must reflect the formmethod content attribute,
limited to only known values. The formNoValidate IDL
attribute must reflect the formnovalidate content
attribute. The formTarget IDL
attribute must reflect the formtarget content attribute.
A form control dirname attribute
on a form control element enables the submission of the
directionality of the element, and gives the name of the
field that contains this value during form submission.
If such an attribute is specified, its value must not be the empty
string.