Class BelongsToReference

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.relationship.id.

Example

// models/blog.js
import Model, { belongsTo } from '@ember-data/model';

export default class BlogModel extends Model {
 @belongsTo('user', { async: true, inverse: null }) user;
}

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();
 }

The link Ember Data will use to fetch or reload this belongs-to relationship. By default it uses only the "related" resource linkage.

Example

// models/blog.js
import Model, { belongsTo } from '@ember-data/model';
export default Model.extend({
   user: belongsTo('user', { async: true, inverse: null })
 });

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();
 }

any links that have been received for this relationship

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
import Model, { belongsTo } from '@ember-data/model';

export default class BlogModel extends Model {
  @belongsTo('user', { async: true, inverse: null }) user;
}

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
 });

You may also pass in an options object whose properties will be fed forward. This enables you to pass adapterOptions into the request given to the adapter via the reference.

Example

userRef.load({ adapterOptions: { isPrivate: true } }).then(function(user) {
  userRef.value() === user;
});

import Adapter from '@ember-data/adapter';

export default class UserAdapter extends Adapter {
  findRecord(store, type, id, snapshot) {
    // In the adapter you will have access to adapterOptions.
    let adapterOptions = snapshot.adapterOptions;
  }
});

The meta data for the belongs-to relationship.

Example

// models/blog.js
import Model, { belongsTo } from '@ember-data/model';
export default Model.extend({
   user: belongsTo('user', { async: true, inverse: null })
 });

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 }

push can be used to update the data in the relationship and EmberData will treat the new data as the canonical value of this relationship on the backend. A value of null (e.g. { data: null }) can be passed to clear the relationship.

Example model

import Model, { belongsTo } from '@ember-data/model';

export default class BlogModel extends Model {
   @belongsTo('user', { async: true, inverse: null }) user;
 }

Setup some initial state, note we haven't loaded the user yet:

const blog = store.push({
   data: {
     type: 'blog',
     id: '1',
     relationships: {
       user: {
         data: { type: 'user', id: '1' }
       }
     }
   }
});

const userRef = blog.belongsTo('user');
userRef.id(); // '1'

Update the state using push, note we can do this even without having loaded the user yet by providing a resource-identifier.

Both full a resource and a resource-identifier are supported.

await userRef.push({
   data: {
     type: 'user',
     id: '2',
   }
 });

 userRef.id(); // '2'

You may also pass in links and meta fore the relationship, and sideload additional resources that might be required.

 await userRef.push({
     data: {
       type: 'user',
       id: '2',
     },
     links: {
       related: '/articles/1/author'
     },
     meta: {
       lastUpdated: Date.now()
     },
     included: [
       {
         type: 'user-preview',
         id: '2',
         attributes: {
           username: '@runspired'
         }
       }
     ]
   });

By default, the store will attempt to fetch the record if it is not loaded or its resource data is not included in the call to push before resolving the returned promise with the new state..

Alternatively, pass true as the second argument to avoid fetching unloaded records and instead the promise will resolve with void without attempting to fetch. This is particularly useful if you want to update the state of the relationship without forcing the load of all of the associated record.

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
import Model, { belongsTo } from '@ember-data/model';

export default class BlogModel extends Model {
  @belongsTo('user', { async: true, inverse: null }) user;
}

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
 });

You may also pass in an options object whose properties will be fed forward. This enables you to pass adapterOptions into the request given to the adapter via the reference. A full example can be found in the load method.

Example

userRef.reload({ adapterOptions: { isPrivate: true } })

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

import Model, { hasMany } from '@ember-data/model';

export default class PostModel extends Model {
  @hasMany('comment', { async: true, inverse: null }) comments;
}

let post = store.push({
  data: {
    type: 'post',
    id: 1,
    relationships: {
      comments: {
        data: [{ type: 'comment', id: 1 }]
      }
    }
  }
});

let commentsRef = post.hasMany('comments');

// get the identifier of the reference
if (commentsRef.remoteType() === "ids") {
  let ids = commentsRef.ids();
} else if (commentsRef.remoteType() === "link") {
  let link = commentsRef.link();
}

value() synchronously returns the current value of the belongs-to relationship. Unlike record.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
import Model, { belongsTo } from '@ember-data/model';

export default class BlogModel extends Model {
  @belongsTo('user', { async: true, inverse: null }) user;
}

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
 });