Wednesday, December 18, 2013

Learn HTML5 - Web Forms 2.0

Learn HTML5 - Web Forms 2.0


Learn HTML5 – Web Forms 2.0


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:


 




























TypeDescription
textA free-form text field, nominally free of line breaks.
passwordA free-form text field for sensitive information, nominally free of line breaks.
checkboxA set of zero or more values from a predefined list.
radioAn enumerated value.
submitA free form of button initiates form submission.
fileAn arbitrary file with a MIME type and optionally a file name.
imageA coordinate, relative to a particular image’s size, with the extra semantic that it must be the last value selected and initiates form submission.
hiddenAn arbitrary string that is not normally displayed to the user.
selectAn enumerated value, much like the radio type.
textareaA free-form text field, nominally with no line break restrictions.
buttonA free form of button which can initiates any event related to button.
TypeDescription

The <input> element in HTML5


Apart from the above mentioned attributes, HTML5 input elements introduced several new values for the type attribute. These are listed below.


 


























TypeDescription
datetimeA 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-localA date and time (year, month, day, hour, minute, second, fractions of a second) encoded according to ISO 8601, with no time zone information.
dateA date (year, month, day) encoded according to ISO 8601.
monthA date consisting of a year and a month encoded according to ISO 8601.
weekA date consisting of a year and a week number encoded according to ISO 8601.
timeA time (hour, minute, seconds, fractional seconds) encoded according to ISO 8601.
numberThis accepts only numerical value. The step attribute specifies the precision, defaulting to 1.
rangeThe range type is used for input fields that should contain a value from a range of numbers.
emailThis 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.
urlThis 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.
TypeDescription

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.


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/>

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"/>

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/>


Learn HTML5 - Web Forms 2.0

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