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ReflectiveInjector

A ReflectiveDependency injection container used for instantiating objects and resolving dependencies.

查看"说明"...

已弃用: from v5 - slow and brings in a lot of code, Use Injector.create instead.

      
      abstract class ReflectiveInjector implements Injector {
  static resolve(providers: Provider[]): ResolvedReflectiveProvider[]
  static resolveAndCreate(providers: Provider[], parent?: Injector): ReflectiveInjector
  static fromResolvedProviders(providers: ResolvedReflectiveProvider[], parent?: Injector): ReflectiveInjector
  abstract parent: Injector | null
  abstract resolveAndCreateChild(providers: Provider[]): ReflectiveInjector
  abstract createChildFromResolved(providers: ResolvedReflectiveProvider[]): ReflectiveInjector
  abstract resolveAndInstantiate(provider: Provider): any
  abstract instantiateResolved(provider: ResolvedReflectiveProvider): any
  abstract get(token: any, notFoundValue?: any): any
}

说明

An Injector is a replacement for a new operator, which can automatically resolve the constructor dependencies.

In typical use, application code asks for the dependencies in the constructor and they are resolved by the Injector.

静态方法

resolve()

Turns an array of provider definitions into an array of resolved providers.

static resolve(providers: Provider[]): ResolvedReflectiveProvider[]
      
      static resolve(providers: Provider[]): ResolvedReflectiveProvider[]
参数
providers Provider[]
返回值

ResolvedReflectiveProvider[]

A resolution is a process of flattening multiple nested arrays and converting individual providers into an array of ResolvedReflectiveProviders.

使用说明

Example
@Injectable() class Engine { } @Injectable() class Car { constructor(public engine:Engine) {} } var providers = ReflectiveInjector.resolve([Car, [[Engine]]]); expect(providers.length).toEqual(2); expect(providers[0] instanceof ResolvedReflectiveProvider).toBe(true); expect(providers[0].key.displayName).toBe("Car"); expect(providers[0].dependencies.length).toEqual(1); expect(providers[0].factory).toBeDefined(); expect(providers[1].key.displayName).toBe("Engine"); });
      
      
  1. @Injectable()
  2. class Engine {
  3. }
  4.  
  5. @Injectable()
  6. class Car {
  7.   constructor(public engine:Engine) {}
  8. }
  9.  
  10. var providers = ReflectiveInjector.resolve([Car, [[Engine]]]);
  11.  
  12. expect(providers.length).toEqual(2);
  13.  
  14. expect(providers[0] instanceof ResolvedReflectiveProvider).toBe(true);
  15. expect(providers[0].key.displayName).toBe("Car");
  16. expect(providers[0].dependencies.length).toEqual(1);
  17. expect(providers[0].factory).toBeDefined();
  18.  
  19. expect(providers[1].key.displayName).toBe("Engine");
  20. });

resolveAndCreate()

Resolves an array of providers and creates an injector from those providers.

static resolveAndCreate(providers: Provider[], parent?: Injector): ReflectiveInjector
      
      static resolveAndCreate(providers: Provider[], parent?: Injector): ReflectiveInjector
参数
providers Provider[]
parent Injector

可选. 默认值是 undefined.

返回值

ReflectiveInjector

The passed-in providers can be an array of Type, Provider, or a recursive array of more providers.

使用说明

Example
@Injectable() class Engine { } @Injectable() class Car { constructor(public engine:Engine) {} } var injector = ReflectiveInjector.resolveAndCreate([Car, Engine]); expect(injector.get(Car) instanceof Car).toBe(true);
      
      @Injectable()
class Engine {
}

@Injectable()
class Car {
  constructor(public engine:Engine) {}
}

var injector = ReflectiveInjector.resolveAndCreate([Car, Engine]);
expect(injector.get(Car) instanceof Car).toBe(true);

fromResolvedProviders()

Creates an injector from previously resolved providers.

static fromResolvedProviders(providers: ResolvedReflectiveProvider[], parent?: Injector): ReflectiveInjector
      
      static fromResolvedProviders(providers: ResolvedReflectiveProvider[], parent?: Injector): ReflectiveInjector
参数
providers ResolvedReflectiveProvider[]
parent Injector

可选. 默认值是 undefined.

返回值

ReflectiveInjector

This API is the recommended way to construct injectors in performance-sensitive parts.

使用说明

Example
@Injectable() class Engine { } @Injectable() class Car { constructor(public engine:Engine) {} } var providers = ReflectiveInjector.resolve([Car, Engine]); var injector = ReflectiveInjector.fromResolvedProviders(providers); expect(injector.get(Car) instanceof Car).toBe(true);
      
      
  1. @Injectable()
  2. class Engine {
  3. }
  4.  
  5. @Injectable()
  6. class Car {
  7.   constructor(public engine:Engine) {}
  8. }
  9.  
  10. var providers = ReflectiveInjector.resolve([Car, Engine]);
  11. var injector = ReflectiveInjector.fromResolvedProviders(providers);
  12. expect(injector.get(Car) instanceof Car).toBe(true);

属性

属性说明
abstract parent: Injector | null 只读

Parent of this injector.

方法

resolveAndCreateChild()

Resolves an array of providers and creates a child injector from those providers.

abstract resolveAndCreateChild(providers: Provider[]): ReflectiveInjector
      
      abstract resolveAndCreateChild(providers: Provider[]): ReflectiveInjector
参数
providers Provider[]
返回值

ReflectiveInjector

The passed-in providers can be an array of Type, Provider, or a recursive array of more providers.

使用说明

Example
class ParentProvider {} class ChildProvider {} var parent = ReflectiveInjector.resolveAndCreate([ParentProvider]); var child = parent.resolveAndCreateChild([ChildProvider]); expect(child.get(ParentProvider) instanceof ParentProvider).toBe(true); expect(child.get(ChildProvider) instanceof ChildProvider).toBe(true); expect(child.get(ParentProvider)).toBe(parent.get(ParentProvider));
      
      class ParentProvider {}
class ChildProvider {}

var parent = ReflectiveInjector.resolveAndCreate([ParentProvider]);
var child = parent.resolveAndCreateChild([ChildProvider]);

expect(child.get(ParentProvider) instanceof ParentProvider).toBe(true);
expect(child.get(ChildProvider) instanceof ChildProvider).toBe(true);
expect(child.get(ParentProvider)).toBe(parent.get(ParentProvider));

createChildFromResolved()

Creates a child injector from previously resolved providers.

abstract createChildFromResolved(providers: ResolvedReflectiveProvider[]): ReflectiveInjector
      
      abstract createChildFromResolved(providers: ResolvedReflectiveProvider[]): ReflectiveInjector
参数
providers ResolvedReflectiveProvider[]
返回值

ReflectiveInjector

This API is the recommended way to construct injectors in performance-sensitive parts.

使用说明

Example
class ParentProvider {} class ChildProvider {} var parentProviders = ReflectiveInjector.resolve([ParentProvider]); var childProviders = ReflectiveInjector.resolve([ChildProvider]); var parent = ReflectiveInjector.fromResolvedProviders(parentProviders); var child = parent.createChildFromResolved(childProviders); expect(child.get(ParentProvider) instanceof ParentProvider).toBe(true); expect(child.get(ChildProvider) instanceof ChildProvider).toBe(true); expect(child.get(ParentProvider)).toBe(parent.get(ParentProvider));
      
      
  1. class ParentProvider {}
  2. class ChildProvider {}
  3.  
  4. var parentProviders = ReflectiveInjector.resolve([ParentProvider]);
  5. var childProviders = ReflectiveInjector.resolve([ChildProvider]);
  6.  
  7. var parent = ReflectiveInjector.fromResolvedProviders(parentProviders);
  8. var child = parent.createChildFromResolved(childProviders);
  9.  
  10. expect(child.get(ParentProvider) instanceof ParentProvider).toBe(true);
  11. expect(child.get(ChildProvider) instanceof ChildProvider).toBe(true);
  12. expect(child.get(ParentProvider)).toBe(parent.get(ParentProvider));

resolveAndInstantiate()

Resolves a provider and instantiates an object in the context of the injector.

abstract resolveAndInstantiate(provider: Provider): any
      
      abstract resolveAndInstantiate(provider: Provider): any
参数
provider Provider
返回值

any

The created object does not get cached by the injector.

使用说明

Example
@Injectable() class Engine { } @Injectable() class Car { constructor(public engine:Engine) {} } var injector = ReflectiveInjector.resolveAndCreate([Engine]); var car = injector.resolveAndInstantiate(Car); expect(car.engine).toBe(injector.get(Engine)); expect(car).not.toBe(injector.resolveAndInstantiate(Car));
      
      
  1. @Injectable()
  2. class Engine {
  3. }
  4.  
  5. @Injectable()
  6. class Car {
  7.   constructor(public engine:Engine) {}
  8. }
  9.  
  10. var injector = ReflectiveInjector.resolveAndCreate([Engine]);
  11.  
  12. var car = injector.resolveAndInstantiate(Car);
  13. expect(car.engine).toBe(injector.get(Engine));
  14. expect(car).not.toBe(injector.resolveAndInstantiate(Car));

instantiateResolved()

Instantiates an object using a resolved provider in the context of the injector.

abstract instantiateResolved(provider: ResolvedReflectiveProvider): any
      
      abstract instantiateResolved(provider: ResolvedReflectiveProvider): any
参数
provider ResolvedReflectiveProvider
返回值

any

The created object does not get cached by the injector.

使用说明

Example
@Injectable() class Engine { } @Injectable() class Car { constructor(public engine:Engine) {} } var injector = ReflectiveInjector.resolveAndCreate([Engine]); var carProvider = ReflectiveInjector.resolve([Car])[0]; var car = injector.instantiateResolved(carProvider); expect(car.engine).toBe(injector.get(Engine)); expect(car).not.toBe(injector.instantiateResolved(carProvider));
      
      
  1. @Injectable()
  2. class Engine {
  3. }
  4.  
  5. @Injectable()
  6. class Car {
  7.   constructor(public engine:Engine) {}
  8. }
  9.  
  10. var injector = ReflectiveInjector.resolveAndCreate([Engine]);
  11. var carProvider = ReflectiveInjector.resolve([Car])[0];
  12. var car = injector.instantiateResolved(carProvider);
  13. expect(car.engine).toBe(injector.get(Engine));
  14. expect(car).not.toBe(injector.instantiateResolved(carProvider));

get()

abstract get(token: any, notFoundValue?: any): any
      
      abstract get(token: any, notFoundValue?: any): any
参数
token any
notFoundValue any

可选. 默认值是 undefined.

返回值

any

使用说明

Example

The following example creates an Injector configured to create Engine and Car.

@Injectable() class Engine { } @Injectable() class Car { constructor(public engine:Engine) {} } var injector = ReflectiveInjector.resolveAndCreate([Car, Engine]); var car = injector.get(Car); expect(car instanceof Car).toBe(true); expect(car.engine instanceof Engine).toBe(true);
      
      
  1. @Injectable()
  2. class Engine {
  3. }
  4.  
  5. @Injectable()
  6. class Car {
  7.   constructor(public engine:Engine) {}
  8. }
  9.  
  10. var injector = ReflectiveInjector.resolveAndCreate([Car, Engine]);
  11. var car = injector.get(Car);
  12. expect(car instanceof Car).toBe(true);
  13. expect(car.engine instanceof Engine).toBe(true);

Notice, we don't use the new operator because we explicitly want to have the Injector resolve all of the object's dependencies automatically.