I'm having trouble saving data in this model relationship. My models are as follows:

App.Flow = DS.Model.extend({
  title: DS.attr('string'),
  content: DS.attr('string'),
  isCustom: DS.attr('boolean'),
  params: DS.hasMany('parameter', {async: true})
});

App.Parameter = DS.Model.extend({
  flow: DS.belongsTo('flow'),
  param: DS.attr('string'),
  param_tooltip: DS.attr('string'),
  param_value: DS.attr('string')
});

As you can see, I want Flows to have multiple Parameters. I have a rudimentary setup using Flow and Parameter fixtures, which behave as expected in the templates. However, when I try to create new ones in the controller, I have trouble setting the flow and parameter values correctly.

var p = this.store.createRecord('parameter', {
  param: "foo",
  param_tooltip: "world",
  param_value: "hello"
});

var f = this.store.createRecord('flow', {
  title: 'job',
  content: title,
  isCustom: true,
  params: [p] // doesn't seem to work
});

f.set('params', [p]); // doesn't seem to work
p.set('flow', f); // also doesn't seem to work

// Save the new model
p.save();
f.save();

I've tried a lot of solutions after staring at this and StackOverflow for a while (not just the ones listed). I'm not really sure what to try next. One thing that I noticed in the Ember inspector was that the ids of these created elements were not integers (they were something like the string 'fixture_0'), but I'm not really sure why that would be, whether its related, or how to fix it.

Thanks!