Description
Lets you create the WebSocket object in your CFM template. The tag creates a reference to the WebSocket JavaScript object at the client-side
Category
History
ColdFusion 11: Added a new attribute, secure. Also, in ColdFusion 11 Standard, there is no limit on the number of websockets that you can create.
ColdFusion 10: Added this tag.
Syntax
name="websocketName" onMessage="JavaScript function name" onOpen="JavaScript function name" onClose="JavaScript function name" onError="JavaScript function name" useCfAuth=true|false subscribeTo="channel_list" secure="true|false">
Attribute
Attribute |
Req/Opt |
Descriptions |
|---|---|---|
name |
Required |
The name of the WebSocket object. This is the reference to the JavaScript objects that are used to call WebSocket JavaScript functions. |
onMessage |
Required |
The JavaScript function that is called when the WebSocket receives a message from the server. It supports the argument, aEvent. This argument is the websocket event that is dispatched from the server. |
onOpen |
Optional |
The JavaScript function that is called when the WebSocket establishes a connection. |
onClose |
Optional |
The JavaScript function that is called when the WebSocket closes a connection. |
onError |
Optional |
The JavaScript function that is called if there is an error while performing an action over the WebSocket connection. |
usecfAuth |
Optional |
If set to true (default), users need not authenticate for WebSocket connection (provided they have already logged in to the application). This is the default value. |
subscribeTo |
Optional |
Comma-separated list of channels to subscribe to. You can specify any or all channels set in the Application.cfc. |
| secure | Optional | If true, the web socket communication will happen over SSL. |
Example
In the following example,
- The user is automatically subscribed to the stocks channel.
- You have specified the channel name in the Application.cfc.
- The example uses the default channel listener.
In the Index.cfm, you specify the channels to which the user can automatically subscribe to (using the attribute subscribeTo) and also define the message handler.
Application.cfc
{
this.name="websocketsampleapp1";
this.wschannels=[{name="stocks"}];
}
Index.cfm
<script type="text/javascript">
function mymessagehandler(aevent, atoken)
{
var message = ColdFusion.JSON.encode(atoken);
var txt=document.getElementById("myDiv");
txt.innerHTML +=message +"<br>";
}
</script>
<cfwebsocket name="mycfwebsocketobject" onmessage="mymessagehandler" subscribeto="stocks" >
<cfdiv id="myDiv"></cfdiv>
The code creates a JavaScript WebSocket object named mycfwebsocketobject. If the server sends a message, it calls mymessagehandler function.Since you have specified subscribeTo in the cfwebsocket tag, the WebSocket object automatically subscribes you to the channel stocks.
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