Empty request payload when saving new record - Ember-data - ember.js

Question

What I'm Trying:
Persist a new record but for some reason the request payload is empty even though the record has data.
Here's a fiddle: http://jsfiddle.net/brancusi/m8VrB/16/
(Disregard the firebase, it's just there so we can inspect the request payload on save.)
Explanation:
You will notice that when you save the record, the request payload is empty.
Ideally the request payload would look something like this:
{
"inventory": {
"entry_time": "2014-02-05",
"client_id": 1,
"user_id": 1,
"product_stock_levels": [
{
"product_id": 1,
"quantity": 2
},
{
"product_id": 2,
"quantity": 0
},
{
"product_id": 3,
"quantity": 8
}
]
}
}
Notes:
This only seems to be a problem when it's a new record. Updating existing records send the correct payload.

Answer 1

You are expecting ember data to embed relationships in a model on save as default. This is not the default behavior.
You could define relationships as being embedded per model. But there is no support for embedded record feature anymore as stated here: https://github.com/emberjs/data/blob/master/TRANSITION.md I am not sure if basic embedded record features still work with latest version of ember data. But you define a record as embedded like this:
App.InventorySerializer = DS.ActiveModelSerializer.extend(DS.EmbeddedRecordsMixin, {
attrs: {
productStockLevels: {embedded: 'always'}
}
});
Because core team stopped support for this embedded records feature and it is very basic I would recommend you to use EmbbededAdapter or EmbeddedMixin if you need support for embedded records. You find them here: https://github.com/pixelhandler/ember-data-extensions
But as Ember Data EmbeddedAdapter is not stable yet. Perhaps you should consider not to embedded records to reduce complexity if you are flexible in defining the api.