Agreed, good point. > On 30 Sep 2015, at 3:34 am, Thiago H de Paula Figueiredo <thiag...@gmail.com> > wrote: > > Hi! > > Very nice point. Could you please create a JIRA issue? > > On Tue, 29 Sep 2015 13:55:10 -0300, Cezary Biernacki <cezary...@gmail.com> > wrote: > >> Hi, >> >> Some introduction: My users started complaining about error message "Forms >> require that the request method be POST and that the t:formdata query >> parameter have values.". I understand why it was raised: Tapestry 5's Form >> component always used to complain when submit was invoked as GET operations >> (e.g. somebody typed "http://host/mypage.myform"; URL directly in the >> address bar) . Pre-5.4 it was not big issue, because it was rather unusual >> to users to accidentally invoke submit URL as GET operations, as Tapestry >> always used Redirect-After-POST approach, and submit URLs typically were >> not saved by browsers in the history. However Tapestry 5.4 does not >> redirect after POST in case of server-side validation errors on submitted >> forms (e.g. password checking). IIRC, this change was introduced to avoid >> unnecessary creation of server side sessions. >> >> Again, I understand that. But now submit URLs are often exposed address bar >> (e.g. every time a user makes mistake entering password), stored in the >> browser's history, and - most importantly - suggested by browsers when >> users start typing the application address. I believe such behaviour leads >> to bad usability and leaves unpleasant impression of Tapestry's >> application. As far as I can tell there is no simple work around to avoid >> the exception (beside totally rewriting Form component). Only way I found >> that works reasonably well is to suppress the exception in >> RequestExceptionHandler and perform some other action - in my case: >> redirect to the page - see code below. >> >> However detecting this particular exception is tricky as it is just generic >> RuntimeException (why?) and the message content is localised >> (see org.apache.tapestry5.corelib.components.Form#executeStoredActions - >> around line 700 >> https://github.com/apache/tapestry-5/blob/master/tapestry-core/src/main/java/org/apache/tapestry5/corelib/components/Form.java#L701), >> so detecting is quite fragile. >> >> My questions: >> - do you know any better way to deal with this problem? >> - do you see any potential issues with my solution? >> >> And appeal to Tapestry's creators: please introduce a more specific >> exception class and/or allow application developers to supply their own >> strategy dealing with such situation. >> >> Best regards, >> Cezary >> >> >> >> // skipped header (imports etc.)... >> >> public class FormPostProblemWorkaroundExceptionHandler implements >> RequestExceptionHandler { >> >> private static final Logger LOGGER = LoggerFactory.getLogger >> (FormPostProblemWorkaroundExceptionHandler.class); >> >> private final RequestExceptionHandler delegate; >> >> private final RequestGlobals requestGlobals; >> >> private final BaseURLSource baseURLSource; >> >> private final PageRenderLinkSource pageRenderLinkSource; >> >> >> public FormPostProblemWorkaroundExceptionHandler( >> final RequestExceptionHandler delegate, >> final RequestGlobals requestGlobals, >> final BaseURLSource baseURLSource, >> final PageRenderLinkSource pageRenderLinkSource >> ) { >> this.delegate = delegate; >> this.requestGlobals = requestGlobals; >> this.baseURLSource = baseURLSource; >> this.pageRenderLinkSource = pageRenderLinkSource; >> } >> >> @Override >> public void handleRequestException(final Throwable exception) throws >> IOException >> { >> if (isExceptionAboutFormExpectingPostMethod(exception)) { >> redirect(exception); >> return; >> } >> >> delegate.handleRequestException(exception); >> } >> >> private boolean isExceptionAboutFormExpectingPostMethod(final Throwable >> exception) { >> // unfortunately, original exception is just RuntimeException and its >> message is localised >> // (see Tapestry message ID core-invalid-form-request), only constant >> information is reference to t:formdata argument >> // see org.apache.tapestry5.corelib.components.Form.executeStoredActions() >> return exception instanceof OperationException >> && exception.getCause() instanceof ComponentEventException >> && exception.getMessage().contains(Form.FORM_DATA); >> } >> >> private void redirect(final Throwable exception) throws IOException { >> >> final Request request = requestGlobals.getRequest(); >> final String failurePage = (request.getAttribute(InternalConstants. >> ACTIVE_PAGE_LOADED) == null) >> ? null >> : requestGlobals.getActivePageName(); >> >> final Response response = requestGlobals.getResponse(); >> >> if (failurePage == null) { >> final String rootURL = baseURLSource.getBaseURL(request.isSecure()); >> LOGGER.info("Redirecting to root URL {} after '{}'", rootURL, >> exception.getMessage()); >> response.sendRedirect(rootURL); >> return; >> } >> >> final Link link = pageRenderLinkSource.createPageRenderLink(failurePage); >> LOGGER.info("Redirecting to page {} after '{}'", link, >> exception.getMessage()); >> response.sendRedirect(link); >> >> } >> } >> >> // add this method in your AppModule class >> >> @Decorate(serviceInterface = RequestExceptionHandler.class) >> public static RequestExceptionHandler installWorkaroundForFormPOSTProblem( >> @Nonnull final RequestExceptionHandler delegate, >> @Nonnull final RequestGlobals requestGlobals, >> @Nonnull final BaseURLSource baseURLSource, >> @Nonnull final PageRenderLinkSource pageRenderLinkSource >> ) { >> return new FormPostProblemWorkaroundExceptionHandler(delegate, >> requestGlobals, baseURLSource, pageRenderLinkSource); >> } > > > -- > Thiago H. de Paula Figueiredo > Tapestry, Java and Hibernate consultant and developer > http://machina.com.br > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tapestry.apache.org > For additional commands, e-mail: users-h...@tapestry.apache.org >
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