Python QWebEngineView and QWebChannel

TRIAEIOU

Hi, I can't get a minimal implementation of QWebChannel communication between a python script and QWebEngineView to work, what am I missing here?

import sys
from PySide6.QtCore import QObject
from PySide6.QtWebChannel import QWebChannel
from PySide6.QtWebEngineWidgets import QWebEngineView
from PySide6.QtWidgets import QApplication

class Py(QObject):
    def msg(self, msg):
        print("msg: ", msg)

if __name__ == "__main__":
    app = QApplication(sys.argv)
    web = QWebEngineView()
    channel = QWebChannel(web)
    py = Py(app)
    channel.registerObject("py", py)
    web.page().setWebChannel(channel)
    web.setHtml('''
    <html>
        <head>
            <script type="text/javascript" src="qrc:///qtwebchannel/qwebchannel.js"></script>
            <script>
                var py
                channel = new QWebChannel(qt.webChannelTransport, function(channel) {
                    py = channel.objects.py
                })
            </script>
        </head>
        <body>
            Demo<br>
            <button onclick="py.msg('button clicked')">click me</button>
        </body>
    </html>
    ''')
    web.show()
    app.exec()

Thanks!

TRIAEIOU

@TRIAEIOU
Solved, I was missing @Slot:

import sys, json
from PySide6.QtCore import QObject, Slot
from PySide6.QtWebChannel import QWebChannel
from PySide6.QtWebEngineWidgets import QWebEngineView
from PySide6.QtWidgets import QApplication

class Py(QObject):
    @Slot(str, result=str)
    def msg(self, msg):
        print("py.msg: ", msg)
        return json.dumps("clicked")

if __name__ == "__main__":
    app = QApplication(sys.argv)
    web = QWebEngineView()
    channel = QWebChannel(web)
    py = Py(app)
    channel.registerObject("py", py)
    web.page().setWebChannel(channel)
    web.setHtml('''
        <html>
            <head>
                <script type="text/javascript" src="qrc:///qtwebchannel/qwebchannel.js"></script>
                <script type="text/javascript">
                    var pymsg
                    new QWebChannel(qt.webChannelTransport, function(channel) {
                        pymsg = function (msg, cb = Function.prototype) {
                            channel.objects.py.msg(msg, (res) => cb(JSON.parse(res)))
                            return false
                        }
                    })
                </script>
            </head>
            <body>
                <button onclick="pymsg('button clicked', (res) => {alert(res)})">click me</button>
            </body>
        </html>
    ''')
    web.show()
    app.exec()