Hi,
Ok, let me clarify: When the JavaScript engine wants to map a JS null value to a QVariant, it used to use QVariant(QMetaType::VoidStar, (void *)0); and now uses QVariant::fromValue(nullptr); If a string is to be converted to a QVariant, it will naturally use QVariant(thatString). I think if that string happens to be a null QString, then QVariant isNull() will return true, right? If that is unsufficient for the pim code here (or generally any other code), then my recommendation would be to change the signature to take a QJSValue instead of a QVariant. The engine supports that transparently and the QJSValue API allows distinguishing between a JavaScript null and a string, etc. So that is another option. Simon ________________________________ From: Development <development-bounces+simon.hausmann=qt...@qt-project.org> on behalf of Thiago Macieira <thiago.macie...@intel.com> Sent: Tuesday, September 27, 2016 11:59:50 PM To: development@qt-project.org Subject: Re: [Development] Behaviour change in QML in Qt 5.8 regarding null On terça-feira, 27 de setembro de 2016 18:22:34 PDT Simon Hausmann wrote: > I'm fairly sure we used QVariant(QMetaType::VoidStar); Can you guarantee that the only time the QML engine generates null QVariants is for null JS Values? That is, no null QStrings, null QVariantLists, null QVariantMaps/Hahes, null doubles, etc.? If that's the case, I'd recommend a doc update and unit tests. Chris can fix his code for isNull(). Note: QVariant::fromValue(nullptr).isNull() == false QVariant(QMetaType::Nullptr).isNull() == true -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel Open Source Technology Center _______________________________________________ Development mailing list Development@qt-project.org http://lists.qt-project.org/mailman/listinfo/development Development Info Page - Qt<http://lists.qt-project.org/mailman/listinfo/development> lists.qt-project.org To see the collection of prior postings to the list, visit the Development Archives. Using Development: To post a message to all the list members ...
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