On Tue, Apr 29, 2014 at 11:32 PM, Rutledge Shawn
<[email protected]> wrote:
>
> On 29 Apr 2014, at 7:51 PM, Alan Alpert wrote:
>
>>> (3) Document that accessing ids from other .qml files without any interface
>>> (just relying on the fact that they are in the context) creates hard to
>>> maintain QML code.
>>
>> Agreed (honestly, it should already be there, I guess
>> https://bugreports.qt-project.org/browse/QTBUG-20453 was never
>> finished...).
>>
>> Again, we have some rough plans for a ".pragma strict". Which should ban
>> this.
>
> What exactly do you want to ban and what are the best alternatives? "Without
> any interface" implies there is a right way to share.
Correct answer: Define an interface. Probably best explained via the
attached examples: "Bad" has no interface defined for the object
reference, "Good" does.
Runner up: Singletons. When you can't or don't want to pass references
to individual object instances, you can pass it to a shared interface
instance and use that. Which is QML singletons, and is fairly
convenient already (though there are known issues like QTBUG-34418
which can make it less convenient than it should).
Workaround: Shared JS file. Does most of the same stuff as the
singleton (biggest exception: QTBUG-21844 ), and is available in
earlier versions. Should singletons be available, use them instead as
they have the declarative and typed interface benefits.
> In practice I'm often not sure about the scoping rules, so when something
> that I think should be accessible is not, I'm often not sure if that is a bug
> but just start looking for another way to do it (which sometimes can be
> clumsy).
If an id is not in file scope, then it's either a bug or an ugly
hidden feature that we keep around for convenience but you aren't
supposed to use ;) .
--
Alan Alpert
import QtQuick 2.1
MouseArea {
onClicked: anItem.color = "blue"
}
import QtQuick 2.1
MouseArea {
property Rectangle target
onClicked: target.color = "blue"
}
import QtQuick 2.1
Rectangle {
id: anItem
color: "red"
width: 200
height: 200
BadUser {
anchors.fill: parent
}
}
import QtQuick 2.1
Rectangle {
id: anItem
color: "red"
width: 200
height: 200
GoodUser {
target: anItem
anchors.fill: parent
}
}
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