Sometimes, especially when nesting resources, we find ourselves needing to have some kind of connection between two controllers. Let's take this router as an example:
var Router = Ember.Router.extend({});
Router.map(function() {
this.route("post", { path: "/posts/:post_id" }, function() {
this.route("comments", { path: "/comments" });
});
});
export default Router;
If we visit a /posts/1/comments
URL, our Post
model will get
loaded into a PostController
's model, which means it is not directly
accessible in the CommentsController
. We might however want to display
some information about it in the comments
template.
To be able to do this we define our CommentsController
to need
the PostController
which has our desired Post
model.
export default Ember.ArrayController.extend({
needs: "post"
});
This tells Ember that our CommentsController
should be able to access
its parent PostController
, which can be done via controllers.post
(either in the template or in the controller itself). In order to get the
actual Post
model, we need to refer to controllers.post.model
:
export default Ember.ArrayController.extend({
needs: "post",
post: Ember.computed.alias("controllers.post.model")
});
If you want to connect multiple controllers together, you can specify an array of controller names:
export default Ember.Controller.extend({
needs: ['post', 'comments']
});
For more information about dependency injection and needs
in Ember.js,
see the dependency injection guide.
For more information about aliases, see the API docs for
aliased properties.