Qt WebChannel

Qt WebChannel enables peer-to-peer communication between a server (QML/C++ application) and a client (HTML/JavaScript or QML application). It is supported out of the box by Qt WebEngine. In addition, it can work on all browsers that support WebSockets, enabling Qt WebChannel clients to run in any JavaScript environment (including QML). This requires implementing a custom transport based on Qt WebSockets.

The module provides a JavaScript library for seamless integration of C++ and QML applications with HTML/JavaScript and QML clients. The clients must use the JavaScript library to access the serialized QObjects published by the host applications.

Using the Module

QML API

The QML types of the module are available through the QtWebChannel import. To use the types, add the following import statement to your .qml file:

import QtWebChannel

C++ API

Using a Qt module requires linking against the module library, either directly or through other dependencies. Several build tools have dedicated support for this, including CMake and qmake.

Building with CMake

Use the find_package() command to locate the needed module component in the Qt6 package:

find_package(Qt6 REQUIRED COMPONENTS WebChannel)
target_link_libraries(mytarget PRIVATE Qt6::WebChannel)

For more details, see the Build with CMake overview.

Building with qmake

To configure the module for building with qmake, add the module as a value of the QT variable in the project's .pro file:

QT += webchannel

Examples

Reference

Licenses

Qt WebChannel is available under commercial licenses from The Qt Company. In addition, it is available under free software licenses. These free software licenses are GNU Lesser General Public License, version 3, or the GNU General Public License, version 2. See Qt Licensing for further details.

© 2023 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.