Baseline Widely available
Note: This feature is available in Web Workers.
The message
event of the EventSource
interface is fired when data is received through an event source.
This event is not cancelable and does not bubble.
SyntaxUse the event name in methods like addEventListener()
, or set an event handler property.
addEventListener("message", (event) => { })
onmessage = (event) => { }
Event type Event properties
This interface also inherits properties from its parent, Event
.
MessageEvent.data
Read only
The data sent by the message emitter.
MessageEvent.origin
Read only
A string representing the origin of the message emitter.
MessageEvent.lastEventId
Read only
A string representing a unique ID for the event.
MessageEvent.source
Read only
A MessageEventSource
(which can be a WindowProxy, MessagePort
, or ServiceWorker
object) representing the message emitter.
MessageEvent.ports
Read only
An array of MessagePort
objects representing the ports associated with the channel the message is being sent through (where appropriate, e.g., in channel messaging or when sending a message to a shared worker).
In this basic example, an EventSource
is created to receive events from the server; a page with the name sse.php
is responsible for generating the events.
const evtSource = new EventSource("sse.php");
const eventList = document.querySelector("ul");
evtSource.addEventListener("message", (e) => {
const newElement = document.createElement("li");
newElement.textContent = `message: ${e.data}`;
eventList.appendChild(newElement);
});
onmessage equivalent
evtSource.onmessage = (e) => {
const newElement = document.createElement("li");
newElement.textContent = `message: ${e.data}`;
eventList.appendChild(newElement);
};
Specifications Browser compatibility See also
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4