Sencha 2.4.1 - List Not Displaying Items

Question

I am trying to populate a list with static data in store, using Sencha touch 2.4.1.

One main view contains the titlebar and the list. The list is trying to get the data from the store based model, Employee.

Following are the code snippets, I cannot find out where I am getting it wrong.

Employee List View

Ext.define('MyApp.view.EmpList',{
    extend: 'Ext.List',
    xtype: 'emp_list',
    config:{
         itemTpl: Ext.XTemplate('<span>{firstname}</span>')
    }
});

Employee Store

Ext.define('MyApp.store.Employee',{
extend: 'Ext.data.Store',
config:{
    storeId: 'emp_store',
    model: 'MyApp.model.Employee',
    emptyText: 'No Employees Yet!',
    data:[
        {firstname:'Danish', lastname:'Siddiqui', ranking:'1', is_manager:false},
        {firstname:'Danish', lastname:'Siddiqui1', ranking:'2', is_manager:false},
        {firstname:'Danish', lastname:'Siddiqui2', ranking:'3', is_manager:false},
        {firstname:'Danish', lastname:'Siddiqui3', ranking:'4', is_manager:false},
    ]
}

});

Employee Model

Ext.define('MyApp.model.Employee',{
extend: 'Ext.data.Model',
config: {
    fields:[
        {name: 'firstname',     type:'string'},
        {name: 'lastname',      type:'string'},
        {name: 'ranking',       type:'number'},
        {name: 'is_manager',    type:'boolean', defaultValue: false}
    ]
}

});

Main View

Ext.define('MyApp.view.Main', {
extend: 'Ext.Container',
xtype: 'main',
requires:[
    'Ext.TitleBar'
],
config: {
    items: [
        {
            xtype: 'titlebar',
            title: 'Employe Information',
            items:[
                {
                    xtype: 'button',
                    ui: 'back',
                    text: 'back'
                }
            ]
        },
        {
            xtype: 'emp_list',
            store: 'emp_store'
        }
    ]

}
});

Answer 1

setting width and height properties of list works.

config:{
    width: '100%',
    height: '100%',
    itemTpl: Ext.XTemplate('<span>{firstname} &nbsp; {lastname}</span>'),
    store: 'emp_store'
}