Re: Sitemap problem... help! :-)

[Sylvain Wallez]

Leszek Gawron wrote:
Sylvain Wallez wrote:
Mark Lundquist wrote:
OK, I figured out the problem (qv. 
http://marc.theaimsgroup.com/?t=110701945100004&r=1&w=2).

I had one matcher in the root sitemap that handled all continuation 
URIs, even those that are generated from pipelines in subsitemaps.

So apparently, the context for the redirector invoked from the 
flowscript after the continuation is resumed is the context that 
matched the continuation resource, *not* the context that originally 
invoked the flow.

You should have errors in your log files when getting this kind of 
InvalidContinuationException:

        if (!kont.interpreterMatches(interpreterId)) {
            getLogger().error(
                    "WK: Continuation (" + kont.getId()
                            + ") lookup for wrong interpreter. Bound 
to: "
                            + kont.getInterpreterId() + ", looked up 
for: "
                            + interpreterId);
            return null;
        }


You guys who know this stuff inside and out are probably saying, 
"well, of course!" :-)... but am I weird to find this 
counterintuitive?  WDYT?

I' have to put an appropriate comment in the docs about that.

Leszek could tell more about this, but there has been some recent 
modifications to forbid this: a continuation can only be called 
within the sitemap where it was created.

It is YOU that have to assure that the continuations gets resumed in 
the same context. As you see in the code pasted above current 
implementation of ContinuationsManager requests the flow interpreter 
to identify itself. Interpreter ID is being compared to the one stored 
in continuation - if it doesn't match you won't be able to resume it.

What you request is not a trivial change. Currently it is the 
interpreter that is resolved first (based on current sitemap context). 
Then it is interpreter's responsibility to lookup and resume a proper 
continuation. I do not know if it is possible to invert the behaviour:
- first the continuations gets looked up
- the sitemap context is changed based on the interpreter info stored 
in continuation (the id is not enough as it is a resource path that 
would have to get parsed every time)
- the flow interpreter bound to sitemap is being invoked with ready to 
go WebContinuation.

I don't think we should go that far: IMO, having an exception with a 
clear reason message is enough, as it shows that there is a bug in the 
application that needs to be fixed. Mark had no such exception, and 
that's why he spent much time to find the problem.

Sylvain
--
Sylvain Wallez                                  Anyware Technologies
http://www.apache.org/~sylvain           http://www.anyware-tech.com
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