Get Warning "qt.core.qobject.connect: QObject::connect: signal not found in NodeDelegateModel" while using load *.dll method.

[sirius-william]

I make a node plugin to extend my application. User can develop their own Node by inheriting 'NodeDelegateModel' class and compile it as SHARED library (*.dll). The application will load *.dll at the runtime and do the following code to connect signals: `std::unique_ptr<NodeDelegateModel> new_node = construct_func();

    id = newNodeId();

    connect(new_node.get(),
            &NodeDelegateModel::dataUpdated,
            [id, this](PortIndex const portIndex) {
                std::cout << "data_update" << std::endl;
                std::unordered_set<ConnectionId> const &connected = connections(id,
                                                                                PortType::Out,
                                                                                portIndex);
                QVariant const portDataToPropagate = portData(id, PortType::Out, portIndex, PortRole::Data);
                for (auto const &cn: connected) {
                    setPortData(cn.inNodeId, PortType::In, cn.inPortIndex, portDataToPropagate, PortRole::Data);
                }
            });
    connect(new_node.get(),
            &NodeDelegateModel::portsAboutToBeDeleted,
            this,
            [id, this](PortType const portType, PortIndex const first, PortIndex const last) {
                portsAboutToBeDeleted(id, portType, first, last);
            });

    connect(new_node.get(),
            &NodeDelegateModel::portsDeleted,
            this,
            &NodeGraphicsModel::portsDeleted);

    connect(new_node.get(),
            &NodeDelegateModel::portsAboutToBeInserted,
            this,
            [id, this](PortType const portType, PortIndex const first, PortIndex const last) {
                portsAboutToBeInserted(id, portType, first, last);
            });

    connect(new_node.get(),
            &NodeDelegateModel::portsInserted,
            this,
            &NodeGraphicsModel::portsInserted);`

*.dll can load correctly. But after calling 'addNode' or after doing others (maybe not after addNode), I got warning "qt.core.qobject.connect: QObject::connect: signal not found in NodeDelegateModel" 5 times. The node can add into Scene but can not put in right position. I think the signals above are not connected correctly. But why? What should I do while developing the the using loading *dll.

[sirius-william]

My *.dll project is compiled using following header file: `class Q_DECL_EXPORT NODE_EDITOR_PUBLIC ValueNode : public NodeDelegateModel {

Q_OBJECT

public:
    QString caption() const override;

    QString name() const override;

    unsigned int nPorts(QtNodes::PortType portType) const override;

    NodeDataType dataType(QtNodes::PortType portType, PortIndex portIndex) const override;

    void setInData(std::shared_ptr<NodeData> nodeData, PortIndex const portIndex) override;

    std::shared_ptr<NodeData> outData(const PortIndex port) override;

    QWidget *embeddedWidget() override;
    
private:
    QLineEdit *edit;
};`

[nolankramer]

Plugins (shared libraries), typically are developed with __declspec(dllimport) as the class attribute - as their headers are never compiled against, so it is assumed their symbols are always imported by the linking program.