var store = new Ext.data.JsonStore({ id:\'jfields\', totalProperty:\'totalcount\', root:\'rows\', url: \'data.php\', fields:[{ name:\'jfields\' },
See the recordType property in the JsonStore. It's a function that can be used as a record constructor for the store in question. Use it like this:
recordType
var newRecord = new myStore.recordType(recordData, recordId); myStore.add(newRecord);