7.6 Models--Finding Records

The store for Ember data provides an interface for retrieving a type of records.

One, retrieving a single record (search Order Records)

1. Use Store.findrecord () to retrieve a record by type and ID. This returns a promise, which is implemented by the requested record:

var  This // = GET/POSTS/1

2. Use Store.peekrecord () to retrieve a record with type and ID, without generating a network request. This will return the record only if it already exists in the sotre.

var  This // = no network request

Second, retrieving Mutiple Records

1. For a given type, use store.findall () to retrieve all the records.

var  This // = get/posts

2. For a given type, using store.peekall () to retrieve all the records, these records have been loaded into the store without generating a network request:

var  This // = no network request

• Store.findall () returns a DS. Promisearray, which is implemented as DS. Recordarray and Store.peekall directly returns a DS. Recordarray.
• Note DS. Recordarray is not a JS array, which is important. It is an object that implements the ember.enumerable . This is important because, for example, if you want to retrieve the records,[] symbol by index, you must use objcetat (index) instead.

Third, querying for multiple records

Ember data provides the ability to query records that meet certain criteria. Calling Store.query () obtains a GET request and serializes the passed object into a query parameter. This method returns the DS as the find method . Promisearray.

For example, we can query all Pserson modelswith the name Peter :

var  This // = = GET To/persons?name=peter

Iv. integrating with the route ' s model Hook

1. As discussed in specifying a Route's model, routes is responsible for telling the template which model to load.

2. the Ember.route model Hook supports out-of-the-box asynchronous values. If you return a promise from the model hook , the router will wait until the promise finishes rendering the template.

3. Using ember data makes it easy to write apps with a single piece of information. Simply return the requested record from the model Hook and let Ember handle the need for a network request.

App/router.js

var Router = Ember.Router.extend ({}); Router.map (function() {  this. Route (' posts ');    this. Route (' Post ', {path: ':p ost_id 'default Router;

App/routes/posts.js

default Ember.Route.extend ({  model () {    returnthis. Store.findall (' Post ') ;  }});

App/routes/post.js

default Ember.Route.extend ({  model (params) {    returnthis. Store.findrecord (' post '), params.post_id);}  )

7.6 Models--Finding Records