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@addyosmani
Forked from cowboy/HEY-YOU.md
Created October 27, 2011 10:10
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jQuery Tiny Pub/Sub: A really, really, REALLY tiny pub/sub implementation for jQuery 1.7
/*!
* jQuery Tiny Pub/Sub for jQuery 1.7 - v0.1 - 27/10/2011
* Based on @cowboy Ben Alman's REALLY tiny pub/sub.
* 1.7 specific updates by @addyosmani.
* Copyright maintained by @cowboy.
* Dual licensed under the MIT and GPL licenses.
*/
(function($){
// Create a "dummy" jQuery object on which to call on, off and trigger event
// handlers. Although using {} throws errors here in older versions of jQuery
// if you are using 1.7, you won't have this issue.
var o = $({});
// Subscribe to a topic. Works just like on, except the passed handler
// is wrapped in a function so that the event object can be stripped out.
// Even though the event object might be useful, it is unnecessary and
// will only complicate things in the future should the user decide to move
// to a non-$.event-based pub/sub implementation.
$.subscribe = function( topic, fn ) {
// Call fn, stripping out the 1st argument (the event object).
function wrapper() {
return fn.apply( this, Array.prototype.slice.call( arguments, 1 ) );
}
// Add .guid property to function to allow it to be easily unbound. Note
// that $.guid is new in jQuery 1.4+, and $.event.guid was used before.
wrapper.guid = fn.guid = fn.guid || ( $.guid ? $.guid++ : $.event.guid++ );
// Bind the handler.
o.on( topic, wrapper );
};
// Unsubscribe from a topic.
$.unsubscribe = function() {
o.off.apply( o, arguments );
};
// Publish a topic
$.publish = function() {
o.trigger.apply( o, arguments );
};
})(jQuery);
@addyosmani
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Note 2: This is really just a proof of concept. I would almost always recommend using the original (unless we can show there are significant perf benefits to using .on/.off directly over the (now) abstracted .bind()/.unbind() versions etc).

@elijahmanor
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@addy: My guess is that the on/off implementation above should be faster when compared to the previous implementation (bind/unbind) using 1.7. It should only be slightly faster because bind/unbind are just one line wrappers around the on/off methods http://o61.go.ly

With that in mind the on/off methods in 1.7 could very well be slower than the bind/unbind methods in 1.6.4. That would be an interesting comparison. I hope the answer is better performance in 1.7 & not worse ;)

@albanx
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albanx commented Mar 15, 2014

Hi Andy
Excellent pattern. BUt I am having some problems on the context of the callback function. Example:
$.subscribe("dashboard.updateData", this.updateData ); //this--> currenct object

then :
updateData: function(){
this--> here is the event object, but here I will need the original object
}

Is there a way to make callbacks fire in scope of originating object instead ?

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