return this._dbPromise.then(function(db) {
    // if we're already showing posts, eg shift-refresh
    // or the very first load, there's no point fetching
    // posts from IDB
    if (!db || indexController._postsView.showingPosts()) return;

    // TODO: get all of the wittr message objects from indexeddb,
    // then pass them to:
    // indexController._postsView.addPosts(messages)
    // in order of date, starting with the latest.
    // Remember to return a promise that does all this,
    // so the websocket isn't opened until you're done!
    var tx = db.transaction('wittrs');
    var store = tx.objectStore('wittrs');
    var timeIndex = store.index('by-date');

    return timeIndex.getAll();
  }).then(function(messages) {
    indexController._postsView.addPosts(messages);
  });