Question

当我们使用不同的reducer时，重设整个状态的最佳方法是什么？我在使用选择器时遇到了问题，因为在进行重置时它不会带给我初始状态

MetaReducer

import { ActionReducer } from '@ngrx/store';
import { UserActionTypes } from '../../actions/actionTypes';

export function clearStateReducer(reducer: ActionReducer<any>): ActionReducer<any> {
  return (state, action) => {
    if (action.type === UserActionTypes.Logout) {
      state = undefined;
    }
    return reducer(state, action);
  };
}

状态模块

import { NgModule } from '@angular/core';
import { StateService } from './state.service';
import { StoreDevtoolsModule } from '@ngrx/store-devtools';
import { StoreModule } from '@ngrx/store';
import { appReducer } from './reducers';
import { getInitialState } from './state';
import { metaReducers } from './reducers/metaReducers';

@NgModule({
  imports: [
    StoreModule.forRoot(appReducer, {
      initialState: getInitialState(),
      metaReducers,
      runtimeChecks: {
        strictStateImmutability: false,
        strictActionImmutability: false,
        strictStateSerializability: false,
        strictActionSerializability: false
      }
    }),
    StoreDevtoolsModule.instrument({
      maxAge: 25
    })
  ],
  providers: [StateService]
})
export class StateServiceModule {}

Answer 1

您可以通过将状态设置回初始状态来重置

export const postReducer = createReducer(
  initialState,
  on(PostActions.ResetState, (state) => {
    return { state: initialState };
  }),
);

Answer 2

您可能没有分配状态，而是用undefined调用了reducer：

export function clearStateReducer(reducer: ActionReducer<any>): ActionReducer<any> {
  return (state, action) => {
    if (action.type === UserActionTypes.Logout) {
      return reducer(undefined, action);
    }
    return reducer(state, action);
  };
}

NGRX-重置整个状态的最佳方法是什么？

2 个答案: