HTML 5 server sends events

HTML5 Server Send events (Server-sent event) allow Web pages to get updates from the server.

Browser support

All major browsers support server sending events, in addition to Internet Explorer.

Server-side Code instances

To make the above example work, you also need a server that can send data updates (such as PHP).

The syntax of the server-side event stream is very simple. Set the "Content-type" header to "Text/event-stream". Now, you can start sending an event stream

<? PHP Header (' Content-type:text/event-stream '); Header (' Cache-control:no-cache '); $time Date (' R '); Echo "Data:the server time is: {$time}\n\n"; Flush ();? >

Receive Server-sent event notifications

The EventSource object is used to send event notifications to the receiving server:

var source=New EventSource ("demo_sse.php"); source.onmessage=function( Event)  {  document.getElementById ("result"). Innerhtml+=event.data + "<br/>";  };

Detect Server-sent Event Support

In the tiy example above, we have written an extra piece of code to detect the browser support of the server sending the event:

if (typeof(EventSource)!== "undefined")  {  //  yes! Server-sent Events support!  // Some code ... ..   }Else  {  //  sorry! No server-sent Events Support:  }

Ext.: http://www.w3school.com.cn/html5/html_5_serversentevents.asp

HTML 5 server sends events