title to store this metadata. However with HTML5’s data attribute, storing and parsing this data has become a whole lot easier and cleaner.
The syntax is straightforward. Any attribute prefixed with
data- will be treated as data storage.
<div class="test" data-foo="bar"></div>
jQuery accesses this data like so…
var data = $( 'div.test' ).data( 'foo' ); // returns bar
Support for the data attribute has been added since jQuery version 1.4.3. jQuery’s implementation is smart enough that it can parse the attribute easily and even determine the correct data type used.
What I have found really useful is the fact that the jQuery can parse JSON syntax and return a JSON object. This makes passing data in PHP trivial, using the json_encode method. We also need to use htmlspecialchars method to escape or convert any quotes in the JSON string.
<?php $test = array( 'row' => 1, 'col' => 6, 'color' => 'pink' ); //create array of data you want to pass to jquery $test = json_encode( $test ); //convert array to a JSON string $test = htmlspecialchars( $test, ENT_QUOTES ); //convert any quotes into HTML entities so JSON string behaves as a proper HTML attribute. ?> <div class="test" data-complex="<?php echo $test ; ?>"></div>
The jQuery parses the JSON string like so…
var test = $( 'div.test' ).data( 'complex' ); // returns JSON Object console.log( test.color ); // outputs pink!
Important to note that this method is also backward compatible with older browsers, so there is no excuse not to give it a go!
3 thoughts on “HTML5 Data attributes in HTML and jQuery”
Hi, I’ve tested your code and it doesn’t work for me.
Do you have any idea about how to fix this?
Hi Philippe, you are correct. I forgot to mention that the JSON string needs to be escaped for it to behave properly. I have updated the code now. Thanks for pointing this out.
Its work fine.