Web Forms 2.0 is an extension to the forms features found in HTML4.
Form elements and attributes in HTML5 provide a greater degree of
semantic mark-up than HTML4 and remove a great deal of the need for
tedious scripting and styling that was required in HTML4.
The <input> element in HTML4
HTML4 input elements use the
type attribute to specify the data type.HTML4 provides following types:
Type |
Description |
text | A free-form text field, nominally free of line breaks. |
password | A free-form text field for sensitive information, nominally free of line breaks. |
checkbox | A set of zero or more values from a predefined list. |
radio | An enumerated value. |
submit | A free form of button initiates form submission. |
file | An arbitrary file with a MIME type and optionally a file name. |
image | A coordinate, relative to a particular image's
size, with the extra semantic that it must be the last value selected
and initiates form submission. |
hidden | An arbitrary string that is not normally displayed to the user. |
select | An enumerated value, much like the radio type. |
textarea | A free-form text field, nominally with no line break restrictions. |
button | A free form of button which can initiates any event related to button. |
Following is the simple example of using labels, radio buttons, and submit buttons:
...
<form action="http://example.com/cgiscript.pl" method="post">
<p>
<label for="firstname">first name: </label>
<input type="text" id="firstname"><br />
<label for="lastname">last name: </label>
<input type="text" id="lastname"><br />
<label for="email">email: </label>
<input type="text" id="email"><br>
<input type="radio" name="sex" value="male"> Male<br>
<input type="radio" name="sex" value="female"> Female<br>
<input type="submit" value="send"> <input type="reset">
</p>
</form>
...
|
The <input> element in HTML5
Apart from the above mentioned attributes, HTML5 input elements introduced sevral new values for the
type attribute. These are listed below.
NOTE: Try all the following example using latest version of
Opera browser.
Type |
Description |
datetime | A
date and time (year, month, day, hour, minute, second, fractions of a
second) encoded according to ISO 8601 with the time zone set to UTC. |
datetime-local | A
date and time (year, month, day, hour, minute, second, fractions of a
second) encoded according to ISO 8601, with no time zone information. |
date | A date (year, month, day) encoded according to ISO 8601. |
month | A date consisting of a year and a month encoded according to ISO 8601. |
week | A date consisting of a year and a week number encoded according to ISO 8601. |
time | A time (hour, minute, seconds, fractional seconds) encoded according to ISO 8601. |
number | This accepts only numerical value. The step attribute specifies the precision, defaulting to 1. |
range | The range type is used for input fields that should contain a value from a range of numbers. |
email | This
accepts only email value. This type is used for input fields that
should contain an e-mail address. If you try to submit a simple text, it
forces to enter only email address in email@example.com format. |
url | This
accepts only URL value. This type is used for input fields that should
contain a URL address. If you try to submit a simple text, it forces to
enter only URL address either in http://www.example.com format or in
http://example.com format. |
The <output> element
HTML5 introduced a new element <output> which is used to
represent the result of different types of output, such as output
written by a script.
You can use the
for attribute to specify a relationship
between the output element and other elements in the document that
affected the calculation (for example, as inputs or parameters). The
value of the for attribute is a space-separated list of IDs of other
elements.
To learn this concept -
Do Online Practice.
The placeholder attribute
HTML5 introduced a new attribute called
placeholder. This
attribute on <input> and <textarea> elements provides a hint
to the user of what can be entered in the field. The placeholder text
must not contain carriage returns or line-feeds.
Here is the simple syntax for placeholder attribute:
<input type="text" name="search" placeholder="search the web"/>
|
This attribute is supported by latest versions of Mozilla, Safari and Crome browsers only.
To learn this concept -
Do Online Practice.
The autofocus attribute
This is a simple one-step pattern, easily programmed in JavaScript at
the time of document load, automatically focus one particular form
field.
HTML5 introduced a new attribute called
autofocus which would be used as follows:
<input type="text" name="search" autofocus/>
|
This attribute is supported by latest versions of Mozilla, Safari and Crome browsers only.
To learn this concept -
Do Online Practice.
The required attribute
Now you do not need to have javascript for client side validations
like empty text box would never be submitted because HTML5 introduced a
new attribute called
required which would be used as follows and would insist to have a value:
<input type="text" name="search" required/>
|
This attribute is supported by latest versions of Mozilla, Safari and Crome browsers only.
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