[wp-trac] [WordPress Trac] #21170: JavaScript actions and filters

[WordPress Trac]

#21170: JavaScript actions and filters
----------------------------+--------------------------
 Reporter:  koopersmith     |       Owner:  koopersmith
     Type:  task (blessed)  |      Status:  new
 Priority:  normal          |   Milestone:  3.5
Component:  General         |     Version:  3.4
 Severity:  normal          |  Resolution:
 Keywords:                  |
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Comment (by CaptainN):

 I added namespace support to SignalsLite.js (all unit tested):

 It works like this:

 '''
 // setup in core somewhere, or elsewhere
 var actions = {
     // simple factory method
     addAction: function( name ) {
         this[ name ] = new SignalLite( this );
     }
 }

 // wp core or someone else, adds the action hooks
 actions.add( 'wpAction' );

 actions.wpAction.ns.add( 'myNamespace' );

 // now the namespaces actions can be used
 actions.wpAction.myNamespace.add( function() {
     // do something with the action
 } );

 // later when it comes time to cleanup:
 actions.wpAction.myNamespace.remove();
 '''

 I didn't add a way to dispatch a Signal only to a namespaced sub-set of
 listeners, because it didn't seem to make sense to expose that kind of
 functionality. If a listener was added to a Signal, it seems inappropriate
 to only send the signal to certain listeners, it adds a second level of
 subscriber sets, and that can be abused to basically duplicate the
 dispatcher functionality, where there should probably be a second named
 action - it may be better to encourage the creation of another distinct
 hook.

 I think event namespaces are mostly useful as a tool for plugin developers
 to use to be able to clean themselves up, without having to retain a
 reference to all the listeners they may add all over.

 jQuery does support namespaced dispatching, and if there was a strong
 desire for namespaced dispatching, it could be added easily to
 SignalsLite.js. I'm not sure how often you'd have plugin or extension
 developers triggering or dispatching actions and filters (like they
 frequently do in jQuery), so it may not really be an issue, unless it's
 wanted for core use.

-- 
Ticket URL: <http://core.trac.wordpress.org/ticket/21170#comment:35>
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