Dear Sir or Madam,
we having a specific problem in using Wicket 7.10, creating an Ajax-Response
with multiple <ajax-response> entries.
In our application, we are using onRequestHandlerResolved to do some
initialization stuff and onRequestHandlerExecuted to save changes done on our
data during requestHandlerExecutor.execute().
For this purpose, we have created an own AbstractRequestCycleListener which
overwrites both methods and calls our specific code.
RequestCycle:
private void execute(IRequestHandler handler)
{
try
{
listeners.onRequestHandlerResolved(this, handler);
requestHandlerExecutor.execute(handler);
listeners.onRequestHandlerExecuted(this, handler);
}
catch (RuntimeException e)
{
}
}
Our problem is, that an Exception thrown in onRequestHandlerExecuted after
requestHandlerExecutor.execute() has already created an ajax-response creates
an invalid response:
Wicket.Ajax: Wicket.Ajax.Call.failure: Error while parsing response: Error:
Invalid XML: <?xml version="1.0" encoding="UTF-8"?>
<ajax-response>
<!-- Result of requestHandlerExecutor.execute() -->
</ajax-response>
<ajax-response>
<!-Redirect to specific Exception Page, result of
onRequestHandlerExecuted -->
<redirect>
<![CDATA[./wicket/bookmarkable/our.package.ExceptionPage?locale=en]]>
</redirect>
</ajax-response>
To solve our problem, we tried to clear the existing Response during exception
in onRequestHandlerExecuted (RequestCycle.get().getResponse().reset()), but we
are not able to clear the Response, created in
requestHandlerExecutor.execute(), because wicket uses
HeaderBufferingWebResponse by default which did not allow to reset already
created Response in encapsulated ServletWebResponse. Calling reset in
HeaderBufferingWebResponse instead throws an IllegalStateException.
We think that the problem came from ServletWebResponse which simply adds
multiple ajax-response entries to the HttpServletResponse which results in the
mentioned, invalid XML.
ServletWebResponse:
@Override
public void sendRedirect(String url)
{
try
{
if (webRequest.isAjax())
{
/*
* usually the Ajax-Location header is enough and we do not need to the
redirect url
* into the response, but sometimes the response is processed via an iframe
(eg
* using multipart ajax handling) and the headers are not available because
XHR is
* not used and that is the only way javascript has access to response
headers.
*/
httpServletResponse.getWriter().write(
"<ajax-response><redirect><![CDATA[" + url +
"]]></redirect></ajax-response>");
}
else { }
}
catch (IOException e) { }
}
My question is, how we could handle our problem when throwing an exception in
onRequestHandlerExecuted? And how is it possible, that code run after
requestHandlerExecutor.execute(), redirects correctly to exception page?
How we can run specific code, after the request has been processed, is there
maybe another way instead of overwriting onRequestHandlerExecuted?
Kind regards
PATRICK SCHWARZER
SOFTWARE ENGINEER
o +49 89 32175 655
TOMTEC Imaging Systems GmbH
Edisonstrasse 6, 85716 Unterschleissheim, Germany, Managing Director:
Johannes Waldinger, Dr. Thomas Piehler, HRB 235646 Amtsgericht Muenchen
[cid:[email protected]]<http://www.tomtec.de/>
_____________________________________________________________
RSNA | 11/25/2018 - 11/30/2018 | Chicago/USA
EuroEcho | 12/05/2018 - 12/08/2018 | Milan/Italy
