Qt WebChannel ChatServer Example#
A simple chat server implemented using the QWebChannel
C++ API.
ChatServer provides a chat service that the Qt WebChannel ChatClient QML Application and Qt WebChannel ChatClient HTML Example can connect to.
Running the Example#
To run the example from Qt Creator, open the Welcome mode and select the example from Examples. For more information, visit Building and Running an Example.
Implementing a Chat Server#
The C++ application implements a QObject which provides all mechanisms required for a chat service. This object is published through a QWebChannel
which uses a WebSocket as transport.
The server provides a basic login
method (username only, no passwords), which must be successfully invoked before a client is able to chat. After login, a client can invoke the method sendMessage
and receive the signal newMessage
to write and receive messages. Furthermore, there is a userList
property which provides the names of all other connected clients. Additionally the server sends a keepAlive
signal periodically to all clients. The clients have to respond to this signal, otherwise the client will be removed from the userList
property.
The example shows how basic QObject elements can be used with QWebChannel
, that is signals (newMessage
), slots (sendMessage
), and properties (userList
).
Because this is a plain server application, separate clients are needed to interact with it. Qt WebChannel ChatClient QML Application and Qt WebChannel ChatClient HTML Example are client implementations compatible with this server.