Sencha Touch MVC issues: Uncaught TypeError: Object function (){ superclass.apply(this, arguments); } has no method 'setActiveItem'

I've got a list view that extends panel, and I define a listener for an itemtap event that does an Ext.dispatch to my controller, that I basically want to set my form view as active. In my cont开发者_运维问答roller's action, the method looks like this:

itemTap : function(dataObj) {
    var views = dataObj.views,
    contactForm = views.contactForm,
    model = dataObj.model;
    console.log(dataObj);

    contactForm.loadRecord(model);

    this.application.Viewport.setActiveItem(contactForm, {type:'slide', direction:'right'});
}

I get an error on my last line of this action: Uncaught TypeError: Object function (){ superclass.apply(this, arguments); } has no method 'setActiveItem' and I'm having a hard time deciphering this error message. What am I doing wrong?