[Seaside-dev] exception handler instance creation

[Dale Henrichs]

----- "Julian Fitzell" <jfitzell at gmail.com> wrote:

| Hi John,
| 
| Darn... I was following the ANSI standard... ;) it says that an
| exception selector needs to implement #handles: and #, which we do on
| both the class and instance side. On most systems this would include
| the Exception class and instances of ExceptionSet. How does VA
| implement ExceptionSet if #on:do: is so restrictive?
| 
| Lukas took a quick look at his VA image and says it looks like
| WAExceptionHandler might just need an implementation of #handles:do:
| added in the VA port but I don't have a Windows install handy to look
| myself. I added some tests in Seaside-Tests-Core-jf.32 that should
| help verify directly if it's working or not, though.
| 
| Do you think it's a solvable problem on VA? I just looked at VW and
| it
| looks like they would need to implement #isExceptionHandler in their
| compatibility package.
| 
| Dale, I haven't got Gemstone installed on this new laptop yet either.
| Do you foresee problems getting this to work on your end?
| 
| Obviously if this is going to be a huge compatibility problem we
| should rethink but I think the implementation is cleaner this way
| otherwise.
| 
| Julian

Julian,

For the exception handling to work correctly in GemStone, we also need to have subclasses of Exception (ExceptionA in 2.x and in 3.x Exception). There's a fair amount of support code in Exception that is inherited and is needed for exceptions to work correctly. 

James Foster is very intimate with the 2.x exception handling mechanism and has been working with Seaside2.9 recently, so he can give a definitive answer.

Dale