onmessage Event
Example
Create a new EventSource object, and specify the URL of the page sending the
updates.
Each time an update is received, the onmessage event occurs. When an
onmessage event occurs, put the received data into the <div> element with id="myDIV":
var source = new EventSource("demo_sse.php");
source.onmessage = function(event) {
document.getElementById("myDIV").innerHTML += event.data + "<br>";
};
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More "Try it Yourself" examples below.
Definition and Usage
The onmessage event occurs when a message is received through an event source.
The event object for the onmessage event supports the following properties:
- data - Contains the actual message
- origin - The URL of the document that invoked the event
- lastEventId - the identifier of the last message seen in the event stream
Related events:
For more information about Server-Sent Events, read our HTML5 Server-Sent Events Tutorial.
Browser Support
The numbers in the table specify the first browser version that fully supports the event.
| Event | |||||
|---|---|---|---|---|---|
| onmessage | 9.0 | Not supported | 6.0 | 5.0 | 11.0 |
Syntax
object.onmessage = function(){myScript};
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Using the addEventListener() method:
object.addEventListener("message", myScript);
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Note: The addEventListener() method is not supported in Internet Explorer 8 and earlier versions.
Technical Details
| Bubbles: | No |
|---|---|
| Cancelable: | No |
| Event type: | Event |
More Examples
Example
Get the URL of the document that invoked the onmessage event:
var source = new EventSource("demo_sse.php");
source.onmessage = function(event) {
document.getElementById("myDIV").innerHTML = event.origin;
};
The result could be:
https://www.w3schools.com/
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