discourse/app/assets/javascripts/discourse/controllers/group-activity-posts.js.es6

import { observes } from 'ember-addons/ember-computed-decorators';
import { fmt } from 'discourse/lib/computed';

export default Ember.Controller.extend({
  group: Ember.inject.controller(),
  groupActivity: Ember.inject.controller(),
  application: Ember.inject.controller(),
  canLoadMore: true,
  loading: false,
  emptyText: fmt('type', 'groups.empty.%@'),

  actions: {
    loadMore() {
      if (!this.get('canLoadMore')) { return; }
      if (this.get('loading')) { return; }
      this.set('loading', true);
      const posts = this.get('model');
      if (posts && posts.length) {
        const beforePostId = posts[posts.length-1].get('id');
        const group = this.get('group.model');

        let categoryId = this.get('groupActivity.category_id');
        const opts = { beforePostId, type: this.get('type'), categoryId };

        group.findPosts(opts).then(newPosts => {
          posts.addObjects(newPosts);
          if(newPosts.length === 0) {
            this.set('canLoadMore', false);
          }
        }).finally(() => {
          this.set('loading', false);
        });
      }
    }
  },

  @observes('canLoadMore')
  _showFooter() {
    this.set("application.showFooter", !this.get("canLoadMore"));
  }
});