[Seaside-dev] exception handler instance creation

[Julian Fitzell]

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

On Wed, Dec 31, 2008 at 8:28 PM, John O'Keefe
<wembley.instantiations at gmail.com> wrote:
> Julian -
> I'm back to work after a week and got a bad surprise.
> Seaside-Core-jf.349 and the associated changes to other packages has
> completely broken the VA Smalltalk port.  Our implementation of
> Block>>#on:do: expects a class as its first argument (and in particular, the
> class must be Exception or a subclass of Exception).  The same seems to be
> true of VW.
>
> But with Seaside-Core-jf.349 #on:do: is getting a WAExceptionHandler class
> (or subclass of it) as the first argument <exception selector> and then with
> Seaside-Core-jf.353 #on:do: is getting an instance of WAExceptionHandler (or
> a subclass of it) as the first argument.  In either case, we fall over
> because the WAExceptionHandler class/instance does not understand any of the
> messages sent by #on:do: to the <exception selector>.
> Since WAExceptionHandler is in the base, I assume it should be portable.
> I have reverted to Seaside-Core-lr.348 and Seaside-Development-lr.53 for the
> time being and things seem to be working OK again.
> John O'Keefe [|], Principal Smalltalk Architect, Instantiations Inc.