Ext.define('IW.model.Lock', { extend: 'Ext.data.Model', fields: [ { name: 'id', type: 'string', convert: function(value, record) { return record.get('Wiki_id')+'/'+record.get('Target_id'); } }, 'Target_id', 'Wiki_id', 'Username', 'Realname', 'Modified', ], idProperty: 'id', proxy: { type: 'rest', url: '/api/locks/', reader: { type: 'json', successProperty: 'success' } } });