Getters on Models

The convert method of a model field is called when a value is set, not read, which is kinda bass-ackwards.

It is also called when a model is constructed, and before any associations are loaded, meaning you shouldn't be using it as a pseudo-getter, which I've seen recommended elsewhere.

Here's how to make a virtual field on a model:

Ext.define('My.model.Contact', {
  extend:'Ext.data.Model',

  getfull_name: function(){
    return this.get('first_name') + ' ' + this.get('last_name');
  },

  fields:[
    'first_name',
    'last_name'
  ],

  /* override Model.get */
  get: function(field){
    if(this['get'+field]) return this['get'+field](); //if get<field> exists, call it
    else return this.callParent(arguments); //otherwise, use regular get
  }
});

Usage:

var contact = Ext.create('My.model.Contact');
contact.set('first_name');
contact.set('last_name');

console.log(contact.get('full_name'));.