[Laszlo-dev] For Review: Change 20071016-hqm-4 Summary: fix for DHTML replication bug

[André Bargull]

Changing the signature of "applyConstraint" must be well documented and 
you need to maintain backward-compatibility, because this is a public 
function, so other folks are using it, too!
[Just as a reminder concerning: "There's only a couple of callers to 
applyConstraint right now, ..."]


Henry Minsky wrote:
> That makes sense, to pass the object down instead of the dependencies 
> list.  There's only a couple of callers to applyConstraint right now, 
> but one of them is this one caller in LaszloView that makes it's own 
> dependencies list:
>
> function setPosConstraint ( v , f , widthorheight ){
>     var d = [ v , widthorheight  , this , widthorheight ];
>     this.applyConstraint( widthorheight == "width" ? "x" : "y" , f , d );
> }
>
>
> How do think I should handle that? I could make an object and put a 
> .dependencies on it and pass that I guess.
>
> On 10/16/07, *P T Withington * <ptw at pobox.com <mailto:ptw at pobox.com>> 
> wrote:
>
>     In fact, wouldn't it make more sense to move all the logic about
>     dependencies inside applyConstraint so it will be handled correctly
>     in one place and update all the callers?  I see no reason to have the
>     callers compute the dependencies out of line, you just need to pass
>     the target (this) down to applyConstraint.
>
>     On 2007-10-16, at 16:40 EDT, P T Withington wrote:
>
>     > Not approved.
>     >
>     > 1) This code should be modeled on the known-working code in LzNode:
>     >
>     >>         if (rp instanceof Function && ('dependencies' in rp)) {
>     >>             this.applyConstraint( p , rp , rp.dependencies.call
>     >> (this) );
>     >>         }
>     >
>     > rather than creating the mystery `_t` attribute.
>     >
>     > 2) There seems to be another branch of the code that replicates the
>     > same bug which should also be rewritten in modern style.
>     >
>     > 3) What about the case of a $once constraint?  Will it be handled
>     > correctly?  In LzNode when there are no dependencies, the
>     > constraint function is still called at least once.  I don't see in
>     > this code where that is handled.
>     >
>     > On 2007-10-16, at 15:24 EDT, Henry Minsky wrote:
>     >
>     >> Change 20071016-hqm-4 by hqm at IBM-2E06404CB67 on 2007-10-16
>     >> 15:19:46 EDT
>     >>     in /cygdrive/c/users/hqm/openlaszlo/trunk
>     >>     for http://svn.openlaszlo.org/openlaszlo/trunk
>     >>
>     >> Summary: fix for DHTML replication bug
>     >>
>     >> New Features:
>     >>
>     >> Bugs Fixed: LPP-4893
>     >>
>     >> Technical Reviewer: andre
>     >> QA Reviewer: ptw
>     >> Doc Reviewer:
>     >>
>     >> Documentation:
>     >>
>     >> check for null dependencies function before calling it
>     >>
>     >> Release Notes:
>     >>
>     >> Details:
>     >>
>     >>
>     >> Tests:
>     >>
>     >> test case from bug, smokecheck, amazon app
>     >>
>     >> Files:
>     >> M      WEB-INF/lps/lfc/data/LzReplicationManager.lzs
>     >>
>     >> Changeset: http://svn.openlaszlo.org/openlaszlo/patches/20071016-
>     >> hqm-4.tar
>     >>
>     >>
>     >> --
>     >> Henry Minsky
>     >> Software Architect
>     >> hminsky at laszlosystems.com <mailto:hminsky at laszlosystems.com>
>     >
>
>
>
>
> -- 
> Henry Minsky
> Software Architect
> hminsky at laszlosystems.com <mailto:hminsky at laszlosystems.com>
>