EmberJS: Creating record which has belongsTo

Question

Let me use Posts and Comments to describe my problem. Inside my post_controller I wish to create a new record for a comment for that current post. What is the ember way to do this?

The relation is set like this:

App.Post = DS.Model.extend({
  comments: hasMany('comment'),
});

App.Comment = DS.Model.extend({
  post: belongsTo('post')
});

Inside my post_controller I want to create a record. I have this inside an action that is triggered from a template:

App.PostController = Ember.ObjectController.extend({
  ...
  actions: {
    createComment: function() {
      var post = this.get('model'); // Edit: Forgot that I had this declared outside createRecord
      var comment = this.store.createRecord('comment', {
        content : "content",
        post : post // This is where the problem is
      });
    }
  }
});

However, I get an error saying: Uncaught TypeError: Cannot read property 'post' of undefined

How do I declare this relationship? Thanks.

Edit: The ember-data error comes from this internal function in ember-data.js:

return Ember.computed(function(key, value) {
    var data = get(this, 'data'),
        store = get(this, 'store'), belongsTo, typeClass;

    if (typeof type === 'string') {
      typeClass = store.modelFor(type);
    } else {
      typeClass = type;
    }

    if (arguments.length === 2) {
      Ember.assert("You can only add a '" + type + "' record to this relationship", !value || value instanceof typeClass);
      return value === undefined ? null : value;
    }

    belongsTo = data[key]; // ERROR OCCURS HERE! 

    if (isNone(belongsTo)) { return null; }

    store.fetchRecord(belongsTo);

    return belongsTo;
  }).property('data').meta(meta);
};

EDIT: Problem solved!

The problem was that I hade given comment an attribute called data. That attribute was in conflict with internal ember. Removing it made my code above work fine.

Toran Billups Toran Billups · Accepted Answer · 2014-01-13T16:01:55

If you declare your post outside of the createRecord (ie- above the var comment = line)

var postModel = this.get('model');

You might be having an issue w/ the "this" keyword inside the createRecord scope

Update

also, do you get the same result for this.get('model') and this.get('content') (from outside that scope) ?

EmberJS: Creating record which has belongsTo

1 Answers