Replace hasMany relationships fails

[IsaiahJTurner]

Doing something like:
ama.set("questions", [Question, Question, Question]);
does not work.

[pangratz]

Can you give a little bit more information? What version are you using? What does the model definition for ama look like? Best would be a reproduced example in a JSBin. Here is a starting point: http://emberjs.jsbin.com/lavacavige/edit?html,js,output

[bmac]

Relationships are more complex object then an array so its not possible to set the relationship property directly. Instead can use the setObjects method on the relationship.
ama.get("questions").setObjects([Question, Question, Question]);

[bmac]

My bad @IsaiahJTurner.

@pangratz reminded me that there is special code to handle the case of setting an array:

data/packages/ember-data/lib/system/relationships/has-many.js

Lines 146 to 152 in fcf5452

	set: function(key, records) {
	var relationship = this._internalModel._relationships.get(key);
	relationship.clear();
	Ember.assert("You must pass an array of records to set a hasMany relationship", isArrayLike(records));
	relationship.addRecords(Ember.A(records).mapBy('_internalModel'));
	return relationship.getRecords();
	}

What is the error that you are seeing?

[IsaiahJTurner]

I made a JSBin: http://emberjs.jsbin.com/xemunezoki/edit?html,js,console,output

[pangratz]

OK, so the problem is that store.find returns a PromiseObject. This can't be added directly to a hasMany relationship. The find resolves with the specific record, which in turn can be added to the relationship.

One way to do this is via RSVP.all, which takes an array as argument and resolves when all items in the array are resolved. So the code within your action would become something like:

update: function() {
  var newBooks = [
    this.store.find("book", 4)
  ];

  var model = this.get('model');
  Ember.RSVP.all(newBooks).then(function(newBooks) {
    model.get('books').setObjects(newBooks);

    // or you can use model.set('books', newBooks);
  });
}

---

The thrown error message Uncaught TypeError: Cannot read property 'type' of undefined when setting a PromiseObject is not very helpful. We could add an assertion below this line and check if the contents of the array are actual instances of DS.Model.

@IsaiahJTurner do you want to submit a PR?

[pangratz]

I guess this issue can be closed since an assertion for only passing instances of DS.Model has been added in #3865.