--- bob mcwhirter <[EMAIL PROTECTED]> wrote: > > Golly, does this break pretty much all existing > tags? > (bob scans his bazillion tags...)
Is this drools you're talking about? Yes, every tag that throws Exception will no longer compile against the HEAD of Jelly. Not desirable, I agree, but also unavoidable and specifically mentioned in the proposal made last Thursday: http://marc.theaimsgroup.com/?l=jakarta-commons-dev&m=104335501905419&w=2 > I don't really buy the style argument regarding > making it easier > for readers vs. authors of tags. I don't think this > is a place > to assert a particular dogma. I think it makes a difference some of in the non-trivial tags. > The issue, as I see it, is about error-handling. > Narrowing the > type thrown doesn't help me handle my exceptions at > all. Jelly doesn't > care about the type, one way or the other. > > As it stands now, you can certainly narrow the > exceptions your tags > throw. I can throw or handle whatever I want, > easily, without having > to handle exceptions I don't wish to handle, purely > to wrap. > > While now I can do the following and handle > MalformedURLExceptions > if I'm able to, and ignore anything I'm unable to > handle. > > public void doTag(XMLOutput output) throws Exception > { > URL url = null; > > try > { > url = new URL( whatever ); > } > catch (MalformedURLException e) > { > url = somethingElse(); > } > } > > Under the new code I'd have to do this: > > public void doTag(XMLOutput output) throws Exception > { > URL url = null; > > try > { > url = new URL( whatever ); > } > catch (MalformedURLException e) > { > url = somethingElse(); > } > catch (Exception e) > { > // a suspicious amount of handling for an > // unhandled exception... > throw new JellyException( e ); > } > } I'm not sure I understand your example. URL only throws one type of exception (MalformedURLException), which you are catching. What is the purpose of the catch(Exception) block? If your perception is that you need to introduce catch(Exception) blocks into all your methods for some reason, or that somehow Jelly is no longer equipped to handler RuntimeExceptions, that's not the case. I realize these changes create another requirement for other taglib authors. I have to weigh this against my belief that Jelly's internal implementations need compile-time verification that exceptions are accounted for and handled appropriately. > That's not pleasing. Arguing stylistically, I'd say > it even forces > me to inject noise or red-herrings into my code, > possibly confusing the > reader. "Hey, he's catching and handling all > exceptions" instead of > "Hey, he makes no claims about the unhandled > exceptions escaping > from this method." I think users understand what try/catch blocks mean. It's only confusing if you aren't picky about using them and scope whole method bodies with huge blocks. Yes, this means you have to handle exceptions. I don't want to force you to adopt a particular style, but I think the alternative leads to a bunch of undocumented exceptions in Jelly, and that I don't care for. It's tough to have it both ways. I think the redesign is a short term chore with long term benefits. If you truly view the old design as superior, however, it's probably simple to emulate in your own projects: public abstract class MyTagSupport extends TagSupport { public void doTag(XMLOutput output) throws JellyTagException { try { doMyTag(output); } catch (Exception e) { throw new JellyTagException(e); } } public abstract void doMyTag(XMLOutput output) throws Exception; } > If we had an official vote on this, I'd be close to > -1, hate to say. Which do you think is better, Jelly this week (no methods throwing generic Exceptions) or last week (all methods throwing Excecption). A veto means we go back to the old way, where all Exceptions that Jelly throws are completely undocumented. To me that's very undesirable. - Morgan > -bob > > > > On Tue, 28 Jan 2003, Morgan Delagrange wrote: > > > ...doTag() signature change stuff... > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: > [EMAIL PROTECTED] > For additional commands, e-mail: > [EMAIL PROTECTED] > ===== Morgan Delagrange http://jakarta.apache.org/taglibs http://jakarta.apache.org/commons http://axion.tigris.org http://jakarta.apache.org/watchdog __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
