Undefined properties and return types when using QWebChannel

Question

Based on QT QWebEnginePage::setWebChannel() transport object and Qt: Cannot invoke shared object methods/properties from javascript I tried to make a small demo to test the

Answer 1

Faced same issue... Reading doc's carefully gave me the answer. The answer is that communication between Qt and JS in Qt5 is asynchronous. You have to provide callback function which will be called after method completed and result value received.

Instead of calling

var n = theQtObj.getInt(X);
PrintLog("  back in js with n="+n);

you can call at as

theQtObj.getInt(X, function(n) {
    PrintLog(" back in js with n="+n);
});