Qt WebChannel Standalone Example

Standalone demonstrates how to use the QWebChannel C++ API to communicate with an external client. It is a simple chat between a C++ application and a remote HTML client running in your default browser.

Running the Example

You can run the example from:

• Qt Creator

  Open the Welcome mode and select the example from Examples. For more information, see Qt Creator: Tutorial: Build and run.

• Qt Extension for Visual Studio Code

  Run the Qt: Open Qt examples command from the Command Palette, and select the example from the list. For more information, see Qt Extension for Visual Studio Code: Tutorial: Build and run.

Communicating with a Remote Client

The C++ application sets up a QWebChannel instance and publishes a Core object over it. For the remote client side, the index.html file is opened. Both show a dialog with the list of received messages and an input box to send messages to the other end.

The Core emits the Core::sendText() signal when the user sends a message. The signal automatically gets propagated to the HTML client. When the user enters a message on the HTML side, Core::receiveText() is called.

All communication between the HTML client and the C++ server is done over a WebSocket. The C++ side instantiates a QWebSocketServer and wraps incoming QWebSocket connections in QWebChannelAbstractTransport objects. These objects are then connected to the QWebChannel instance.

Example project @ code.qt.io