lemmy-ui/src/shared/components/communities.tsx

import { Component, linkEvent } from 'inferno';
import { Helmet } from 'inferno-helmet';
import { Subscription } from 'rxjs';
import { retryWhen, delay, take } from 'rxjs/operators';
import {
  UserOperation,
  Community,
  ListCommunitiesResponse,
  CommunityResponse,
  FollowCommunityForm,
  ListCommunitiesForm,
  SortType,
  WebSocketJsonResponse,
  GetSiteResponse,
  Site,
} from 'lemmy-js-client';
import { WebSocketService } from '../services';
import {
  wsJsonToRes,
  toast,
  getPageFromProps,
  isBrowser,
  lemmyHttp,
  setAuth,
} from '../utils';
import { CommunityLink } from './community-link';
import { i18n } from '../i18next';
import { IsoData } from 'shared/interfaces';

const communityLimit = 100;

interface CommunitiesState {
  communities: Community[];
  page: number;
  loading: boolean;
  site: Site;
}

interface CommunitiesProps {
  page: number;
}

export class Communities extends Component<any, CommunitiesState> {
  private subscription: Subscription;
  private emptyState: CommunitiesState = {
    communities: [],
    loading: true,
    page: getPageFromProps(this.props),
    site: undefined,
  };

  constructor(props: any, context: any) {
    super(props, context);
    this.state = this.emptyState;
    let isoData: IsoData;

    if (isBrowser()) {
      this.subscription = WebSocketService.Instance.subject
        .pipe(retryWhen(errors => errors.pipe(delay(3000), take(10))))
        .subscribe(
          msg => this.parseMessage(msg),
          err => console.error(err),
          () => console.log('complete')
        );
      isoData = window.isoData;
    } else {
      isoData = this.context.router.staticContext;
    }

    this.state.site = isoData.site.site;

    // Only fetch the data if coming from another route
    if (isoData.path == this.context.router.route.match.path) {
      this.state.communities = isoData.routeData[0].communities;
      this.state.loading = false;
    } else {
      this.refetch();
    }
  }

  componentWillUnmount() {
    if (isBrowser()) {
      this.subscription.unsubscribe();
    }
  }

  static getDerivedStateFromProps(props: any): CommunitiesProps {
    return {
      page: getPageFromProps(props),
    };
  }

  componentDidUpdate(_: any, lastState: CommunitiesState) {
    if (lastState.page !== this.state.page) {
      this.setState({ loading: true });
      this.refetch();
    }
  }

  get documentTitle(): string {
    if (this.state.site) {
      return `${i18n.t('communities')} - ${this.state.site.name}`;
    } else {
      return 'Lemmy';
    }
  }

  render() {
    return (
      <div class="container">
        <Helmet title={this.documentTitle} />
        {this.state.loading ? (
          <h5 class="">
            <svg class="icon icon-spinner spin">
              <use xlinkHref="#icon-spinner"></use>
            </svg>
          </h5>
        ) : (
          <div>
            <h5>{i18n.t('list_of_communities')}</h5>
            <div class="table-responsive">
              <table id="community_table" class="table table-sm table-hover">
                <thead class="pointer">
                  <tr>
                    <th>{i18n.t('name')}</th>
                    <th>{i18n.t('category')}</th>
                    <th class="text-right">{i18n.t('subscribers')}</th>
                    <th class="text-right d-none d-lg-table-cell">
                      {i18n.t('posts')}
                    </th>
                    <th class="text-right d-none d-lg-table-cell">
                      {i18n.t('comments')}
                    </th>
                    <th></th>
                  </tr>
                </thead>
                <tbody>
                  {this.state.communities.map(community => (
                    <tr>
                      <td>
                        <CommunityLink community={community} />
                      </td>
                      <td>{community.category_name}</td>
                      <td class="text-right">
                        {community.number_of_subscribers}
                      </td>
                      <td class="text-right d-none d-lg-table-cell">
                        {community.number_of_posts}
                      </td>
                      <td class="text-right d-none d-lg-table-cell">
                        {community.number_of_comments}
                      </td>
                      <td class="text-right">
                        {community.subscribed ? (
                          <span
                            class="pointer btn-link"
                            onClick={linkEvent(
                              community.id,
                              this.handleUnsubscribe
                            )}
                          >
                            {i18n.t('unsubscribe')}
                          </span>
                        ) : (
                          <span
                            class="pointer btn-link"
                            onClick={linkEvent(
                              community.id,
                              this.handleSubscribe
                            )}
                          >
                            {i18n.t('subscribe')}
                          </span>
                        )}
                      </td>
                    </tr>
                  ))}
                </tbody>
              </table>
            </div>
            {this.paginator()}
          </div>
        )}
      </div>
    );
  }

  paginator() {
    return (
      <div class="mt-2">
        {this.state.page > 1 && (
          <button
            class="btn btn-secondary mr-1"
            onClick={linkEvent(this, this.prevPage)}
          >
            {i18n.t('prev')}
          </button>
        )}

        {this.state.communities.length > 0 && (
          <button
            class="btn btn-secondary"
            onClick={linkEvent(this, this.nextPage)}
          >
            {i18n.t('next')}
          </button>
        )}
      </div>
    );
  }

  updateUrl(paramUpdates: CommunitiesProps) {
    const page = paramUpdates.page || this.state.page;
    this.props.history.push(`/communities/page/${page}`);
  }

  nextPage(i: Communities) {
    i.updateUrl({ page: i.state.page + 1 });
  }

  prevPage(i: Communities) {
    i.updateUrl({ page: i.state.page - 1 });
  }

  handleUnsubscribe(communityId: number) {
    let form: FollowCommunityForm = {
      community_id: communityId,
      follow: false,
    };
    WebSocketService.Instance.followCommunity(form);
  }

  handleSubscribe(communityId: number) {
    let form: FollowCommunityForm = {
      community_id: communityId,
      follow: true,
    };
    WebSocketService.Instance.followCommunity(form);
  }

  refetch() {
    let listCommunitiesForm: ListCommunitiesForm = {
      sort: SortType.TopAll,
      limit: communityLimit,
      page: this.state.page,
    };

    WebSocketService.Instance.listCommunities(listCommunitiesForm);
  }

  static fetchInitialData(auth: string, path: string): Promise<any>[] {
    let pathSplit = path.split('/');
    let page = pathSplit[2] ? Number(pathSplit[2]) : 1;
    let listCommunitiesForm: ListCommunitiesForm = {
      sort: SortType.TopAll,
      limit: communityLimit,
      page,
    };
    setAuth(listCommunitiesForm, auth);

    return [lemmyHttp.listCommunities(listCommunitiesForm)];
  }

  parseMessage(msg: WebSocketJsonResponse) {
    console.log(msg);
    let res = wsJsonToRes(msg);
    if (msg.error) {
      toast(i18n.t(msg.error), 'danger');
      return;
    } else if (res.op == UserOperation.ListCommunities) {
      let data = res.data as ListCommunitiesResponse;
      this.state.communities = data.communities;
      this.state.communities.sort(
        (a, b) => b.number_of_subscribers - a.number_of_subscribers
      );
      this.state.loading = false;
      window.scrollTo(0, 0);
      this.setState(this.state);
    } else if (res.op == UserOperation.FollowCommunity) {
      let data = res.data as CommunityResponse;
      let found = this.state.communities.find(c => c.id == data.community.id);
      found.subscribed = data.community.subscribed;
      found.number_of_subscribers = data.community.number_of_subscribers;
      this.setState(this.state);
    } else if (res.op == UserOperation.GetSite) {
      let data = res.data as GetSiteResponse;
      this.state.site = data.site;
      this.setState(this.state);
    }
  }
}