[Laszlo-dev] Initialization difference between swf and dhtml

[Henry Minsky]

Note that implementing the lexical ordering is likely to break a
couple of legacy apps
that depend implicitly on the current ordering. Of course, several
DHTML versions are
already broken due to the different order now (I think I fudged a
couple of constraints in the amazon app to work around one case
already, with height initialization on a component) , so it's not
really a reason to try to preserve existing behavior.



On 11/28/06, Jim Grandy <jgrandy at openlaszlo.org> wrote:
>
> On Nov 28, 2006, at 2:33 PM, Adam Wolff wrote:
>
> > On Nov 28, Don Hopkins wrote:
> > [snip]
> >> I think it's pretty important to give class programmers the
> >> ability to
> >> control the order in which the attributes are initialized at class
> >> declaration time.  It's also sometimes useful for object users to
> >> control the initialization order at object instantiation time, but
> >> usually they shouldn't have to care, or be required to understand the
> >> inner workings.
> > Agree that this is appealing and sensible, but I don't think it's
> > practically possible. As a class user, I can say
> >
> >     <yourclass attr1="$once{ a }" attr2="$immediately{ b }"/>
> >
> > and then attr2 will be set before attr1 regardless of what you
> > might want
> > as the class implementor.
> >
> > A
>
> I think constraint satisfaction has to be a separate phase from
> attribute initialization, and really needs to have indeterminate
> execution order to preserve optimization/implementation flexibility.
> Attribute initialization to a constant value really needs lexical
> order, by class. The two shoud really be separate.
>
> jim
>
>


-- 
Henry Minsky
Software Architect
hminsky at laszlosystems.com