/**

* @license

* Copyright Google LLC All Rights Reserved.

*

* Use of this source code is governed by an MIT-style license that can be

* found in the LICENSE file at https://angular.dev/license

*/

import {Injector} from '../di/injector';

import {convertToBitFlags} from '../di/injector_compatibility';

import {InjectFlags, InjectOptions} from '../di/interface/injector';

import {ProviderToken} from '../di/provider_token';

import {NOT_FOUND_CHECK_ONLY_ELEMENT_INJECTOR} from '../view/provider_flags';

/**

* Injector that looks up a value using a specific injector, before falling back to the module

* injector. Used primarily when creating components or embedded views dynamically.

*/

export class ChainedInjector implements Injector {

constructor(

public injector: Injector,

public parentInjector: Injector,

) {}

get<T>(token: ProviderToken<T>, notFoundValue?: T, flags?: InjectFlags | InjectOptions): T {

flags = convertToBitFlags(flags);

const value = this.injector.get<T | typeof NOT_FOUND_CHECK_ONLY_ELEMENT_INJECTOR>(

token,

NOT_FOUND_CHECK_ONLY_ELEMENT_INJECTOR,

flags,

);

if (

value !== NOT_FOUND_CHECK_ONLY_ELEMENT_INJECTOR ||

notFoundValue === (NOT_FOUND_CHECK_ONLY_ELEMENT_INJECTOR as unknown as T)

) {

// Return the value from the root element injector when

// - it provides it

// (value !== NOT_FOUND_CHECK_ONLY_ELEMENT_INJECTOR)

// - the module injector should not be checked

// (notFoundValue === NOT_FOUND_CHECK_ONLY_ELEMENT_INJECTOR)

return value as T;

}

return this.parentInjector.get(token, notFoundValue, flags);

}

}