lib/Ext/dataview/NestedList.js
function () {
        var me = this,
            node = me.getLastNode(),
            detailCard = me.getDetailCard(),
            detailCardActive = detailCard && me.getActiveItem() == detailCard,
            lastActiveList = me.getLastActiveList();

        this.fireAction('back', [this, node, lastActiveList, detailCardActive], 'doBack');
    }
function () {
        var me = this,
            node = me.getLastNode(),
            detailCard = me.getDetailCard(),
            detailCardActive = detailCard && me.getActiveItem() == detailCard,
            lastActiveList = me.getLastActiveList();

        this.fireAction('back', [this, node, lastActiveList, detailCardActive], 'doBack');
    }
Called when the backButton has been tapped.