Wicket DateTextField custom error message - wicket

Question

I am using DateTextField for edit date field,
if user enter invalid date (eg. enter any character inseated of date)
then in on submit form DateTextField internally create invalid date message based on id.
My code is :
form.add(DateTextField.forDatePattern("orderStartDate", new DateModel(new PropertyModel<Date>(this, "defaultModelObject.startDate")), "dd/MM/yyyy"));
Now if a user enters any invalid date then in form submit, DateTextField generates the message.
"The value of 'orderStartDate' is not a valid Date."
In message 'orderStartDate' is id which i set on DateTextField;
Now I want to create custom message for this error inseated of above message;

Answer 1

The default value comes from IConverter resource bundle key: https://github.com/apache/wicket/blob/77b4df63f44d00e9350068686e4b091f730f167f/wicket-core/src/main/java/org/apache/wicket/Application.properties#L16
You need to provide a more specific one in YourApplication.properties to override it, e.g.:
orderStartDate.IConverter=Please provide a date with pattern dd/MM/yyyy.

Answer 2

The Validators usually report their class into the Error object. When Wicket generates the FeedbackMessage, it looks it up in the StringResourceModel. So if you use .properties or .properties.xml files for wording, you might want to add the FeedbackMessage using the key of IConverter (which reported the error)
<entry key="IConverter.Date">Please use the format dd/MM/yyyy!</entry>
Same story for required FormComponents
<entry key="Required">Please provide a value!</entry>
If you some day write your own validator, give it a key and optional parameters.
private void error(IValidatable<String> validatable) {
ValidationError error = new ValidationError();
error.addKey("id.exists");
error.setVariable("id", valueThatIsNotValid); // variable held in class
ekpCmp.error(error);
}
and define the StringResource
<entry key="id.exists">The value ${id} already exists.</entry>