[Laszlo-dev] designing API which is LZX friendlyand Javascript-friendly

[Elliot Winard]

It sounds like this "script" way of instantiating objects would also provide a
way to re-parent objects.

I'm not too experienced regarding the internals of our LzView system's Flash
implementation.  Would it be very difficult to allow re-parenting?
-e

On Tue, 29 Nov 2005, Henry Minsky wrote:

> What I am beginning to think is that there need to be two different
> instantiation APIs
> for components, one which is designed to be called from LZX (XML), which
> does
> a lot of "automagic" setup, and one designed to be called from script, which
> exposes all
> the individual steps as much as possible. So you can decide for example to
> instantiate a
> menu item before there is a parent to add it to, or if you need to add it to
> a place in
> the parent which isn't at the end of the current list of items.
> 
> Tucker has proposed using something besides "new" to create new components
> in script. I think that is a good idea, but maybe we need to go one step
> further and have some conventions for two different standard ways to
> instantiate a component:
> 
> One way is the "LZX" way, where you pass a parent view, and an arglist, so
> that "new MyFrob(...)" behaves as much as possible like using <MyFrob> in
> LZX; as much magic as possible is done to install the object into it's
> parent environment.
> 
>  And the other would be the "script" way, which behaves in a more modular
> fashion, so you would expect to manually instantiate an
> object, then add it to a parent or not at your discretion, and set callbacks
> and event handlers, etc, manually.
> 
> 
> 
> On 11/29/05, Don Hopkins <dhopkins at donhopkins.com> wrote:
> >
> >  What are the advantages of dynamically creating user interface components
> > through xml data binding, instead of using a JavaScript api?
> >
> >
> >
> > I've been playing around with pie menus for Laszlo, trying to come up with
> > a Laszlish way to dynamically create and configure them.
> >
> >
> >
> > http://www.donhopkins.com/drupal/node/40
> >
> > http://www.donhopkins.com/lzxnet/my-apps/PieTest.lzx
> >
> > http://www.donhopkins.com/lzxnet/my-apps/PieTest.lzx?lzt=source
> >
> > http://www.donhopkins.com/lzxnet/my-apps/piemenu.lzx?lzt=source
> >
> >
> >
> > The Laszlo pie menus don't currently support an API for modifying the
> > menus dynamically, but I've been thinking about how that should work, and
> > how it could support user-editable menus that knew how to write themselves
> > back out as XML.
> >
> >
> >
> > Some pie menus are dynamically generated from data, so all items are
> > usually handled the same (or from a small set of pre-defined handlers based
> > on the dataset), but other pie menus are designed by hand with custom
> > handlers, tracking feedback and graphical resources associated with each
> > item.
> >
> >
> >
> > One problem with only defining widgets from XML, is how do you attach
> > custom methods and event handlers to widgets?
> >
> >
> >
> > Including custom JavaScript handlers and constraints in the widget xml
> > definition would require a JavaScript compiler in the Flash player (but it
> > would be possible in the DHTML version of Laszlo). You have to pre-define
> > all the handlers and constraint expressions as named functions, refer to
> > their names in the xml, and look them up at run-time.
> >
> >
> >
> >             -Don
> >
> >
> >
> >
> >
> 
> 
> 
> --
> Henry Minsky
> Software Architect
> hminsky at laszlosystems.com
>