Logout change view sencha touch

[koolll]

Hi I need to implement keep login in my sencha touch application
Please see my code below:
Login.js - Once user click login, it will store "sessionToken" in local storage.Then it will go to main Page

onBtnLoginClick: function(){

    
                var loginviewGetValue =  Ext.getCmp('loginview').getValues();
                var bbid =  Ext.getCmp('bbID').getValue();
                var bbpassword =  Ext.getCmp('bbPassword').getValue();
                    var LoginLS =   Ext.getStore('LoginLS');
    
    
    
    
    
                                        LoginLS.add({
                                            sessionId: 'sadsadsadasd'
                                           ,deviceId:'1'
                                           ,bb_id :bbid
                                           });
                                      
                                           LoginLS.sync();      
                                              
                                       var mainForm= Ext.create('bluebutton.view.Main');
                                        Ext.Viewport.setActiveItem(mainForm);

App.js~ Everytime launch function will check sessionToken in localStorage. If Localstorage is empty then it will go to login page.Else it will go to main Page

  launch: function() {

    
           
         
    
            // Destroy the #appLoadingIndicator element
            Ext.fly('appLoadingIndicator').destroy();
    
    
            // Initialize the main view
    
                 var LoginLS = Ext.getStore('LoginLS');
                 LoginLS.load();
    
                 var record =  LoginLS.getAt(0);
                    
    
                if(record != undefined){
                    var sessionId = record.get('sessionId');
                   if (sessionId !=undefined){
                         Ext.Viewport.add(Ext.create('bluebutton.view.Main'));
                   }
                   else
                       Ext.Viewport.add(Ext.create('bluebutton.view.Login'));
    
                }
                else{
                   Ext.Viewport.add(Ext.create('bluebutton.view.Login'));
                   }
    
    //        Ext.create('bluebutton.view.TopMenuList');
    
        },

Logout.js~Logout will clear the sessionToken and go to login page again

onLogoutClick: function scan() {

                    var LoginLS = Ext.getStore('LoginLS');
                    
                    
                         Ext.Viewport.setMasked({
                            xtype: 'loadmask',
                            message: 'Loading...'
                        });
    
                    
                    
                     LoginLS.load();
    
                     var record =  LoginLS.getAt(0);
                       LoginLS.removeAll();
                        LoginLS.sync();
                       //Load a new view
    
    
    //                   Ext.getCmp('tabpanel').destroy();
                   
                      
    
                   
    
    
                    var loginForm = Ext.create('bluebutton.view.Login');
                    Ext.Viewport.setActiveItem(loginForm);   
    
                    Ext.Viewport.setMasked(false); // hide the load screen

But i having a problem now. I not able to go back login page. It go to the blank page. Please give me some solution. Thanks.
Here is the error i get

 [WARN][Ext.data.Batch#runOperation] Your identifier generation strategy for the model does not ensure unique id's. Please use the UUID strategy, or implement your own identifier strategy with the flag isUnique. Console.js:35

    [WARN][Ext.Component#constructor] Registering a component with a id (`loginview`) which has already been used. Please ensure the existing component has been destroyed (`Ext.Component#destroy()`. Console.js:35
    [WARN][Ext.Component#constructor] Registering a component with a id (`bbID`) which has already been used. Please ensure the existing component has been destroyed (`Ext.Component#destroy()`. Console.js:35
    [WARN][Ext.Component#constructor] Registering a component with a id (`bbPassword`) which has already been used. Please ensure the existing component has been destroyed (`Ext.Component#destroy()`. Console.js:35
    [WARN][Ext.Component#constructor] Registering a component with a id (`btnLogin`) which has already been used. Please ensure the existing component has been destroyed (`Ext.Component#destroy()`. Console.js:35
    [DEPRECATE][bluebutton.view.Login#show] Call show() on a component that doesn't currently belong to any container. Please add it to the the Viewport first, i.e: Ext.Viewport.add(component);

[mitchellsimoens]

What does the model for the localstorage store look like?

I recommend against using the id config.