DS.BelongsToReference
DS.BelongsToReference Class
Extends: DS.Reference
Defined in: addon/-private/system/references/belongs-to.js:9
Module: ember-data
A BelongsToReference is a low level API that allows users and addon author to perform meta-operations on a belongs-to relationship.
idString
The id
of the record that this reference refers to. Together, the type()
and id()
methods form a composite key for the identity map. This can be used to access the id of an async relationship without triggering a fetch that would normally happen if you attempted to use record.get('relationship.id')
.
Example
// models/blog.js export default DS.Model.extend({ user: DS.belongsTo({ async: true }) }); let blog = store.push({ data: { type: 'blog', id: 1, relationships: { user: { data: { type: 'user', id: 1 } } } } }); let userRef = blog.belongsTo('user'); // get the identifier of the reference if (userRef.remoteType() === "id") { let id = userRef.id(); }
Returns:
-
String
- The id of the record in this belongsTo relationship.
linkString
The link Ember Data will use to fetch or reload this belongs-to relationship.
Example
// models/blog.js export default DS.Model.extend({ user: DS.belongsTo({ async: true }) }); let blog = store.push({ data: { type: 'blog', id: 1, relationships: { user: { links: { related: '/articles/1/author' } } } } }); let userRef = blog.belongsTo('user'); // get the identifier of the reference if (userRef.remoteType() === "link") { let link = userRef.link(); }
Returns:
-
String
- The link Ember Data will use to fetch or reload this belongs-to relationship.
loadPromise
Loads a record in a belongs to relationship if it is not already loaded. If the relationship is already loaded this method does not trigger a new load.
Example
// models/blog.js export default DS.Model.extend({ user: DS.belongsTo({ async: true }) }); let blog = store.push({ data: { type: 'blog', id: 1, relationships: { user: { data: { type: 'user', id: 1 } } } } }); let userRef = blog.belongsTo('user'); userRef.value(); // null userRef.load().then(function(user) { userRef.value() === user });
Returns:
-
Promise
- a promise that resolves with the record in this belongs-to relationship.
metaObject
The meta data for the belongs-to relationship.
Example
// models/blog.js export default DS.Model.extend({ user: DS.belongsTo({ async: true }) }); let blog = store.push({ data: { type: 'blog', id: 1, relationships: { user: { links: { related: { href: '/articles/1/author', meta: { lastUpdated: 1458014400000 } } } } } } }); let userRef = blog.belongsTo('user'); userRef.meta() // { lastUpdated: 1458014400000 }
Returns:
-
Object
- The meta information for the belongs-oo relationship.
push (objectOrPromise) Promise
push
can be used to update the data in the relationship and Ember Data will treat the new data as the conanical value of this relationship on the backend.
Example
// models/blog.js export default DS.Model.extend({ user: DS.belongsTo({ async: true }) }); let blog = store.push({ data: { type: 'blog', id: 1, relationships: { user: { data: { type: 'user', id: 1 } } } } }); let userRef = blog.belongsTo('user'); // provide data for reference userRef.push({ data: { type: 'user', id: 1, attributes: { username: "@user" } } }).then(function(user) { userRef.value() === user; });
Parameters:
-
objectOrPromise
Object|Promise
- a promise that resolves to a JSONAPI document object describing the new value of this relationship.
Returns:
-
Promise
- A promise that resolves with the new value in this belongs-to relationship.
reloadPromise
Triggers a reload of the value in this relationship. If the remoteType is "link"
Ember Data will use the relationship link to reload the relationship. Otherwise it will reload the record by its id.
Example
// models/blog.js export default DS.Model.extend({ user: DS.belongsTo({ async: true }) }); let blog = store.push({ data: { type: 'blog', id: 1, relationships: { user: { data: { type: 'user', id: 1 } } } } }); let userRef = blog.belongsTo('user'); userRef.reload().then(function(user) { userRef.value() === user });
Returns:
-
Promise
- a promise that resolves with the record in this belongs-to relationship after the reload has completed.
remoteTypeString
This returns a string that represents how the reference will be looked up when it is loaded. If the relationship has a link it will use the "link" otherwise it defaults to "id".
Example
// models/blog.js export default DS.Model.extend({ user: DS.belongsTo({ async: true }) }); let blog = store.push({ type: 'blog', id: 1, relationships: { user: { data: { type: 'user', id: 1 } } } }); let userRef = blog.belongsTo('user'); // get the identifier of the reference if (userRef.remoteType() === "id") { let id = userRef.id(); } else if (userRef.remoteType() === "link") { let link = userRef.link(); }
Returns:
-
String
- The name of the remote type. This should either be "link" or "id"
value (objectOrPromise) DS.Model
value()
synchronously returns the current value of the belongs-to relationship. Unlike record.get('relationshipName')
, calling value()
on a reference does not trigger a fetch if the async relationship is not yet loaded. If the relationship is not loaded it will always return null
.
Example
// models/blog.js export default DS.Model.extend({ user: DS.belongsTo({ async: true }) }); let blog = store.push({ data: { type: 'blog', id: 1, relationships: { user: { data: { type: 'user', id: 1 } } } } }); let userRef = blog.belongsTo('user'); userRef.value(); // null // provide data for reference userRef.push({ data: { type: 'user', id: 1, attributes: { username: "@user" } } }).then(function(user) { userRef.value(); // user });
Parameters:
-
objectOrPromise
Object|Promise
- a promise that resolves to a JSONAPI document object describing the new value of this relationship.
Returns:
-
DS.Model
- the record in this relationship
© 2017 Yehuda Katz, Tom Dale and Ember.js contributors
Licensed under the MIT License.
https://emberjs.com/api/data/classes/DS.BelongsToReference.html