[Seaside] Computation has been terminated - error is back

[Derek Brans]

Avi,
Nevermind, the error is back.  Nothing changed to make the error come 
back, though.  I definitely think that the problem is in my code cause 
when I load the code in another image it does the same thing.

Back to square one.  Things I've changed: I've subclassed WASession to 
handle 'unknownRequest' and also 'longUniqueKey'.
The latter might warrant some attention:
longUniqueKey
	"ensure uniqueness even across sessions"
	^ response useCookies
		ifTrue: [sessionKey, '-', self uniqueKey]
		ifFalse: [self uniqueKey]

This is the WASession implementation.  However, there's a bug in that 
code cause when using cookies I've found that sometimes sessionKey is 
nil.  So I subclassed it to check for sessionKey being nil.

XESession>>longUniqueKey
	"ensure uniqueness even across sessions"
	^ (response useCookies and: [sessionKey notNil])
		ifTrue: [sessionKey, '-', self uniqueKey]
		ifFalse: [self uniqueKey]

But that change I made eons ago and never got any complaints from the 
system.  So that might not be it.  But it's a bug you might want to look 
into.  I don't know if that's the most graceful way to handle it.

Can you tell me more about how a request would accidentally get handled 
twice?  I subclassed WARequest but that was only to handle url parsing 
differently.

Thanks,
Derek








On Monday, January 13, 2003, at 12:31 PM, Derek Brans wrote:

> Avi, thanks for your reply.
>
> I did some hunting around and noticed that I overrode "initialize" on 
> the class side in one of my entryPoint components.  I added "super 
> initialize" and the application seems to be working now.  Would that 
> mistake account for the error I was seeing?
>
> Why does WAComponent>>initialize recompile all its subclasses?
>
> Thanks again,
>
> Derek
>
>
>
> On Monday, January 13, 2003, at 11:57 AM, Avi Bryant wrote:
>
>>
>> Derek,
>>
>> At the point that a session is asked to handle a request, it captures 
>> the
>> current continuation and stores it in the instance variable 'shortJmp'
>> (which should now probably be renamed to something like 
>> 'escapeRequest').
>> Whenever the response is finished, it invokes this continuation using
>> #oneShotValue, and #handleRequest: returns.
>>
>> The point of #oneShotValue is that it can only be invoked once - which 
>> is
>> what we want here, since for each request there can only be one 
>> response.
>> If you try to invoke a continuation with #oneShotValue twice (ie, if 
>> you
>> try to respond twice to the same request), you will get the 
>> "Computation
>> has been terminated" error.  Essentially, you can interpret that error 
>> as
>> "you've been messing about in the guts of Session and are violating 
>> some
>> essential invariant it depends on".
>>
>> What does your custom Session subclass actually do?
>>
>>  On Sat, 11 Jan 2003, Derek Brans wrote:
>>
>>> So, I'm getting a little error.
>>>
>>> The first page of my application loads fine, but when I click on any
>>> links I get the error:
>>>
>>> "Computation has been terminated"
>>>
>>> Method Context>>cannotReturn
>>> Continuation>>oneShotValue
>>> [] in XESession(WASession)>>handleRequest:response:
>>>
>>> Any ideas?
>>>
>>> Thanks,
>>> Derek
>>>
>>>
>>>
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Website Design - Database Systems - Site Hosting
604.874.6463
mailto:info@nerdonawire.com
For more information, visit http://nerdonawire.com