Mark Lundquist wrote:
Hi Sylvain, thx for your reply...
....
However...
I realized that I have a nomenclature clash with my choice of
the name "model". I've been using the v2 API for a long time,
so I forgot in v1, there is a Form.model property that
denotes
the widget value tree.
The "model" property is only available on the toplevel form JS
object, so there may not be a clash.
It's not a hard "name clash", but it is a nomenclature clash in that
it's a different sense of the term "model". My new row "model"
property is truly the "model", as in "MVC" or as in
"loadFormFromModel()". The v1 "model" is "model" in terms of
"formmodel", I guess. I just think it's too confusing to have both
senses. I actually sort of wish the v1 "model" were called something
else, because it isn't the model /a la/ MVC.
You're right. The "form.model" is actually the value tree.
Maybe form.model should be renamed to "form.value"! Then you would
have these two expressions that mean the same thing (just as they look
like they should! :-):
form.value.foobar
and
form.lookupWidget('foobar').value
, right? :-)
Yes, and also "form.value.foo.bar.baz" and
"form.lookupWidget('foo/bar/baz').value". Naming it "form.values"
(plural) sounds better.
But for now in my working version of the code I settled on "rowModel"
to expose the row model object in Flowscript and JXT.
Now then, the following exchange has me totally confused:
It doesn't seem good to me to provide at the API level a way to
link the form to the data model,
No, no, it /is/ good... :-)
[ ...my rambling snipped...]
However, there are some uses cases where this makes sense. You can
then use widget attributes (see get/setAttribute) to attach some
application data of your liking to any widget, including repeater
rows.
See, that's the problem, this is what I have to deal with currently
:-)... I have two parallel structures: a Collection, and a Repeater.
If the Repeater does not give me a "view" to its collection, then I
have to do some kind of iteration to create associations somewhere
between the repeater rows and the collection elements, and this just
feels silly and wasteful. I've done it this way, decorating the
repeater rows with handles to the model data, and I just think that
since the binding layer is already iterating across the collection,
it should do this decoration for me! :-).
Yes. That's the idea behind the "bound repeater binding" idea
Reinhard pointed to.
Right. Which was your idea, and which I think I have gone and
implemented before I knew that somebody else had thought of it :-)...
Or have I not? Maybe I am misunderstanding Reinhard's reference and
it isn't really the same thing... or maybe you are misunderstanding
me, and thinking it's not the same thing, but it really _is_? :-)
Are you saying, "Ah yes, you're right... I thought of this before, and
now I remember why it _is_ a good idea (+1! :-)" ?
Or — are you saying "Ah, it looks like I did think of this too once,
but now on second thought I'm not so sure it was a good idea" ?
LOL! I of course remember this was my idea, and I still think it is good.
What doesn't seem good however, is to provide a way to link the data
model and the form, _without going through the binding_. It is ok for
some bindings to use widgets attributes are storage areas for their
stuff, but it isn't ok IMO for the _widget_ API to know about
application data.
I could live with there being a "callback" facility in the repeater
binding language, e.g. <fb:javascript> within <fb:on-bind>... know
what I mean? But that's sort of beyond my ability to implement, and
I was looking for something that I could actually do :-)
Extending the repeater binding to keep the connection to the data
model may be easier, no?
Well, it certainly was awfully easy :-) Tell you what, the change is
so ridiculously small, I'll just attach the diffs (they are against
src/blocks/forms/java/org/apache/cocoon/forms) and you can see if
we're talking about the same thing. At first this amounted to about 6
lines of code added, before I added the convenience flowscript
function (that I had mentioned in the original post that I wanted to
add... this doubled :-) the size of the mod). BTW, this function —
'getRowModel()' — I only added it in v2 ('cuz that's what I'm using!
:-). When I looked at v1's ScriptableWidget, I hesitated when I saw
that there are so few javascript functions defined there, and I wasn't
sure if this is really the right idiom for v1... Care to comment?
Well, this is exactly what I consider as wrong above :-)
That's the binding job to possibly use widget attributes to store data
that helps later on the form's save. But the form itself shouldn't have
to care about it.
So the changes should be in RepeaterBinding, and not in Repeater itself.
Sylvain
--
Sylvain Wallez Anyware Technologies
http://apache.org/~sylvain http://anyware-tech.com
Apache Software Foundation Member Research & Technology Director
