Is there a way I can track a class change of a website source code on real time?

Question

I'm developing a chrome extension, that must trigger a process if a specific class on a website source has changed. Is there a way of doing that on real time?

Answer 1

Use the MutationObserver interface as shown in Gabriele Romanato's blog

Chrome 18+, Firefox 14+, IE 11+, Safari 6+

// The node to be monitored
var target = $( "#content" )[0];

// Create an observer instance
var observer = new MutationObserver(function( mutations ) {
  mutations.forEach(function( mutation ) {
    var newNodes = mutation.addedNodes; // DOM NodeList
    if( newNodes !== null ) { // If there are new nodes added
        var $nodes = $( newNodes ); // jQuery set
        $nodes.each(function() {
            var $node = $( this );
            if( $node.hasClass( "message" ) ) {
                // do something
            }
        });
    }
  });    
});

// Configuration of the observer:
var config = { 
    attributes: true, 
    childList: true, 
    characterData: true 
};

// Pass in the target node, as well as the observer options
observer.observe(target, config);

// Later, you can stop observing
observer.disconnect();