Qt Documentation

echoclient.html Example File

echoserver/echoclient.html 
<html>
    <head>
        <title>WebSocket Echo Client</title>
    </head>
    <body>
        <h1>WebSocket Echo Client</h1>
        <p>
            <button onClick="initWebSocket();">Connect</button>
            <button onClick="stopWebSocket();">Disconnect</button>
            <button onClick="checkSocket();">State</button>
        </p>
        <p>
            <textarea id="debugTextArea" style="width:400px;height:200px;"></textarea>
        </p>
        <p>
            <input type="text" id="inputText" onkeydown="if(event.keyCode==13)sendMessage();"/>
            <button onClick="sendMessage();">Send</button>
        </p>

        <script type="text/javascript">
            var debugTextArea = document.getElementById("debugTextArea");
            function debug(message) {
                debugTextArea.value += message + "\n";
                debugTextArea.scrollTop = debugTextArea.scrollHeight;
            }

            function sendMessage() {
                var msg = document.getElementById("inputText").value;
                if ( websocket != null )
                {
                    document.getElementById("inputText").value = "";
                    websocket.send( msg );
                    console.log( "string sent :", '"'+msg+'"' );
                }
            }

            var wsUri = "ws://localhost:1234";
            var websocket = null;

            function initWebSocket() {
                try {
                    if (typeof MozWebSocket == 'function')
                        WebSocket = MozWebSocket;
                    if ( websocket && websocket.readyState == 1 )
                        websocket.close();
                    websocket = new WebSocket( wsUri );
                    websocket.onopen = function (evt) {
                        debug("CONNECTED");
                    };
                    websocket.onclose = function (evt) {
                        debug("DISCONNECTED");
                    };
                    websocket.onmessage = function (evt) {
                        console.log( "Message received :", evt.data );
                        debug( evt.data );
                    };
                    websocket.onerror = function (evt) {
                        debug('ERROR: ' + evt.data);
                    };
                } catch (exception) {
                    debug('ERROR: ' + exception);
                }
            }

            function stopWebSocket() {
                if (websocket)
                    websocket.close();
            }

            function checkSocket() {
                if (websocket != null) {
                    var stateStr;
                    switch (websocket.readyState) {
                        case 0: {
                            stateStr = "CONNECTING";
                            break;
                        }
                        case 1: {
                            stateStr = "OPEN";
                            break;
                        }
                        case 2: {
                            stateStr = "CLOSING";
                            break;
                        }
                        case 3: {
                            stateStr = "CLOSED";
                            break;
                        }
                        default: {
                            stateStr = "UNKNOW";
                            break;
                        }
                    }
                    debug("WebSocket state = " + websocket.readyState + " ( " + stateStr + " )");
                } else {
                    debug("WebSocket is null");
                }
            }
        </script>
    </body>
</html>

© 2018 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.