CODEWITHSUNDEEP
javascriptbackbone.jsunderscore.js
Ji Mun
Ji Mun

Reputation: 1830

Backbone: (Callback) function even not binding to Collection

I want updatePlays function to be called as a callback function when an AJAX call is successful. I thought that using underscore bind would let me refer 'this' as the Collection object that I actually want to update, but I'm having trouble here. When I get to the function that should update collection, it thinks that 'this' refers to 'window'.

In this situation, a Backbone Model has Backbone Collection, which are made from another backbone models.

in view: 

SomeView: Backbone.View.extend({
  someFunction: function(e) {
    var field = this
    this.picker = new PlayPicker({
      field:field,
      model: new PlaySet({
        plays: new Collections.Plays({}),
        slot: field.model
      })
    })
  }
}) 

PlayPicker:Backbone.View.extend({
 ...
  refresh: function () {
    this.model.update()
  },
....

Collection that's part of model PlaySet

Plays:Backbone.Collection.extend({
  model: Play ,
  initialize: function () {
    plays = this
    _.bind(this.updatePlays, plays) // Where I thought I should bind
  },
  updatePlays: function (plays) {
    new_plays = []

    var i; 
    for (i = 0; i < plays.length; i++){
      new_plays.push(new Play({
        id: plays[i]["id"],
        text: plays[i]["text"]
      }));
    }

    this.reset(new_plays) // Uncaught TypeError: Object [object Window] has no method 'reset' 
  }
})

Model PlaySet

PlaySet: Backbone.Model.extend({
  update: function() {
    this.get('slot').fetchAssociatedPlays(this.get('plays').updatePlays)
  },
})

Model Slot - does the AJAX call

Slot:Backbone.Model.extend({

  ...

  fetchAssociatedPlays: function(update) {
    thisModel = this
    $.ajax({
      url: thisModel.associatedPlaysURL(),
      success: function (collection) {
        update(collection)
      }
    })
  }})

Should this be achievable with underscore bind, and where/how would be the correct way?

Thank you in advance.

Upvotes: 0

Views: 509

Answers (1)

Ji Mun
Ji Mun

Reputation: 1830

The answer to this question has helped me fix my issue: Binding a callback in Backbone.js and Underscore.js

callBack = _.bind(callBack, this);

It was that I need to use a function that is the result of binding the first function with some object.

Upvotes: 0

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