HTML and CSS Reference
In-Depth Information
Element-Specific Attributes
accept-charset
This attribute specifies the list of character encodings for input data that
must be accepted by the server processing the form. The value is a space- or comma-
delimited list of character sets as defined in RFC 2045. The default value for this attribute is
the reserved value
unknown
.
action
This attribute contains the URL of the server program that will process the contents
of the form. Some browsers also might support a
mailto
URL, which can mail the results to
the specified address. Otherwise, the delivery of the data in the form is defined by the
method
attribute.
autocomplete
This Microsoft proprietary attribute, introduced in Internet Explorer 5.0 and
redefined under HTML5, will automatically finish filling in information that the user has
previously input into an input field. Auto-filled information will likely be stored locally on
the end-user's system by some program, typically the browser itself.
enctype
This attribute indicates how form data should be encoded before being sent to the
server. The default is
application/x-www-form-urlencoded
. This encoding replaces
blank characters in the data with a plus character (
+
) and all other nonprinting characters
with a percent sign (
%
) followed by the character's ASCII HEX representation. The
multipart/form-data
option does not perform character conversion and transfers the
information as a compound MIME document. This must be used when using
<input
type="file">
. It also might be possible to use another encoding, such as
text/plain
with a mailed form, but in general you should be cautious about changing the
enctype
.
method
This attribute indicates how form information should be transferred to the server
using a particular HTTP method. A
get
value in the attribute indicates that form data
should be appended to the URL specified by the
action
attribute, thus creating a query
string. This approach is quite simple but imposes a size limitation that is difficult to gauge
(may be as low as 2 kilobytes in real situations). A value of
post
for this attribute transfers
the data of the form in the message body using the HTTP
POST
method which imposes no
data size limitation. Browsers may allow for other HTTP methods like
delete
or
put
as
suggested by the HTML5 specification, but so far such usage is rare. The
POST
method must
be used when file attachments are used in a form.
name
This attribute specifies a name for the form and was traditionally used by JavaScript
or other client-side programming technologies to reference forms and their contained
elements. Since HTML 4, the core
id
attribute can be used instead with DOM methods such
as
document.getElementById()
.
novalidate
This HTML5 Boolean attribute determines whether or not form validation
should be applied on the elements within. By default, validation is enforced unless
overridden by this attribute on the form level or a
formnovalidate
attribute is found on a
form element.
target
In documents containing frames, this attribute specifies the target frame that will
display the results of a form submission. In addition to named frames, several special
values exist. The
_blank
value indicates a new window. The
_parent
value indicates
