Often, you'll want a template to display data from a model. Loading the appropriate model is one job of a route.
For example, take this router:
Router.map(function() {
this.route('favorite-posts');
});
To load a model for the favorite-posts
route, you would use the model()
hook in the favorite-posts
route handler:
import Ember from 'ember';
export default Ember.Route.extend({
model() {
return this.get('store').query('post', { favorite: true });
}
});
Typically, the model
hook should return an Ember Data record,
but it can also return any promise object (Ember Data records are promises/),
or a plain JavaScript object or array.
Ember will wait until the data finishes loading (until the promise is resolved/) before rendering the template.
The route will then set the return value from the model
hook as the model
property of the controller.
You will then be able to access the controller's model
property in your template:
Dynamic Models
Some routes always display the same model. For example, the /photos
route will always display the same list of photos available in the
application. If your user leaves this route and comes back later, the
model does not change.
However, you will often have a route whose model will change depending
on user interaction. For example, imagine a photo viewer app. The
/photos
route will render the photos
template with the list of
photos as the model, which never changes. But when the user clicks on a
particular photo, we want to display that model with the photo
template. If the user goes back and clicks on a different photo, we want
to display the photo
template again, this time with a different model.
In cases like this, it's important that we include some information in the URL about not only which template to display, but also which model.
In Ember, this is accomplished by defining routes with dynamic segments.
Once you have defined a route with a dynamic segment,
Ember will extract the value of the dynamic segment from the URL for
you and pass them as a hash to the model
hook as the first argument:
Router.map(function() {
this.route('photo', { path: '/photos/:photo_id' });
});
import Ember from 'ember';
export default Ember.Route.extend({
model(params) {
return this.get('store').findRecord('photo', params.photo_id);
}
});
In the model
hook for routes with dynamic segments, it's your job to
turn the ID (something like 47
or post-slug
) into a model that can
be rendered by the route's template. In the above example, we use the
photo's ID (params.photo_id
) as an argument to Ember Data's findRecord
method.
Note: A route with a dynamic segment will always have its model
hook called when it is entered via the URL.
If the route is entered through a transition (e.g. when using the link-to Handlebars helper/),
and a model context is provided (second argument to link-to
), then the hook is not executed.
If an identifier (such as an id or slug/) is provided instead then the model hook will be executed.
For example, transitioning to the photo
route this way won't cause the model
hook to be executed (because link-to
was passed a model/):
while transitioning this way will cause the model
hook to be executed (because link-to
was passed photo.id
, an
identifier, instead):
Routes without dynamic segments will always execute the model hook.
Multiple Models
Multiple models can be returned through an
RSVP.hash.
The RSVP.hash
takes
parameters that return promises, and when all parameter promises resolve, then
the RSVP.hash
promise resolves. For example:
import Ember from 'ember';
import RSVP from 'rsvp';
export default Ember.Route.extend({
model() {
return RSVP.hash({
songs: this.get('store').findAll('song'),
albums: this.get('store').findAll('album')
});
}
});
In the songs
template, we can specify both models and use the {{#each}}
helper to display
each record in the song model and album model: