Class SchemaService public
A SchemaDefinitionService implementation provides the ability to query for various information about a resource in an abstract manner.
How an implementation determines this information is left up to the implementation, this means that schema information could be lazily populated, derived-on-demand, or progressively enhanced during the course of an application's runtime.
The implementation provided to work with @ember-data/model makes use of the
static schema properties on those classes to respond to these queries; however,
that is not a necessary approach. For instance, Schema information could be sideloaded
or pre-flighted for API calls, resulting in no need to bundle and ship potentially
large and expensive JSON or JS schemas to pull information from.
To register a custom schema implementation, extend the store service or lookup and register the schema service first thing on app-boot. Example below shows extending the service.
import Store from '@ember-data/store';
import CustomSchemas from './custom-schemas';
export default class extends Store {
constructor(...args) {
super(...args);
this.registerSchemaDefinitionService(new CustomSchemas());
}
}
At runtime, both the Store and the StoreWrapper provide
access to this service via the getSchemaDefinitionService() method.
```ts export default class extends Component {
Methods
attributesDefinitionFor (}) : AttributesSchema public
Defined in ../ember-data-types/q/schema-service.ts:69
- }
- RecordIdentifier| type: string
identifier
- returns
- AttributesSchema
Returns definitions for all properties of the specified resource that are considered "attributes". Generally these are properties that are not related to book-keeping state on the client and do not represent a linkage to another resource.
The return value should be a dictionary of key:value pairs
where the key is the attribute or property's name and value
is an object with at least the property name which should also
match key.
Optionally, this object may also specify type, which should
be a string reference to a transform, and options which
should be dictionary in which any key:value pairs are permissable.
For instance, when using @ember-data/model, the following attribute
definition:
```ts class extends Model {
doesTypeExist (type) : Boolean public
Defined in ../ember-data-types/q/schema-service.ts:59
- type
- String
- returns
- Boolean
Queries whether the schema-definition-service recognizes type as a resource type
relationshipsDefinitionFor (}) : RelationshipsSchema public
Defined in ../ember-data-types/q/schema-service.ts:112
- }
- RecordIdentifier| type: string
identifier
- returns
- RelationshipsSchema
Returns definitions for all properties of the specified resource that are considered "relationships". Generally these are properties that represent a linkage to another resource.
The return value should be a dictionary of key:value pairs
where the key is the relationship or property's name and value
is an object with at least the following properties:
namewhich should also match thekeyused in the dictionary.kindwhich should be eitherbelongsToorhasManytypewhich should be the related resource's string "type"optionswhich should be a dictionary allowing any key but with at least the below keys present.options.asynca boolean representing whether data for this relationship is typically loaded on-demand.options.inversea string or null representing the field name / key of the corresponding relationship on the inverse resource.
Additionally the following options properties are optional. See Polymorphic Relationships
options.polymorphica boolean representing whether multiple resource types can be used to satisfy this relationship.options.asa string representing the abstract type that the concrete side of a relationship must specify when fulfilling a polymorphic inverse.
For example, the following Model using @ember-data/model would generate this relationships definition by default:
```js class User extends Model {