[TAPESTRY-1823] It is not possible to create a reasonable implementation of RequestExceptionHandler without importing internal interfaces and services

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 5.0.5
• Fix Version/s: 5.0.8
• Component/s: tapestry-core
• Assignee: Howard Lewis Ship
• Reporter: Howard Lewis Ship
• Created: 13/Oct/07 00:04
• Updated: 07/Jan/08 18:56
• Resolved: 07/Jan/08 18:56

Description

It's not just a case of making the necessary interfaces public, but of providing public wrappers that ... for instance ... reference a page by name rather than as a Page instance (an internal type that should stay that way).

here's an example:

import java.io.IOException;

import org.apache.commons.logging.Log;
import org.apache.tapestry.Link;
import org.apache.tapestry.internal.services.LinkFactory;
import org.apache.tapestry.services.RequestExceptionHandler;
import org.apache.tapestry.services.Response;

public class ProductionRequestExceptionHandler implements RequestExceptionHandler {

private final Log _log;

private final LinkFactory _linkFactory;

private final Response _response;

public ProductionRequestExceptionHandler(Log log, LinkFactory linkFactory, Response response)

{ _log = log; _linkFactory = linkFactory; _response = response; }

public void handleRequestException(Throwable exception) throws IOException

{ _log.error("An exception has occurred: " + exception.getMessage(), exception); Link link = _linkFactory.createPageLink("AppError", false); _response.sendRedirect(link.toRedirectURI()); }

}

LinkFactory is internal. Even if it was promoted up, it includes Page which is internal.

Suggestion: create a public service, PageLinkFactory with method:

Link createPageLink(String pageName, boolean override, Object... activationContext)

that's a tiny, thin wrapper around the internal LinkFactory.

Something similar, for using a page to generate a direct response (rather than a redirect) might be nice, but is less urgent (exception generally occur during action requests, for which we should send a redirect).