QML Reloading in PyQt5

README.md

Usage

git clone https://gist.github.com/fa01c80080363df3433d.git qmlreload
cd qmlreload
python main.py

Edit either SceneGraphEditor.qml or Viewport.qml and then hover it and hit F5 to reload.

main.py

# Based on this question on StackOverflow
# http://stackoverflow.com/questions/19604552/qml-loader-not-shows-changes-on-qml-file

import sys
from PyQt5 import QtQml, QtGui, QtCore


class ComponentCacheManager(QtCore.QObject):
    def __init__(self, engine):
        super(ComponentCacheManager, self).__init__()
        self.engine = engine

    @QtCore.pyqtSlot()
    def trim(self):
        self.engine.clearComponentCache()


if __name__ == '__main__':
    app = QtGui.QGuiApplication(sys.argv)

    engine = QtQml.QQmlApplicationEngine()

    manager = ComponentCacheManager(engine)
    context = engine.rootContext()
    context.setContextProperty("componentCache", manager)

    engine.load(QtCore.QUrl.fromLocalFile("main.qml"))

    app.exec_()

main.qml

import QtQuick 2.5
import QtQuick.Controls 1.2
import QtQuick.Layouts 1.1
import QtQuick.Window 2.2

ApplicationWindow {
    id: window
    width: 300
    height: 200
    visible: true
    title: "Feather 0.1"

    Row {
        id: sv
        anchors.fill: parent

        Loader {
            property string path: "SceneGraphEditor.qml"

            width: 150
            height: 200
            source: path
        }

        Loader {
            property string path: "Viewport.qml"

            width: 150
            height: 200
            source: path
        }
    }

    MouseArea {
        id: ma
        anchors.fill: parent
        hoverEnabled: true
    }

    Action {
        shortcut: "F5"
        onTriggered: {
            var loader = sv.childAt(ma.mouseX, ma.mouseY);

            print("Reloading ", loader.path);

            loader.setSource("");
            componentCache.trim();
            loader.setSource(loader.path);
        }
    }
}

SceneGraphEditor.qml

import QtQuick 2.5

Rectangle {
	color: "purple"
}

Viewport.qml

import QtQuick 2.5

Rectangle {
	color: "yellow"
}

Thanks!!