CODEWITHSUNDEEP
javascriptbackbone.js
Barnaba
Barnaba

Reputation: 677

How to wait for all event handlers in backbone?

I'm trying to perform some action, when all event handlers for some event are done.

My idea was to pass an object in event:

self.trigger("my_event", {handlers: x, callback: function});

And in the handlers I'd write something like:

handler = function(lock){
  lock.handlers --;
  if (lock.handlers == 0){
    lock.callback();
  }
}

(obviously that'd be the lock object's responsibility, but you can see the idea)

But I don't know how to get information about number of handlers (x in my example) registered for the event. Is this possible? Is there some other way to do this?

Upvotes: 0

Views: 754

Answers (1)

maerics
maerics

Reputation: 156434

I believe that the registered handlers are all called by the "trigger" function itself; so when that call returns, each of the handlers have also. Consider this example:

function checkTriggers() {
  var o = {};
  _.extend(o, Backbone.Events);
  o.on('foo', function(){console.log('ONE');});
  o.on('foo', function(){console.log('TWO');});
  o.trigger('foo');
  console.log('THREE');
}

The log sequence will always be ONE, TWO, THREE. So it seems like you can simply perform your action after the call to "trigger". However, if any callback functions use a delay (e.g. with "setTimeout") then you've got a different problem.

Upvotes: 1

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