Document how to model a many-to-many relationship

Currently, you must explicitly model the join model.

Eventually, we will add a has_and_belongs_to_many, similar to Rails.

[samselikoff]

@morhook thank you. With the 3.x beta series underway this should much simpler very soon. You can follow along at https://github.com/samselikoff/ember-cli-mirage/pull/965

[scottfisk]

So I understand the “explicitly create a join model” but do not understand how I make this join model correctly translate to a 2 sided hasMany in ember data. Perhaps that is the sort of thing you are talking about documenting? Maybe something in the serializer? Below is the recommended setup I have gathered from the issues. Mirage models:

// mirage/models/post.js
export default Model.extend({
  postTags: hasMany()
});

// mirage/models/tag.js
export default Model.extend({
  postTags: hasMany()
});

// mirage/models/post-tag.js
export default Model.extend({
  post: belongsTo(),
  tag: belongsTo()
});

And some fixtures:

// mirage/fixtures/posts.js
export default [
  {
    id: 1
    title: "Post 1"
  }
];

// mirage/fixtures/tags.js
export default [
  {
    id: 1,
    text: "Tag 1"
  },
  {
    id: 2,
    text: "Tag 2"
  }
];

// mirage/fixtures/post-tags.js
export default [
  {
    postId: 1,
    tagId: 1
  },
  {
    postId: 1,
    tagId: 2
  }
];

With the ember data models being:

//app/models/post.js
export default Model.extend({
  tags: hasMany('tag', { async: true })
});

//app/models/tag.js
export default Model.extend({
  posts: hasMany('post', { async: true })
});

After reading through the issues the one thing I am missing is the best practice using mirage to wire up the tags and posts async hasMany relations so it works with the ember data setup. From the declarations above I wouldn’t expect posts or tags to work in ember data so how do I go about that?