DS.Adapter
DS.Adapter Class
Extends: Ember.Object
Defined in: addon/adapter.js:7
Module: ember-data
An adapter is an object that receives requests from a store and translates them into the appropriate action to take against your persistence layer. The persistence layer is usually an HTTP API, but may be anything, such as the browser's local storage. Typically the adapter is not invoked directly instead its functionality is accessed through the store
.
Creating an Adapter
Create a new subclass of DS.Adapter
in the app/adapters
folder:
app/adapters/application.js
import DS from 'ember-data'; export default DS.Adapter.extend({ // ...your code here });
Model-specific adapters can be created by putting your adapter class in an app/adapters/
+ model-name
+ .js
file of the application.
app/adapters/post.js
import DS from 'ember-data'; export default DS.Adapter.extend({ // ...Post-specific adapter code goes here });
DS.Adapter
is an abstract base class that you should override in your application to customize it for your backend. The minimum set of methods that you should implement is:
findRecord()
createRecord()
updateRecord()
deleteRecord()
findAll()
query()
To improve the network performance of your application, you can optimize your adapter by overriding these lower-level methods:
findMany()
For an example implementation, see DS.RESTAdapter
, the included REST adapter.
createRecord (store, type, snapshot) Promise
Implement this method in a subclass to handle the creation of new records.
Serializes the record and sends it to the server.
Example
app/adapters/application.js
import Ember from 'ember'; import DS from 'ember-data'; export default DS.Adapter.extend({ createRecord(store, type, snapshot) { let data = this.serialize(snapshot, { includeId: true }); return new Ember.RSVP.Promise(function(resolve, reject) { Ember.$.ajax({ type: 'POST', url: `/${type.modelName}`, dataType: 'json', data: data }).then(function(data) { Ember.run(null, resolve, data); }, function(jqXHR) { jqXHR.then = null; // tame jQuery's ill mannered promises Ember.run(null, reject, jqXHR); }); }); } });
Parameters:
-
store
DS.Store
-
type
DS.Model
- the DS.Model class of the record
-
snapshot
DS.Snapshot
Returns:
-
Promise
- promise
deleteRecord (store, type, snapshot) Promise
Implement this method in a subclass to handle the deletion of a record.
Sends a delete request for the record to the server.
Example
app/adapters/application.js
import Ember from 'ember'; import DS from 'ember-data'; export default DS.Adapter.extend({ deleteRecord(store, type, snapshot) { let data = this.serialize(snapshot, { includeId: true }); let id = snapshot.id; return new Ember.RSVP.Promise(function(resolve, reject) { Ember.$.ajax({ type: 'DELETE', url: `/${type.modelName}/${id}`, dataType: 'json', data: data }).then(function(data) { Ember.run(null, resolve, data); }, function(jqXHR) { jqXHR.then = null; // tame jQuery's ill mannered promises Ember.run(null, reject, jqXHR); }); }); } });
Parameters:
-
store
DS.Store
-
type
DS.Model
- the DS.Model class of the record
-
snapshot
DS.Snapshot
Returns:
-
Promise
- promise
findAll (store, type, sinceToken, snapshotRecordArray) Promise
The findAll()
method is used to retrieve all records for a given type.
Example
app/adapters/application.js
import Ember from 'ember'; import DS from 'ember-data'; export default DS.Adapter.extend({ findAll(store, type, sinceToken) { let query = { since: sinceToken }; return new Ember.RSVP.Promise(function(resolve, reject) { Ember.$.getJSON(`/${type.modelName}`, query).then(function(data) { resolve(data); }, function(jqXHR) { reject(jqXHR); }); }); } });
Parameters:
-
store
DS.Store
-
type
DS.Model
-
sinceToken
String
-
snapshotRecordArray
DS.SnapshotRecordArray
Returns:
-
Promise
- promise
findMany (store, type, ids, snapshots) Promise
The store will call findMany
instead of multiple findRecord
requests to find multiple records at once if coalesceFindRequests is true.
app/adapters/application.js
import Ember from 'ember'; import DS from 'ember-data'; export default DS.Adapter.extend({ findMany(store, type, ids, snapshots) { return new Ember.RSVP.Promise(function(resolve, reject) { Ember.$.ajax({ type: 'GET', url: `/${type.modelName}/`, dataType: 'json', data: { filter: { id: ids.join(',') } } }).then(function(data) { Ember.run(null, resolve, data); }, function(jqXHR) { jqXHR.then = null; // tame jQuery's ill mannered promises Ember.run(null, reject, jqXHR); }); }); } });
Parameters:
Returns:
-
Promise
- promise
findRecord (store, type, id, snapshot) Promise
The findRecord()
method is invoked when the store is asked for a record that has not previously been loaded. In response to findRecord()
being called, you should query your persistence layer for a record with the given ID. The findRecord
method should return a promise that will resolve to a JavaScript object that will be normalized by the serializer.
Here is an example findRecord
implementation:
app/adapters/application.js
import Ember from 'ember'; import DS from 'ember-data'; export default DS.Adapter.extend({ findRecord(store, type, id, snapshot) { return new Ember.RSVP.Promise(function(resolve, reject) { Ember.$.getJSON(`/${type.modelName}/${id}`).then(function(data) { resolve(data); }, function(jqXHR) { reject(jqXHR); }); }); } });
Parameters:
-
store
DS.Store
-
type
DS.Model
-
id
String
-
snapshot
DS.Snapshot
Returns:
-
Promise
- promise
generateIdForRecord (store, type, inputProperties) (String|Number)
If the globally unique IDs for your records should be generated on the client, implement the generateIdForRecord()
method. This method will be invoked each time you create a new record, and the value returned from it will be assigned to the record's primaryKey
.
Most traditional REST-like HTTP APIs will not use this method. Instead, the ID of the record will be set by the server, and your adapter will update the store with the new ID when it calls didCreateRecord()
. Only implement this method if you intend to generate record IDs on the client-side.
The generateIdForRecord()
method will be invoked with the requesting store as the first parameter and the newly created record as the second parameter:
import DS from 'ember-data'; import { v4 } from 'uuid'; export default DS.Adapter.extend({ generateIdForRecord(store, inputProperties) { return v4(); } });
Parameters:
Returns:
-
(String|Number)
- id
groupRecordsForFindMany (store, snapshots) Array
Organize records into groups, each of which is to be passed to separate calls to findMany
.
For example, if your api has nested URLs that depend on the parent, you will want to group records by their parent.
The default implementation returns the records as a single group.
Parameters:
-
store
DS.Store
-
snapshots
Array
Returns:
-
Array
- an array of arrays of records, each of which is to be loaded separately by `findMany`.
query (store, type, query, recordArray) Promise
This method is called when you call query
on the store.
Example
app/adapters/application.js
import Ember from 'ember'; import DS from 'ember-data'; export default DS.Adapter.extend({ query(store, type, query) { return new Ember.RSVP.Promise(function(resolve, reject) { Ember.$.getJSON(`/${type.modelName}`, query).then(function(data) { resolve(data); }, function(jqXHR) { reject(jqXHR); }); }); } });
Parameters:
-
store
DS.Store
-
type
DS.Model
-
query
Object
-
recordArray
DS.AdapterPopulatedRecordArray
Returns:
-
Promise
- promise
queryRecord (store, type, query) Promise
The queryRecord()
method is invoked when the store is asked for a single record through a query object.
In response to queryRecord()
being called, you should always fetch fresh data. Once found, you can asynchronously call the store's push()
method to push the record into the store.
Here is an example queryRecord
implementation:
Example
app/adapters/application.js
import Ember from 'ember'; import DS from 'ember-data'; export default DS.Adapter.extend(DS.BuildURLMixin, { queryRecord(store, type, query) { return new Ember.RSVP.Promise(function(resolve, reject) { Ember.$.getJSON(`/${type.modelName}`, query).then(function(data) { resolve(data); }, function(jqXHR) { reject(jqXHR); }); }); } });
Parameters:
-
store
DS.Store
-
type
subclass of DS.Model
-
query
Object
Returns:
-
Promise
- promise
serialize (snapshot, options) Object
Proxies to the serializer's serialize
method.
Example
app/adapters/application.js
import DS from 'ember-data'; export default DS.Adapter.extend({ createRecord(store, type, snapshot) { let data = this.serialize(snapshot, { includeId: true }); let url = `/${type.modelName}`; // ... } });
Parameters:
-
snapshot
DS.Snapshot
-
options
Object
Returns:
-
Object
- serialized snapshot
shouldBackgroundReloadAll (store, snapshotRecordArray) Boolean
This method is used by the store to determine if the store should reload a record array after the store.findAll
method resolves with a cached record array.
This method is only checked by the store when the store is returning a cached record array.
If this method returns true
the store will re-fetch all records from the adapter.
For example, if you do not want to fetch complex data over a mobile connection, or if the network is down, you can implement shouldBackgroundReloadAll
as follows:
shouldBackgroundReloadAll(store, snapshotArray) { let connection = window.navigator.connection; if (connection === 'cellular' || connection === 'none') { return false; } else { return true; } }
By default this method returns true
, indicating that a background reload should always be triggered.
Parameters:
-
store
DS.Store
-
snapshotRecordArray
DS.SnapshotRecordArray
Returns:
-
Boolean
shouldBackgroundReloadRecord (store, snapshot) Boolean
This method is used by the store to determine if the store should reload a record after the store.findRecord
method resolves a cached record.
This method is only checked by the store when the store is returning a cached record.
If this method returns true
the store will re-fetch a record from the adapter.
For example, if you do not want to fetch complex data over a mobile connection, or if the network is down, you can implement shouldBackgroundReloadRecord
as follows:
shouldBackgroundReloadRecord(store, snapshot) { let connection = window.navigator.connection; if (connection === 'cellular' || connection === 'none') { return false; } else { return true; } }
By default this hook returns true
so the data for the record is updated in the background.
Parameters:
-
store
DS.Store
-
snapshot
DS.Snapshot
Returns:
-
Boolean
shouldReloadAll (store, snapshotRecordArray) Boolean
This method is used by the store to determine if the store should reload all records from the adapter when records are requested by store.findAll
.
If this method returns true
, the store will re-fetch all records from the adapter. If this method returns false
, the store will resolve immediately using the cached records.
For example, if you are building an events ticketing system, in which users can only reserve tickets for 20 minutes at a time, and want to ensure that in each route you have data that is no more than 20 minutes old you could write:
shouldReloadAll(store, snapshotArray) { let snapshots = snapshotArray.snapshots(); return snapshots.any((ticketSnapshot) => { let lastAccessedAt = ticketSnapshot.attr('lastAccessedAt'); let timeDiff = moment().diff(lastAccessedAt, 'minutes'); if (timeDiff > 20) { return true; } else { return false; } }); }
This method would ensure that whenever you do store.findAll('ticket')
you will always get a list of tickets that are no more than 20 minutes old. In case a cached version is more than 20 minutes old, findAll
will not resolve until you fetched the latest versions.
By default this methods returns true
if the passed snapshotRecordArray
is empty (meaning that there are no records locally available yet), otherwise it returns false
.
Note that, with default settings, shouldBackgroundReloadAll
will always re-fetch all the records in the background even if shouldReloadAll
returns false
. You can override shouldBackgroundReloadAll
if this does not suit your use case.
Parameters:
-
store
DS.Store
-
snapshotRecordArray
DS.SnapshotRecordArray
Returns:
-
Boolean
shouldReloadRecord (store, snapshot) Boolean
This method is used by the store to determine if the store should reload a record from the adapter when a record is requested by store.findRecord
.
If this method returns true
, the store will re-fetch a record from the adapter. If this method returns false
, the store will resolve immediately using the cached record.
For example, if you are building an events ticketing system, in which users can only reserve tickets for 20 minutes at a time, and want to ensure that in each route you have data that is no more than 20 minutes old you could write:
shouldReloadRecord(store, ticketSnapshot) { let lastAccessedAt = ticketSnapshot.attr('lastAccessedAt'); let timeDiff = moment().diff(lastAccessedAt, 'minutes'); if (timeDiff > 20) { return true; } else { return false; } }
This method would ensure that whenever you do store.findRecord('ticket',
id)
you will always get a ticket that is no more than 20 minutes old. In case the cached version is more than 20 minutes old, findRecord
will not resolve until you fetched the latest version.
By default this hook returns false
, as most UIs should not block user interactions while waiting on data update.
Note that, with default settings, shouldBackgroundReloadRecord
will always re-fetch the records in the background even if shouldReloadRecord
returns false
. You can override shouldBackgroundReloadRecord
if this does not suit your use case.
Parameters:
-
store
DS.Store
-
snapshot
DS.Snapshot
Returns:
-
Boolean
updateRecord (store, type, snapshot) Promise
Implement this method in a subclass to handle the updating of a record.
Serializes the record update and sends it to the server.
The updateRecord method is expected to return a promise that will resolve with the serialized record. This allows the backend to inform the Ember Data store the current state of this record after the update. If it is not possible to return a serialized record the updateRecord promise can also resolve with undefined
and the Ember Data store will assume all of the updates were successfully applied on the backend.
Example
app/adapters/application.js
import Ember from 'ember'; import DS from 'ember-data'; export default DS.Adapter.extend({ updateRecord(store, type, snapshot) { let data = this.serialize(snapshot, { includeId: true }); let id = snapshot.id; return new Ember.RSVP.Promise(function(resolve, reject) { Ember.$.ajax({ type: 'PUT', url: `/${type.modelName}/${id}`, dataType: 'json', data: data }).then(function(data) { Ember.run(null, resolve, data); }, function(jqXHR) { jqXHR.then = null; // tame jQuery's ill mannered promises Ember.run(null, reject, jqXHR); }); }); } });
Parameters:
-
store
DS.Store
-
type
DS.Model
- the DS.Model class of the record
-
snapshot
DS.Snapshot
Returns:
-
Promise
- promise
coalesceFindRequests{boolean}
By default the store will try to coalesce all fetchRecord
calls within the same runloop into as few requests as possible by calling groupRecordsForFindMany and passing it into a findMany call. You can opt out of this behaviour by either not implementing the findMany hook or by setting coalesceFindRequests to false.
defaultSerializer{String}
If you would like your adapter to use a custom serializer you can set the defaultSerializer
property to be the name of the custom serializer.
Note the defaultSerializer
serializer has a lower priority than a model specific serializer (i.e. PostSerializer
) or the application
serializer.
app/adapters/django.js
import DS from 'ember-data'; export default DS.Adapter.extend({ defaultSerializer: 'django' });
© 2017 Yehuda Katz, Tom Dale and Ember.js contributors
Licensed under the MIT License.
https://emberjs.com/api/data/classes/DS.Adapter.html