javascript - Coldfusion Websockets "User is typing..."功能

Question

我正在使用 Coldfusion 10 的 websockets 并进行了简单的聊天以进行测试。我见过几个聊天，他们有“用户正在输入...”文本，当其他用户正在输入时显示。有谁知道如何有效地实现这一点？

Answer 1

再创建一个 channel “通知”，并在用户执行“keyDown”时发布“User is typing”，在“keyUp”时发布“emptystring”。

与您聊天时订阅此 channel 。接收方此 channel 的目标应是其内部 html 可以填充“用户正在键入”消息。

伪代码:

<cfwebsocket name="notificationSocket" 
             onmessage="notifyHandler"
             subscribeto="notificationChannel" >

<cfwebsocket name="ChatSocket" 
             onmessage="chatHandler"
             subscribeto="chatChannel" >

<!-- Conversation displayer -->
<div id="messageBoard"></div>

<!-- your text message input area -->
<textarea onKeyDown="sayTyping()" onKeyUp="sayStopped()" id="chatInput"></textarea>
<div id="notifyArea"></div>
<input name="submit" onClick="publishMessage()"></textarea>

<script>

    /*chat Functions*/
    var publishMessage = function(){
        var msg = document.getElementById('chatInput').value;
        mycfwebsocketobject.publish("chatChannel", msg );
    };

    var chatHandler = function(msgObj){
        document.getElementById('messageBoard').innerHTML += ColdFusion.JSON.encode(msgObj);
    };


    /*notifying Functions*/
    var notifyHandler = function(noteObj){
        document.getElementById('notifyArea').innerHTML = ColdFusion.JSON.encode(noteObj);
    };    

    var sayTyping = function(){
        mycfwebsocketobject.publish("notificationchannel","User is Typing..." );
    };
    var sayStopped = function(){
        mycfwebsocketobject.publish("notificationchannel","" );
    };

</script>

另一个改进是让一个 div 已经包含文本“用户正在输入”，并且您的 channel 将文本广播为“显示”和“不显示”。这基本上是给显示和隐藏它的类名。流量减少。

方法 2:使用相同的 channel

<cfwebsocket name="ChatSocket" 
             onmessage="chatHandler"
             subscribeto="chatChannel" >

<!-- Conversation displayer -->
<div id="messageBoard"></div>

<!-- your text message input area -->
<textarea onKeyDown="sayTyping()" onKeyUp="sayStopped()" id="chatInput"></textarea>
<div id="notifyArea" class="no">User is typing...</div>
<input name="submit" onClick="publishMessage()"></textarea>

<script>

    /*chat Functions*/
    var publishMessage = function(){
        var msg = document.getElementById('chatInput').value;
        mycfwebsocketobject.publish("chatChannel", msg );
    };

    var chatHandler = function(msgObj){
        var msg = ColdFusion.JSON.encode(msgObj);
        if (msg == '@userTyping@-yes'){
            notifyHandler('yes');
        }
        else if (msg == '@userTyping@-no'){
            notifyHandler('no');
        }
        else {
            document.getElementById('messageBoard').innerHTML += msg;
        }
    };


    /*notifying Functions*/
    var notifyHandler = function(action){

        document.getElementById('notifyArea').className = action;

        /*call the notify handler with off to stop showing the user is typing message
        after a certain interval of time. This is to avoid someone believing that 
        partner is still typing even when the connection is lost*/

        if(action == 'on'){
            setTimeout(function(){notifyHandler('no')},250);
        }
    };    

    var sayTyping = function(){
        mycfwebsocketobject.publish("chatChannel","@userTyping@-yes" );
    };
    var sayStopped = function(){
        mycfwebsocketobject.publish("chatChannel","@userTyping@-no" );
    };

</script>
<style>
.yes { display:block;}
.no { display:none;}
</style>

人们总是可以通过将消息键入“@userTyping@-yes”或“@userTyping@-no”来欺骗此代码。但正如我所说，这只是一个 POC。此外，对于您提到的超时，keyUp 无论如何都会处理它。但您也可以通过 setTimeout() 调用 notifyHandler()，如上所示。