discourse/app/assets/javascripts/discourse/routes/build-group-messages-route.js.es6

import UserTopicListRoute from "discourse/routes/user-topic-list";

export default (type) => {
  return UserTopicListRoute.extend({
    titleToken() {
      return I18n.t(`user.messages.${type}`);
    },

    model() {
      const groupName = this.modelFor('group').get('name');
      const username = this.currentUser.get("username_lower");
      let filter = `topics/private-messages-group/${username}/${groupName}`;
      if (this._isArchive()) filter = `${filter}/archive`;
      return this.store.findFiltered("topicList", { filter });
    },

    setupController() {
      this._super.apply(this, arguments);

      const groupName = this.modelFor('group').get('name');
      let channel = `/private-messages/group/${groupName}`;
      if (this._isArchive()) channel = `${channel}/archive`;
      this.controllerFor("user-topics-list").subscribe(channel);

      this.controllerFor("user-topics-list").setProperties({
        hideCategory: true,
        showPosters: true
      });
    },

    _isArchive() {
      return type === 'archive';
    },
  });
};