return python dict to QML (PySide2)

Question

I\'m trying to find a way to return a python dictionary from a PySide2.QtCore.Slot.

main.py

import sys
from PySide2.QtCore import         


        

Answer 1

The basic types of python when they are exported to QML are converted to their corresponding type since they are supported, but for a Slot() to return something the data type must be indicated through the result parameter, in this QVariant as a string.

Example:

main.py

from PySide2 import QtCore, QtGui, QtQml


class Helper(QtCore.QObject):
    @QtCore.Slot(result='QVariant')
    def foo(self):
        return {"a": 1, "b": 2}


if __name__ == '__main__':
    import sys

    app = QtGui.QGuiApplication(sys.argv)

    engine = QtQml.QQmlApplicationEngine()
    helper = Helper()
    engine.rootContext().setContextProperty("helper", helper)
    engine.load(QtCore.QUrl.fromLocalFile('main.qml'))
    if not engine.rootObjects():
        sys.exit(-1)
    sys.exit(app.exec_())

main.qml

import QtQuick 2.9
import QtQuick.Controls 2.4

ApplicationWindow {
    visible: true
    Component.onCompleted: { 
        var data = helper.foo()
        for(var key in data){
            var value = data[key]
            console.log(key, ": ", value)
        }
    }
}

Output:

qml: a :  1
qml: b :  2