Qt 5.9 | Qt WebChannel | Qt WebChannel ChatClient QML Example | qmlchatclient.qml Example File

Qt 5.9.4 Reference Documentation

# qmlchatclient.qml Example File

chatclient-qml/qmlchatclient.qml

      /****************************************************************************
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      ** Copyright (C) 2017 The Qt Company Ltd.
      ** Copyright (C) 2016 basysKom GmbH, author Bernd Lamecker <bernd.lamecker@basyskom.com>
      ** Contact: https://www.qt.io/licensing/
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      ** This file is part of the QtWebChannel module of the Qt Toolkit.
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      import QtQuick 2.2
      import QtQuick.Dialogs 1.2
      import QtQuick.Controls 2.0
      import QtQuick.Window 2.0
      import QtQuick.Layouts 1.1
      import Qt.WebSockets 1.0
      import "qwebchannel.js" as WebChannel

      ApplicationWindow {
          id: root

          property var channel
          property string loginName: loginUi.userName.text

          title: "Chat client"
          width: 640
          height: 480
          visible: true

          WebSocket {
              id: socket

              // the following three properties/functions are required to align the QML WebSocket API
              // with the HTML5 WebSocket API.
              property var send: function(arg) {
                  sendTextMessage(arg);
              }

              onTextMessageReceived: {
                  onmessage({data: message});
              }

              property var onmessage

              active: true
              url: "ws://localhost:12345"

              onStatusChanged: {
                  switch (socket.status) {
                  case WebSocket.Error:
                      errorDialog.text = "Error: " + socket.errorString;
                      errorDialog.visible = true;
                      break;
                  case WebSocket.Closed:
                      errorDialog.text = "Error: Socket at " + url + " closed.";
                      errorDialog.visible = true;
                      break;
                  case WebSocket.Open:
                      //open the webchannel with the socket as transport
                      new WebChannel.QWebChannel(socket, function(ch) {
                          root.channel = ch;

                          //connect to the changed signal of the userList property
                          ch.objects.chatserver.userListChanged.connect(function(args) {
                              mainUi.userlist.text = '';
                              ch.objects.chatserver.userList.forEach(function(user) {
                                  mainUi.userlist.text += user + '\n';
                              });
                          });

                          //connect to the newMessage signal
                          ch.objects.chatserver.newMessage.connect(function(time, user, message) {
                              var line = "[" + time + "] " + user + ": " + message + '\n';
                              mainUi.chat.text = mainUi.chat.text + line;
                          });

                          //connect to the keep alive signal
                          ch.objects.chatserver.keepAlive.connect(function(args) {
                              if (loginName !== '')
                                  //and call the keep alive response method as an answer
                                  ch.objects.chatserver.keepAliveResponse(loginName);
                          });
                      });

                      loginWindow.show();
                      break;
                  }
              }
          }

          MainForm {
              id: mainUi
              anchors.fill: parent

              Connections {
                  target: mainUi.message
                  onEditingFinished: {
                      if (mainUi.message.text.length) {
                          //call the sendMessage method to send the message
                          root.channel.objects.chatserver.sendMessage(loginName,
                                                                      mainUi.message.text);
                      }
                      mainUi.message.text = '';
                  }
              }
          }

          Window {
              id: loginWindow

              title: "Login"
              modality: Qt.ApplicationModal
              width: 300
              height: 200

              LoginForm {
                  id: loginUi
                  anchors.fill: parent

                  nameInUseError.visible: false

                  Connections {
                      target: loginUi.loginButton

                      onClicked: {
                          //call the login method
                          root.channel.objects.chatserver.login(loginName, function(arg) {
                              //check the return value for success
                              if (arg === true) {
                                  loginUi.nameInUseError.visible = false;
                                  loginWindow.close();
                              } else {
                                  loginUi.nameInUseError.visible = true;
                              }
                          });
                      }
                  }
              }
          }

          MessageDialog {
              id: errorDialog

              icon: StandardIcon.Critical
              standardButtons: StandardButton.Close
              title: "Chat client"

              onAccepted: {
                  Qt.quit();
              }
              onRejected: {
                  Qt.quit();
              }
          }
      }