class
Concrete injectors implement this interface. Injectors are configured with providers that associate dependencies of various types with injection tokens.
abstract class Injector { static THROW_IF_NOT_FOUND: THROW_IF_NOT_FOUND static NULL: Injector static create(options: StaticProvider[] | { providers: StaticProvider[]; parent?: Injector; name?: string; }, parent?: Injector): Injector abstract get<T>(token: Type<T> | AbstractType<T> | InjectionToken<T>, notFoundValue?: T, flags?: InjectFlags): T }
'any'
Property | Description |
---|---|
static THROW_IF_NOT_FOUND: THROW_IF_NOT_FOUND | |
static NULL: Injector |
create() | ||||||
---|---|---|---|---|---|---|
|
providers | StaticProvider[] | |
parent | Injector | Optional. Default is |
Creates a new injector instance that provides one or more dependencies, according to a given type or types of StaticProvider
.
static create(options: { providers: StaticProvider[]; parent?: Injector; name?: string; }): Injector
options | object | An object with the following properties:
|
Injector
: The new injector instance.
get() | |||||||||
---|---|---|---|---|---|---|---|---|---|
Retrieves an instance from the injector based on the provided token. | |||||||||
|
token | Type | |
notFoundValue | T | Optional. Default is |
flags | InjectFlags | Optional. Default is |
T
: The instance from the injector if defined, otherwise the notFoundValue
.
Error
When the notFoundValue
is undefined
or Injector.THROW_IF_NOT_FOUND
.
abstract get(token: any, notFoundValue?: any): any
Deprecated from v4.0.0 use Type
token | any | |
notFoundValue | any | Optional. Default is |
any
The following example creates a service injector instance.
class Square { name = 'square'; } const injector = Injector.create({providers: [{provide: Square, deps: []}]}); const shape: Square = injector.get(Square); expect(shape.name).toEqual('square'); expect(shape instanceof Square).toBe(true);
const injector: Injector = Injector.create({providers: [{provide: 'validToken', useValue: 'Value'}]}); expect(injector.get('validToken')).toEqual('Value'); expect(() => injector.get('invalidToken')).toThrowError(); expect(injector.get('invalidToken', 'notFound')).toEqual('notFound');
Injector
returns itself when given Injector
as a token:
const injector = Injector.create({providers: []}); expect(injector.get(Injector)).toBe(injector);
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Licensed under the Creative Commons Attribution License 4.0.
https://v11.angular.io/api/core/Injector-0