Sencha Touch Back Button Plugin

back.js

BackButton = Ext.extend(Ext.Button, {
    ui: 'back', 
    text: 'Back', 
    hidden: true, 
    id: 'back',

    handler: function() {
        var dispatchOptions = this.backStack.pop();
        Ext.dispatch(dispatchOptions);
        if(this.backStack.length == 0) {
            this.hide();
        }
    },

    backStack: [],

    addToBackStack: function(dispatchOptions) {
        var found = false;
        this.backStack.forEach(function(el) {
            found = found || (Ext.encode(el) == Ext.encode(dispatchOptions));
        });
        if (!found) {
            this.backStack.push(dispatchOptions);
        }
        this.show();
    },

    clearBackStack: function() {
        this.backStack = [];
        this.hide();
    }
});