Unable to use when loading objects from store

gistfile1.js

App.actionsController = Em.ArrayController.create({
  content: [],
  sort: function() {
    var array, newArray;
    array = this.get('content').toArray();
    newArray = array.sort(function(a, b) {
      var a_due, a_isdone, a_isstarred, b_due, b_isdone, b_isstarred;
      a_isdone = a.get('isDone') ? 1 : 0;
      b_isdone = b.get('isDone') ? 1 : 0;
      a_isstarred = a.get('isStarred') ? 1 : 0;
      b_isstarred = b.get('isStarred') ? 1 : 0;
      a_due = a.get('due_at');
      b_due = b.get('due_at');
      if (a_isdone === b_isdone) {
        if (a_isstarred === b_isstarred) {
          if (a_due === b_due) {
            return 0;
          } else {
            if (a_due < b_due) {
              return -1;
            } else {
              return 1;
            }
          }
        } else {
          return b_isstarred - a_isstarred;
        }
      } else {
        return a_isdone - b_isdone;
      }
    });
    return this.set('content', newArray);
  },
  loadBlock: function(idNum) {
    this.set('content', App.store.find(App.ActionItem, {issue_id: idNum}));
    return this.sort();
  },
  toggleStar: function(action) {
    var starredSetting;
    starredSetting = !action.get('isStarred');
    action.set('isStarred', starredSetting);
    return this.sort();
  },
  toggleDone: function(action) {
    var doneSetting;
    doneSetting = !action.get('isDone');
    action.set('isDone', doneSetting);
    return this.sort();
  }
});