How can I call a pointer of an QObject in a QML File?

Question

I'm developping an application for Blackberry 10 and I'm using the Momentics IDE (BB native SDK).

I get the following error when I try to execute the code below. Any one have an idea how can I fix this ?

Error

QMetaProperty::read: Unable to handle unregistered datatype 'DataHandler*' for property 'xxx::dataHandler' asset:///main.qml:104: TypeError: Result of expression 'xxx.dataHandler' [undefined] is not an object. Process 627863799 (xxx) terminated SIGSEGV code=1 fltno=11 ip=08055b30(/accounts/1000/appdata/com.ddd.xxx.testDev_e_xxx45b0f435/app/native/xxx@main+0x5d63) ref=006e0075

** xxx.hpp **

class xxx: public QObject { Q_OBJECT Q_PROPERTY(DataHandler* dataHandler READ getDataHandler) public: xxx(bb::cascades::Application *app); virtual ~xxx() { } Q_INVOKABLE DataHandler* getDataHandler() const; private: DataHandler* m_dataHandler; }

** xxx.cpp **

xxx::xxx(bb::cascades::Application *app) : QObject(app) { m_dataHandler = new DataHandler(); }

** QML file **

Button { id: backBtn objectName: "backBtnObject" text: qsTr("Back") + Retranslate.onLocaleOrLanguageChanged preferredWidth: backBtn.text.length visible: false onClicked: { xxx.dataHandler.displayLicencesList(); } }

Aralox · Accepted Answer · 2014-08-25 03:53:56Z

5

You need to register your pointer type like this

qRegisterMetaType<ClassA*>("ClassA*");

(source)

answered Aug 25, 2014 at 3:53

Aralox

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Comments

Valentin H · Accepted Answer · 2013-12-02 13:45:40Z

2

DataHandler is unknown type.

Q_PROPERTY docu says:

The type can be any type supported by QVariant

I'd try to encapsulate your DataHandler* in QVariant and make the property of type QVariant.

You could create the value containing your DataHandler pointer e.g like this:

const int DATA_HANDLER = QVariant::UserType +1; //... QVariant dataHandler( DATA_HANDLER, myDataHandlerPointer );

edited Dec 2, 2013 at 13:45

answered Dec 2, 2013 at 13:38

Valentin H

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2 Comments

Mohamed Jihed Jaouadi Over a year ago

Thx !! DataHandler is QObject class that I created for loading data stuffs. I don't know why it doesn't work? If you check this link, you will see that's possible to call pointer in the Q_Property.

Valentin H Over a year ago

@user2072762: OK, interesting. This docu link says, QObject-derived classes may be used as types if they were registered. Have you seen the chapter Registering C++ types with the QML type system? Maybe qmlRegisterType() could help?

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