session-desktop/js/views/group_update_view.js

(function() {
  'use strict';

  window.Whisper = window.Whisper || {};

  Whisper.GroupUpdateView = Backbone.View.extend({
    tagName: 'div',
    className: 'group-update',
    render: function() {
      //TODO l10n
      if (this.model.left) {
        this.$el.text(this.model.left + ' left the group');
        return this;
      }

      var messages = ['Updated the group.'];
      if (this.model.name) {
        messages.push("Title is now '" + this.model.name + "'.");
      }
      if (this.model.joined) {
        messages.push(this.model.joined.join(', ') + ' joined the group');
      }

      this.$el.text(messages.join(' '));

      return this;
    },
  });
})();