[Interest] Binding based on typeof doesn't work any more

[mail at herrdiel.de]

Hi again,

I've found a better (JavaScript-) workaround without a dummy property:

@

text: { return ((Controller === "undefined" || !Controller) ? "" :
Controller.triedSteps) }

@

But still: Why has the behavior been (apparently) changed at all in the
first place? Or is it a bug after all?

BR
Sebastian

Am 17.10.2019 um 09:20 schrieb mail at herrdiel.de:
> Hi,
>
> I have a simple Label that has to show a property of a rootProperty, the latter not yet being created when the qml is loaded/created. Quite frequently I use this construct and it did work perfectly in older Qt versions (something before 12.1 - that's the earliest I have installed now):
> @
> //[main.qml, inside a Label]
> text: typeof Controller === "undefined" ? "" : Controller.successfulSteps
> @
> Now this doesn't show anything anymore. The following workaround does show the desired result:
> @
> property string dummy: ""
> text: dummy+(typeof Controller === "undefined" ? "" : Controller.successfulSteps)
> @
> This seems very hackish. Is there a better way to achieve this? Why has the behavior been (apparently) changed at all in the first place?
> The Controller has been set as a root property after loading the QML page:
> @
> //[main.cpp]
> QQmlApplicationEngine engine;
> engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
> Controller controller(&engine);
> engine.rootContext()->setContextProperty("Controller", QVariant::fromValue<Controller*>(&controller));
> @
>
> I've asked this in forum.qt.io before (https://forum.qt.io/topic/107828/binding-based-on-typeof-doesn-t-work-any-more)
>
> BR
> Sebastian
> -- 
> http://www.classintouch.de - Tablet-Software für Lehrer
>
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> Interest mailing list
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> https://lists.qt-project.org/listinfo/interest

-- 
http://www.classintouch.de - Tablet-Software für Lehrer

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