Question

I have a component with a custom model (extending the wicket standard Model class). My model loads the data from a database/web service when Wicket calls getObject().

This lookup can fail for several reasons. I’d like to handle this error by displaying a nice message on the web page with the component. What is the best way to do that?

public class MyCustomModel extends Model {

    @Override
    public String getObject() {
        try {
            return Order.lookupOrderDataFromRemoteService();
        } catch (Exception e) {
            logger.error("Failed silently...");
            // How do I propagate this to the component/page?
        }           
        return null;
}

Note that the error happens inside the Model which is decoupled from the components.

Answer 1

Your model could implement IComponentAssignedModel, thus being able to get hold on the owning component.

But I wonder how often are you able to reuse MyCustomModel?
I know that some devs advocate creating standalone model implementations (often in separate packages). While there are general cases where this is useful (e.g. FeedbackMessagesModel), in my experience its easier to just create inner classes which are component specific.