michael-mckenna

  private channelSubject$ = new BehaviorSubject<Channel[]>([]);
    
  private get channels(): Channel[] {
    return this.channelSubject$.getValue();
  }

  private set channels(val: Channel[]) {
    this.channelSubject$.next(val);
  }

michael-mckenna

  channels$: Observable<Channel[]>;
  selectedChannel$: Observable<Channel>;

  constructor(public channelService: ChannelService) {
    this.channels$ = channelService.channelsChanged$;
    this.selectedChannel$ = channelService.selectedChannel$;
  }

michael-mckenna

const defaultChannels: Channel[] = [
    { name: "Rocket League", id: 1 },
    { name: "Aficionados", id: 2 },
    { name: "Work", id: 3 }
]

export interface ChannelsState {
    channels: Channel[];
    selectedChannelId: ChannelId | null;
}

michael-mckenna

export const selectChannelsState = createFeatureSelector<ChannelsState>('channels');

export const selectChannelList = createSelector(
    selectChannelsState,
    (state: ChannelsState) => state.channels
);

michael-mckenna

  /**
   * Updatess the corresponding channel's name. Triggers change detection by returning a new array.
   * @param channel channel with updated name
   */
  updateChannel(channel: Channel) {
    this.channels = this.channels.map(c => c.id === channel.id ? {...c, name: channel.name} : {...c});
  }

michael-mckenna

  // maintains messages across channels
  private messageDB = {1: [], 2: [], 3: []};

  // Tracks messages for the currently selected channel
  private messageSubject$ = new BehaviorSubject<string[]>([]);
  public readonly messages$ = this.messageSubject$.asObservable();

  private selectedChannelId: number;

  constructor() { 

michael-mckenna

  messages: Observable<string[]>;

  constructor(public messageService: MessageService) { 
    this.messages = messageService.messages$;
  }

michael-mckenna

export const messageAdapter: EntityAdapter<MessageContainer> = createEntityAdapter<MessageContainer>({
    selectId: messageContainer => messageContainer.channelId
});

michael-mckenna

// gets the channel id of the currently selected channel
export const selectCurrentChannelId = createSelector(
    selectMessagesState,
    getSelectedChannelId
);

export const selectMessageEntities = createSelector(
    selectMessagesState,
    selectMessageContainerEntities
);

michael-mckenna

this.messages$ = store.pipe(select(selectCurrentChannelMessages));