CustomConstraint (ZK XUL Components 10.3.0.FL.202601081520 API)

```
public interface CustomConstraint
```
Additional interface implemented with Constraint to denote a constraint supports a custom way to display the error message. If this interface is implemented, the default error box won't be displayed. Rather, showCustomError(org.zkoss.zk.ui.Component, org.zkoss.zk.ui.WrongValueException) is called.
Since 5.0.0, CustomConstraint has the higher priority than ClientConstraint. In other words, ClientConstraint is ignored if both defined. On the other hand, the client validation object (ClientConstraint.getClientConstraint()) can implement the showCustomError method to do the similar job at the client.

Author:

tomyeh

See Also:

Constraint, ClientConstraint

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`showCustomError(org.zkoss.zk.ui.Component comp, org.zkoss.zk.ui.WrongValueException ex)`	To display the error message in a custom way.

- Method Detail
  - showCustomError
```
void showCustomError(org.zkoss.zk.ui.Component comp,
                     org.zkoss.zk.ui.WrongValueException ex)
```
    To display the error message in a custom way. Note: this method is called either with a error or not, depending on whether ex is null.
    
    Parameters:
    
    comp - the component causing the error.
    
    ex - the error to display, or null to clear the error message.