Developing Mobile…Force.com and Sencha-Part 3, Step 3: Repair the error listener code

flawed code

//THIS IS THE FLAWED CODE!
//Listen for exceptions observed by the proxy so we can report them and clean up.
Ext.getStore('Leads').getProxy().addListener('exception', function (proxy, response, operation, options) {
    // only certain kinds of errors seem to have useful information returned from the server
    if (response.data) {
        if (response.data.errorMessage) {
            Ext.Msg.alert('Error', response.data.errorMessage);
        } else {
            Ext.Msg.alert('Error', operation.action + ' failed: ' + response.data.message);
        }
    } else {
        Ext.Msg.alert('Error', operation.action + ' failed for an unknown reason');
    }
});

repaired code

//THIS IS THE REPAIRED CODE!
//Listen for exceptions observed by the proxy so we can report them and clean up.
Ext.getStore('Leads').getProxy().addListener('exception', function (proxy, response, operation, options) {
    // only certain kinds of errors seem to have useful information returned from the server
    if (response) {
        if (response.errorMessage) {
            Ext.Msg.alert('Error', response.errorMessage);
        } else {
            Ext.Msg.alert('Error', operation.config.action + ' failed: ' + response.errorMessage);
        }
    } else {
        Ext.Msg.alert('Error', operation.config.action + ' failed for an unknown reason');
    }
});