NGXS Data handlers

This package defines finite number of data status and helps automatically define which of statuses are states in

export enum DataStatus {
  Loaded = "Loaded",
  Loading = "Loading",
  Error = "Error",
  Empty = "Empty",
  Denied = "Denied",
  Modified = "Modified",
}

Also has interface gathering some informations about what happened with data like last time is was succesfully saved on server and last error

export interface DataUnit<T> {
  data: T | null;
  status: DataStatus;
  timestamp?: string;
  error?: Error;
}

Example simple state loading

export interface IDetails {
  a: string;
  b: string;
}

@State<DataUnit<IDetails>>({
  name: 'single',
  defaults: {
    status: DataStatus.Empty,
    data: null,
  },
})
@Injectable()
export class DetailsState {
  @Selector()
  static getData(state: DataUnit<IDetails): IDetails {
    return state.data;
  }

  @Selector()
  static getStatus(state: DataUnit<IDetails): DataStatus {
    return state.status;
  }

  constructor(private service: DetailsService) {}

  @Action(Load)
  load(ctx: StateContext<DataUnit<IDetails>>) {
    startLoad(ctx);
    return this.service.load().pipe(operate(ctx, load));
  }
}

Example complex state

export interface User {
    name: string;
    age: number;
}

export interface IComplexState {
  a: string;
  complexObject: {
    myFancyData: DataUnit<User[]>;
  };
  simpleData: DataUnit<User>;
}

@State<IComplexState>({
  name: 'complex',
  defaults: {
    a: string;
    complexObject: {
      myFancyData: {
        status: DataStatus.Empty,
        data: [],
      },
    };
    simpleData: {
      status: DataStatus.Empty,
      data: null,
    },
  }
})
@Injectable()
export class DetailsState {
  @Selector()
  static getUsersList(state: IComplexState): DataUnit<User[]> {
    return state.complexObject.myFancyData;
  }

  @Selector()
  static getUser(state: IComplexState): DataUnit<User> {
    return state.simpleData;
  }

  constructor(private service: UserService) {}

  @Action(LoadSimpleData)
  loadSimpleData(ctx: StateContext<IComplexState>) {
    startLoad(ctx, 'simpleData');
    return this.service.loadUser().pipe(operate(ctx, load, 'simpleData'));
  }

  @Action(LoadComplexData)
  loadComplexData(ctx: StateContext<IComplexState>) {
    startLoad(ctx, 'complexObject.myFancyData');
    return this.service.loadUsersList().pipe(operate(ctx, load, 'complexObject.myFancyData'));
  }

  @Action(UpdateUser)
  updateUser(ctx: StateContext<IComplexState>) {
    startLoad(ctx, 'complexObject.myFancyData');
    return this.service.updateUserName(ctx.getState().a).pipe(operate(ctx, save, 'simpleData'));
  }
}