error: variable 'QQmlComponent component' has initializer but incomplete type in Qt5

Question

i am playing with Exposing Attributes of C++ Types to QML in Qt5 based on this tutor http://qt-project.org/doc/qt-5.0/qtqml/qtqml-cppintegration-exposecppattributes.html. when i

Answer 1

You are not including QQmlComponent header in your main.cpp:

#include 

You are also trying to emit a signal that you haven't declared yet. You should declare it in your message.h like this:

signals:
    void authorChanged();

Check this example.