How to wait until multiple actions, triggered with one dispatcher, complete?

[ghost]

For example, i have one action Clear and many stores which are listening to it, how to do something only after Clear action is completed in all stores?

[devinivy]

You may be interested in reflux ability to "join" actions: https://github.com/reflux/refluxjs#joining-parallel-listeners-with-composed-listenables

[ghost]

Can you give me some examples? It`s stupid question, but how to use reflux api? I mean how to call its methods.

[devinivy]

It's not stupid at all! In this case you would create a store and create some actions. Stores have the ability to listen to actions. The "join" functionality is a feature of a store that allows it to listen to a composite of several actions. Here's a more complete example,

var Reflux = require('reflux');

var Actions = Reflux.createActions([
  'disarmBomb',
  'saveHostage',
  'recoverData'
]);

var gainHeroBadgeStore = Reflux.createStore({
  init: function() {
    this.joinTrailing(Actions.disarmBomb, Actions.saveHostage, Actions.recoverData, this.onBadge);
  },
  onBadge: function(data) {

    // Let store react to the events above having all taken place

    // Then notify everyone the store has updated
    // this.trigger();
  }
});

Actions.disarmBomb('warehouse');
Actions.recoverData('seedyletter');
Actions.disarmBomb('docks');
Actions.saveHostage('offices', 3);

[ghost]

i think, i have different case, i have many stores listening one action, but not one store listening many actions, thanks for the example, it`s very useful

[devinivy]

If you have many stores listening to one action then it might look more like this,

var Reflux = require('reflux');

var Actions = Reflux.createActions(['disarmBomb']);

var FirstStore = Reflux.createStore({
  init: function() {
    this.listenTo(Actions.disarmBomb, this.onDisarm);
  },
  onDisarm: function(data) {

    // Let store react to the event having taken place

    // Then notify everyone the store has updated
    // this.trigger();
  }
});

var SecondStore = Reflux.createStore({
  init: function() {
    this.listenTo(Actions.disarmBomb, this.onDisarm);
  },
  onDisarm: function(data) {

    // Let store react to the event having taken place

    // Then notify everyone the store has updated
    // this.trigger();
  }
});

Actions.disarmBomb('warehouse');

[devinivy]

Oh, I understand. You should also be able to listen to all stores. So if you have a store that wants to wait for some stores to trigger() after an action it might look like,

this.joinTrailing(Actions.disarmBomb, FirstStore, SecondStore, callback);

[ghost]

Wow, it`s exactly what i meant, thanks, I think that those examples need to be included to documentation

Updated:

callback will be called for each action emmission, but i need it to be called only for the last emmission

i.e

var Actions = Reflux.createActions([
  'action'
]);

var Store1 = Reflux.createStore({
  listenables: [Actions],

  action: function () {
  //do something
  }
});

var Store2 = Reflux.createStore({
  listenables: [Actions],

  action: function () {
  //do something
  }
});

var Store3 = Reflux.createStore({
  init: function () {
    this.joinConcat(Actions.action, Store1, Store2, this.action);
  },

  action: function () {
    console.log('tadah');
  }
});

will cause 2 console logs

[ghost]

Is there anybody? Im still looking for answer)) I have found workaround by using callbacks in actions, it works, but its bad and unreadable

[devinivy]

I don't quite understand. Can you expand your example to include the action call and store updates? Is the join working as described here?

[ghost]

The example is below, i need method action from Store3 to be invoked only when all dispatched actions completed, instead of being called for each action when it`s completed. And yes, join works fine but not for my case.

[devinivy]

What are the actions included in "all dispatched actions"?

[ghost]

An action from each store Store1 and Store2

[semikolon]

joinTrailing should do the job, as explained above

[BryanGrezeszak]

If I understand the issue correctly, would a simple postEmit function (as in a counterpart to the preEmit that already exists) solve this?

So something like:

var Actions = Reflux.createActions(['doAction']);

Actions.doAction.postEmit = function()
{
    console.log('the action is done emitting');
}

Obviously it's kinda impossible to figure out whether whatever you're doing inside your stores on that action is complete (because for all we know you could be starting a 24 hour setTimeout inside there or something, and that's not Reflux's business to know or care) but it would be able to tell you when the action had finished emitting to all of your stores (i.e. all the onDoAction or whatever functions within them will have been called).

[ghost]

Sorry for not responding so long, i ended up using redux instead of reflux, at least it support promises all i needed is something similar to Promise.all([Action1(), Action2(), Action3(), ...])

[BryanGrezeszak]

My bad. I thought you said that you had a situation where you had 1 action and many stores listening and needed to know when that action was emitted to all stores.

Either way, returning promises on an action call sounds good. I'm gonna look into adding that.

[BryanGrezeszak]

Reopened. The fact that the original asker moved on does not resolve the issue.