Hi,
Hope you are all having fun reading existing QML ;-) What I am finding
is creating QML is an exceeding simple task compared to reading
other's QML. The main culprit that inhibits my reading is the
'Component instance hierarchy' feature in
http://doc.qt.nokia.com/4.7-snapshot/qdeclarativescope.html. The code
which I am reading accesses components and ids all over the place. For
example, if we had a Component heirarchy A that contains B that inturn
contains C - C would access ids of A. B would set state (yes, _state_)
of something in A. C would react on states of A etc. When used this
way, ids have to be 'unique' and I think this pattern in most cases
results in unreadable code (as shown in the example in the
documentation too).
Authors seems to think of all these ids as a global pool of objects
that can be accessed from anywhere and think that this is declarative
programming e.g. C.state = A.something. Yes, it's declarative but it
should be done the other way around, in A's code, no?
So, am I correct in thinking that in general, a component should
_never_ really access anything else other than ids of it's own
regardless of how un-reusable and specialized it is? Each qml
component as much as possible should expose stuff as properties and
bindings should be done in the _parent_ component. I do understand
that there are cases that require child components to access parent
stuff.
So, is it a sane suggestion/feature request to add a 'pragma
strictScope' which I can add to the top of a QML file to disable this
feature? It would make reading QML infinitely good for me. Reminds me
of VB - the first thing in do is add 'Option Explicit' :-) I would do
the same in qml. Let me know if I am thinking very 'imperatively' :-)
On the topic of pragmas, I would also like to have a 'pragma
noSyntacticSugar'. QML has shortcuts which make it very hard for
beginners to understand why things don't work in QML. For example,
ListView {
delegate: Text { text: model.text }
}
versus
Text { id: textDelegate; text: model.text }
ListView {
delegate: textDelegate;
}
Oops, latter doesn't work. So, it would be nice to force people to
write Component { } so they _understand_ what's happening. Same goes
for default properties (I am looking the 'children' property).
Girish
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