[Seaside] Generated links (anchor -> callback)

[Dale Henrichs]

Julian,

I don't think this is related to fixBlockTemps - We're compliant with the ANSI spec except for this particular bug (and in 3.0 the bug will be fixed). 

The problem is that the block has 'lost' the value of the temp variable - the slot is shared across all block invocations, so I don't think there is a simple solution, other than a workaround similar to what James suggested.

Fixing this bug would involve some major surgery on the block implementation, so we've been reluctant to fix it in 2.x. 

Dale

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

| Hm.. this sounds exactly like the lack of full block closures in
| Squeak. I was unaware that Gemstone had a similar problem.
| 
| Could it not be fixed in Gemstone with an implementation of
| #fixCallbackTemps similar to the one in Squeak?
| 
| Julian
| 
| On Mon, Jul 6, 2009 at 3:44 AM, James Foster<Smalltalk at jgfoster.net>
| wrote:
| > Hi Mark,
| >
| > As Dale mentioned, GemStone doesn't quite handle the block the way
| you
| > expect. The workaround is to help the compiler see that this is
| really a new
| > context. I generally do this with a new method:
| >
| > renderContentOn: canvas
| >
| >        1 to: 10 do: [:index | self renderIndex: index on: canvas].
| > %
| > renderIndex: anInteger on: aCanvas
| >
| >        aCanvas anchor
| >                callback: [self value: anInteger];
| >                with: anInteger.
| >        aCanvas space.
| > %
| >
| > Because the refactoring tends to give smaller, better named methods,
| I
| > generally don't find this GemStone "bug" to be much of a burden.
| >
| > James
| >
| > On Jul 5, 2009, at 4:14 PM, Mark Ross wrote:
| >
| >> Hi seaside list!
| >>
| >> I'm roughly new in developing seaside. Trying out some seaside
| >> development.
| >>
| >> I'm using:
| >> GemStone/S 64 Bit
| >> 2.3.1 Build: gss64_2_3_x_branch-20643
| >> Thu Dec  4 11:33:32 2008
| >>
| >> with GemTools 2.3.1
| >>
| >> I would like create links on my page - with generated URLS, which
| have the
| >> value of the index from render time.
| >>
| >> I try by using something like this:
| >>
| >> initialize
| >>       super initialize.
| >>       self value: 0
| >>
| >> renderContentOn: canvas
| >>
| >> canvas text: self value.
| >>
| >>  1 to: 10 do: [ :index |
| >>      canvas anchor
| >>         callback:[ self value: index  ];
| >>                with: index.
| >>      html space ].
| >>
| >> -> The value is everytime clicking on a link '10' - which I would
| >> understand, if i didn't read the tutorial on the seaside.st site:
| >>
| >> -----snip -----
| >> renderContentOn: html
| >>  1 to: 10 do: [ :index |
| >>      html anchor
| >>         callback: [ index inspect ];
| >>         with: index.
| >>      html space ]
| >>
| >> It will generate a series of links, labelled from 1 to 10. Because
| the
| >> action blocks capture the current value of the i variable, each one
| will
| >> have a distinct callback: clicking on the "1" link will evaluate 1
| >> inspect, on the "2" link will evaluate 2 inspect, and so on. The
| block
| >> closure is being used to maintain all of the interesting state for
| the
| >> link.
| >> -----snap-----
| >>
| >> Please, can somebody help me out finding my mistake?
| >>
| >> Best regards
| >>
| >> Mark
| >>
| >>
| >> _______________________________________________
| >> seaside mailing list
| >> seaside at lists.squeakfoundation.org
| >> http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside
| >>
| >
| > _______________________________________________
| > seaside mailing list
| > seaside at lists.squeakfoundation.org
| > http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside
| >
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