Function binding for QML

qml-function-binding.cpp

// Basic idea is to export the function as a Qt property that holds a JavaScript callable
Q_PROPERTY(QJSValue hasRoles READ hasRolesFunction NOTIFY rolesChanged FINAL)

// Possible implementation of such property
QJSValue ProfileService::hasRolesFunction()
{
    // create function factory to bind `this`
    auto factory = qmlEngine(this)->evaluate("profileService => (roles => (profileService.roles & roles) === roles)"_l1);

    if (factory.isError()) {
        qCCritical(lcProfile, "Could not create hasRoles() factory: %ls", qUtf16Printable(factory.toString()));
        return {};
    }

    // create actual function bound to `this`
    auto function = factory.call({qml->newQObject(this)});

    if (function.isError()) {
        qCCritical(lcProfile, "Could not create hasRoles() function: %ls", qUtf16Printable(function.toString()));
        return {};
    }

    return function;
}