The onmessage Event in HTML DOM used when an object has received some message through an event source. The event object for onmessage Event supports the following schemes:
- data: It contains the actual message present inside it.
- origin: It contains the URL of the document that invoked the event.
- lastEventId: It works as descriptive attribute for the last message that was spotted in the message stream.
Note: Server-Sent Events are not supported in Internet Explorer.
Syntax:
object.onmessage = function(){myScript}; - Using the addEventListener() method
object.addEventListener("message", myScript);Example 1:
html
<!DOCTYPE html><html>
<head>
<title>
HTML DOM onmessage Event
</title>
</head>
<body>
<h1 id="gfg"></h1>
<div id="geeks"></div>
<!--Main Function-->
<script>
if (typeof(EventSource) !== "undefined") {
var source = new EventSource("/html/demo_sse.php");
source.onopen = function() {
document.getElementById("gfg").innerHTML =
"GeeksforGeeks";
};
source.onmessage = function(event) {
document.getElementById("geeks").innerHTML +=
event.data + "<br>";
};
}
else {
document.getElementById("geeks").innerHTML =
"browser does not support";
}
</script>
</body>
</html>
|
Output:
Example 2: Using the addEventListener() method
javascript
<!DOCTYPE html><html> <head> <title>
HTML DOM onmessage Event
</title>
</head> <body> <h1 id="gfg"></h1>
<div id="geeks"></div>
<!--main Function-->
<script>
if (typeof(EventSource) !== "undefined") {
var source = new EventSource("/html/demo_sse.php");
source.addEventListener("open", function() {
document.getElementById("gfg").innerHTML =
"GeeksforGeeks";
});
source.addEventListener("message", function(event) {
document.getElementById("geeks").innerHTML +=
event.data + "<br>";
});
} else {
document.getElementById("geeks").innerHTML =
"Your browser does not supported";
}
</script>
</body> </html> |
Output:
Supported browsers: The browser supported by onmessage Event are listed below:
- Google Chrome 60.0
- Edge 12.0
- Mozilla Firefox 9.0
- Internet Explorer 8.0
- Apple Safari 4.0
- Opera 47.0