Move DiscussionListState to correct folder

js/src/forum/states/DiscussionListState.js

@@ -0,0 +1,190 @@
+export default class DiscussionListState {
+  constructor({ params = {}, forumApp = app } = {}) {
+    this.params = params;
+
+    this.app = forumApp;
+
+    this.discussions = [];
+
+    this.moreResults = false;
+
+    this.loading = false;
+  }
+
+  /**
+   * Get the parameters that should be passed in the API request to get
+   * discussion results.
+   *
+   * @api
+   */
+  requestParams() {
+    const params = { include: ['user', 'lastPostedUser'], filter: {} };
+
+    params.sort = this.sortMap()[this.params.sort];
+
+    if (this.params.q) {
+      params.filter.q = this.params.q;
+
+      params.include.push('mostRelevantPost', 'mostRelevantPost.user');
+    }
+
+    return params;
+  }
+
+  /**
+   * Get a map of sort keys (which appear in the URL, and are used for
+   * translation) to the API sort value that they represent.
+   */
+  sortMap() {
+    const map = {};
+
+    if (this.params.q) {
+      map.relevance = '';
+    }
+    map.latest = '-lastPostedAt';
+    map.top = '-commentCount';
+    map.newest = '-createdAt';
+    map.oldest = 'createdAt';
+
+    return map;
+  }
+
+  /**
+   * Get the search parameters.
+   */
+  getParams() {
+    return this.params;
+  }
+
+  /**
+   * Clear cached discussions.
+   */
+  clear() {
+    this.discussions = [];
+    m.redraw();
+  }
+
+  /**
+   * If there are no cached discussions or the new params differ from the
+   * old ones, update params and refresh the discussion list from the database.
+   */
+  refreshParams(newParams) {
+    if (!this.hasDiscussions() || Object.keys(newParams).some((key) => this.getParams()[key] !== newParams[key])) {
+      this.params = newParams;
+
+      this.refresh();
+    }
+  }
+
+  /**
+   * Clear and reload the discussion list.
+   */
+  refresh({ clear = true } = {}) {
+    this.loading = true;
+
+    if (clear) {
+      this.clear();
+    }
+
+    return this.loadResults().then(
+      (results) => {
+        this.parseResults(results);
+      },
+      () => {
+        this.loading = false;
+        m.redraw();
+      }
+    );
+  }
+
+  /**
+   * Load a new page of discussion results.
+   *
+   * @param offset The index to start the page at.
+   */
+  loadResults(offset) {
+    const preloadedDiscussions = this.app.preloadedApiDocument();
+
+    if (preloadedDiscussions) {
+      return Promise.resolve(preloadedDiscussions);
+    }
+
+    const params = this.requestParams();
+    params.page = { offset };
+    params.include = params.include.join(',');
+
+    return this.app.store.find('discussions', params);
+  }
+
+  /**
+   * Load the next page of discussion results.
+   */
+  loadMore() {
+    this.loading = true;
+
+    this.loadResults(this.discussions.length).then(this.parseResults.bind(this));
+  }
+
+  /**
+   * Parse results and append them to the discussion list.
+   */
+  parseResults(results) {
+    this.discussions.push(...results);
+
+    this.loading = false;
+    this.moreResults = !!results.payload.links && !!results.payload.links.next;
+
+    m.redraw();
+
+    return results;
+  }
+
+  /**
+   * Remove a discussion from the list if it is present.
+   */
+  removeDiscussion(discussion) {
+    const index = this.discussions.indexOf(discussion);
+
+    if (index !== -1) {
+      this.discussions.splice(index, 1);
+    }
+
+    m.redraw();
+  }
+
+  /**
+   * Add a discussion to the top of the list.
+   */
+  addDiscussion(discussion) {
+    this.discussions.unshift(discussion);
+    m.redraw();
+  }
+
+  /**
+   * Are there discussions stored in the discussion list state?
+   */
+  hasDiscussions() {
+    return this.discussions.length > 0;
+  }
+
+  /**
+   * Are discussions currently being loaded?
+   */
+  isLoading() {
+    return this.loading;
+  }
+
+  /**
+   * In the last request, has the user searched for a discussion?
+   */
+  isSearchResults() {
+    return !!this.params.q;
+  }
+
+  /**
+   * Have the search results come up empty?
+   */
+  empty() {
+    return !this.hasDiscussions() && !this.isLoading();
+  }
+}