Return value of actions

1

how can i return some value from actions?? how action must called to accomplish this issue??

vat r = this.send("someAction", params);

...

    actions:{
      someAction: function(){
          return "someValue";
      }    
    }
1 Like
2

Actions are one way, call the function directly off the target object (controller, router, plain object) if you want a return value.

1 Like
3

How about in the case where you want to test an action,say in QUnit?

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4

Call the action just like you would any other function.

this.get('targetObject.actions.someFunction')();

2 Likes
5

Iā€™ve always wondered this same thing, because what I wanted to return from an action was a promise. Actions on the router have definitely made my application very elegant, but Iā€™ve found not being able to return a promise has always been an annoyance in a few places. Why not allow an action return a promise?

Andrew

6

I believe my previous suggestion is now obsolete, as actions are ā€œprivateā€ now.

As for actions returning promises, Iā€™m not sure what you mean. Actions are oneway, can you post an example of what youā€™re trying to achieve?

7

Could you perhaps create a deferred, hook up to the promise of that deferred, and then resolve / reject it in the actionHandler?

Pseudo code:

triggersAction: function {
Ā  var doneWithAsync = Ember.RSVP.defer(),
Ā Ā Ā Ā Ā  doTaskWithAsyncResult = Ember.K;

Ā  doneWithAsync.promise
Ā Ā Ā  .then(doTaskWithAsyncResult);

Ā  this.sendAction('doAsynchronously', doneWithAsync)
},

actions: {
Ā  doAsynronously: function(deferred) {
Ā Ā Ā  $.getJSON('/my/json').then(function() {
Ā Ā Ā Ā Ā  deferred.resolve('foo');Ā Ā Ā  Ā 
Ā Ā Ā  })
Ā  }
}

Not entirely sure why youā€™d do it this way instead of calling a method directly though ā€¦

8

First, thanks for returning to discuss this and my apologies that all the use cases are not that fresh on my mind. I started working with ember before we had the async router, so some of my concerns may stem from problems I had back then when I did some pretty horrible things to deal with the lack of knowing when a route had finished transitioning. I think transitionTo on a router now returns some sort of object you can trigger on but itā€™s not as important with all the various hooks available in the router.

The case I can think of right now where a return value on a router action would be most useful has to do with how Iā€™m handling modals. In my application, I have a stack of modals and I generate modals by sending a message to create modal of a particular type for a particular object. (The stack is just a CollectionView of modal views). I can close the top modal by sending ā€˜dismissā€™ event through the routing stack. I started using modals because I didnā€™t want to describe all the possible transitions at every route, and at least at the time, I thought the overhead of doing true routing was too heavy. However, I did want the pushstate behavior (i.e. I wanted to be able to use the back button to close the modal). This all works great but the other day I wanted to programmatically open a new modal right after closing another modal. So I would need to somehow trigger on the popstate following the dismiss. If my ā€˜dismissā€™ event returned a promise, I think I could do this pretty elegantly. Iā€™m sure I could pass a handler, but returning promises looks much cleaner.