ngrx_user.reducer.ts

import * as fromUsers from '../actions/users.action';  
import { Users } from 'resources/users/users';  
  
export interface UsersState {  
  entities: Users.Entities;  
  loaded: boolean,  
  loading: boolean  
}  
  
export const initialState: UsersState = {  
  entities: {},  
  loaded: false,  
  loading: false  
};  
  
export function reducer(  
  state = initialState,  
  action: fromUsers.UsersAction  
): UsersState {  
  switch (action.type) {  
    case fromUsers.LOAD_USERS: {  
      return {  
        ...state,  
        loading: true  
      };  
    }  
  
    case fromUsers.LOAD_USERS_SUCCESS: {  
      const users = action.payload;  
      const entities = users.reduce((entities: Users.Entities, user) => {  
          return {  
            ...entities,  
            [user.id]: user  
          };  
        },  
        {}  
      );
      
      return {  
        ...state,  
        loading: false,  
        loaded: true,  
        entities  
      };  
    }  
  
    case fromUsers.LOAD_USERS_FAIL: {  
      return {  
        ...state,  
        loading: false,  
        loaded: false  
      };  
    }  
  }  
  
  return state;  
}  
  
export const getUsersEntities = (state: UsersState) => state.entities;  
export const getUsersLoaded = (state: UsersState) => state.loaded;