Development-Custom Error Handling

Version 9.1 by Ray Kiddy on 2021/04/22 20:40
Warning
For security reasons, the document is displayed in restricted mode as it is not the current version. There may be differences and errors due to this.

Exception Page

To provide a custom error handler when an exception is thrown, override this WOApplication method:


public WOResponse handleException (java.lang.Exception anException, WOContext aContext) { }

For example:


public WOResponse handleException(Exception _exception, WOContext _context) {
 Session session = (Session) _context.session();
 // do something to notify user of exception, maybe put a message in the session here ...
 WOResponse response;
 if (/* you can't handle exception*/) {
   response = super.handleException(_exception, _context);
  }
 else {
   response = pageWithName(YourExceptionPage.class.getName(), _context).generateResponse();
  }
 return response;
}

Session Expired

To provide a custom error handler when an exception is thrown, override the method:


public WOResponse handleSessionRestorationErrorInContext(WOContext _context) {

For example:


public WOResponse handleSessionRestorationErrorInContext(WOContext _context) {
 Session session = (Session) _context.session();
 // do something to notify user of exception, maybe put a message in the session here ...
 WOResponse response = pageWithName(YourErrorPage.class.getName(), _context).generateResponse();
 return response;
}

Your Request Produced an Error

Chuck Hill

This message started to appear in WO 5.2 when an exception was raised in a DirectAction, but only in deployed applications. Here is what is happening:

WODisplayExceptionPages
true or false to enable or disable the generation of WOExceptionPages for direct action requests. Default is true in development mode and false in deployment mode.

FromĀ https://developer.apple.com/library/archive/documentation/WebObjects/WOAppProperties/Articles/ApplicationProperties.html#//apple_ref/doc/uid/TP40005337-SW1

If the page being returned throws during appendToResponse and the app is deployed, all that is displayed is a blank page with the words "Your request produced an error".

To avoid this, either add this to the launch agruments:

Unknown macro: noformat. Click on this message for details.

Or change the main method in your Application class to look like this:


public static void main(String argv[]) {
 System.setProperty("WODisplayExceptionPages", "true");
  WOApplication.main(argv, Application.class);
}

This won't work if you put it in the constructor.