和StoreFeatureModule相关的一个错误消息:
main.ts:12 NullInjectorError: R3InjectorError(AppModule)[StoreFeatureModule -> ReducerManager -> ReducerManager -> ReducerManager]: NullInjectorError: No provider for ReducerManager! at NullInjector.get (http://localhost:4200/vendor.js:62758:27) at R3Injector.get (http://localhost:4200/vendor.js:76765:33) at R3Injector.get (http://localhost:4200/vendor.js:76765:33) at R3Injector.get (http://localhost:4200/vendor.js:76765:33) at injectInjectorOnly (http://localhost:4200/vendor.js:62613:33) at Module.ɵɵinject (http://localhost:4200/vendor.js:62623:57) at Object.StoreFeatureModule_Factory [as factory] (http://localhost:4200/vendor.js:139469:380) at R3Injector.hydrate (http://localhost:4200/vendor.js:77003:63) at R3Injector.get (http://localhost:4200/vendor.js:76753:33) at http://localhost:4200/vendor.js:76799:25
实例化StoreFeatureModule token:
使用factory构建token value:
取reducerManager:
报错:
恢复这行被注释掉的代码之后:
看看StoreModule.forRoot的实现源代码:
class StoreModule {
/**
* @param {?} reducers
* @param {?=} config
* @return {?}
*/
static forRoot(reducers, config = {}) {
return {
ngModule: StoreRootModule,
providers: [
{
provide: _ROOT_STORE_GUARD,
useFactory: _provideForRootGuard,
deps: [[Store, new Optional(), new SkipSelf()]],
},
{ provide: _INITIAL_STATE, useValue: config.initialState },
{
provide: INITIAL_STATE,
useFactory: _initialStateFactory,
deps: [_INITIAL_STATE],
},
{ provide: _INITIAL_REDUCERS, useValue: reducers },
{
provide: _STORE_REDUCERS,
useExisting: reducers instanceof InjectionToken ? reducers : _INITIAL_REDUCERS,
},
{
provide: INITIAL_REDUCERS,
deps: [Injector, _INITIAL_REDUCERS, [new Inject(_STORE_REDUCERS)]],
useFactory: _createStoreReducers,
},
{
provide: USER_PROVIDED_META_REDUCERS,
useValue: config.metaReducers ? config.metaReducers : [],
},
{
provide: _RESOLVED_META_REDUCERS,
deps: [META_REDUCERS, USER_PROVIDED_META_REDUCERS],
useFactory: _concatMetaReducers,
},
{
provide: _REDUCER_FACTORY,
useValue: config.reducerFactory
? config.reducerFactory
: combineReducers,
},
{
provide: REDUCER_FACTORY,
deps: [_REDUCER_FACTORY, _RESOLVED_META_REDUCERS],
useFactory: createReducerFactory,
},
ACTIONS_SUBJECT_PROVIDERS,
REDUCER_MANAGER_PROVIDERS,
SCANNED_ACTIONS_SUBJECT_PROVIDERS,
STATE_PROVIDERS,
STORE_PROVIDERS,
provideRuntimeChecks(config.runtimeChecks),
],
};
}
这里就提供了之前报错信息里缺失的reducer: