Extjs 4.x Tips and Tricks

I will try to add few points  based on my experience in extjs 4.x.

• Communication between different controller.(use fireEvent on application)

this.fireEvent('expand', this, cmp, e);

• Lazy initialization of controller.

someAction: function() {
    var controller = this.getController('AnotherController');
 
    // Remember to call the init method manually
    controller.init();
}

• Avoid "Id" in coding for reusable component

Don't put id to components, Add id to where it use in your code 

{
  xtype:'customercombo',
  id:'cust-project-field-cust-name'
}

• Avoid using Ext.getCmp()..use Ext.ComponentQuery  
• Minimize no of panel in application.
• Avoid using ownerCt proprety
• Reduce container nesting
• Reduce border layout nesting
• Try to reuse the code
• Make a cleaner separation between model,view and controller

Only put static code in view and event code in controller and model to store the data

• Replace Panels with Containers

Panel is more expensive than contaier. Declare   xtype: 'container'  to avoid default panel.

{
 xtype: 'container', // defaultType is 'panel'
 items: [ ... ]
}