Ember Data relationships being overwritten

Question

I've run into this problem on two separate instances now but they are both the same problem. First here are my models for one instance of the problem:

host:

Minicron.Host = DS.Model.extend({
  hostname: DS.attr('string'),
  name: DS.attr('string'),
  created_at: DS.attr('date'),

  jobs: DS.hasMany('job')
});

job:

Minicron.Job = DS.Model.extend({
  name: DS.attr('string'),
  command: DS.attr('string'),
  created_at: DS.attr('date'),

  host: DS.belongsTo('host')
});

The JSON my job model receives:

{
  "jobs":[
    {
      "id":"94e81ce07cec25451ce711fce3d96bea",
      "name":"uname -a",
      "command":"uname -a",
      "created_at":"2014-03-10T16:25:08Z",
      "host":{
        "id":8,
        "hostname":"lucid32",
        "name":"lucid32",
        "created_at":"2014-03-08T18:13:52Z"
      },
      "executions":[
        {
          "id":406,
          "job_id":"94e81ce07cec25451ce711fce3d96bea",
          "host_id":8,
          "created_at":"2014-03-09T18:15:28Z",
          "started_at":"2014-03-09T18:15:28Z",
          "finished_at":"2014-03-09T18:15:28Z",
          "exit_status":0
        }
      ]
    }
  ]
}

and the JSON by host model receives is:

{
  "hosts":[
    {
      "id":8,
      "hostname":"lucid32",
      "name":"lucid32",
      "created_at":"2014-03-08T18:13:52Z",
      "jobs":[
        {
          "id":"94e81ce07cec25451ce711fce3d96bea",
          "name":"uname -a",
          "command":"uname -a",
          "host_id":8,
          "created_at":"2014-03-10T16:25:08Z"
        }
      ]
    }
  ]
}

The problem I'm having is when my host model is loaded the job model's host relationship seems to be overwritten. I presume this is because in the JSON each job a host has has the host_id param and ember is replacing the existing data it knows about that host with basically nothing. My API is a Sinatra app using activerecord and activemodel to serialize my models as JSON so I don't really have an easy way to remove the host_id from the response.

It's also worth noting I'm using the custom serializer here http://mozmonkey.com/2013/12/loading-json-with-embedded-records-into-ember-data-1-0-0-beta/, I couldn't get Ember to recognise my sideloaded data without it.

I've been trying to figure this out for a few days now and I'm all out of ideas :(

Let me know if you have any questions and if it helps the full source for my app is on GitHub https://github.com/jamesrwhite/minicron/tree/master/lib/minicron/hub

Thanks!

jdcravens jdcravens · Accepted Answer · 2014-03-10T17:42:57

You could add the Active Model Serializers gem to your Sinatra app and remove host_id from the response:

class JobSerializer < ActiveModel::Serializer 

  attributes :created_at, :started_at, :finished_at, :exit_status

end

Ember Data relationships being overwritten

1 Answers