yaj-sse
v0.3.0
Published
Yaj Plugin for Server-Sent Events (SSE) EventSource Polyfill
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Yaj SSE
A lightweigth (<2kb) Yaj Plugin for Server-Sent Events (SSE) EventSource Polyfill. This plugin try to use the native EventSource object if it supported by the browser. If there is no native support the request is made by ajax requests (polling). You do not need to change the server side nor the client side.
Example
Client Side
var sse = new SSE('http://example.com/sse-server.php', {
onMessage: function(e){
console.log("Message"); console.log(e);
}
});
sse.start();
Server Side
echo "data: My Message\n";
echo "\n";
Dependencies
- Yaj (only for ajax fallback)
Install
Just download the repository and point to the Yaj plugin:
<script src="yaj-sse.js" ></script>
or
<script src="yaj-sse.min.js" ></script>
You can also install using yarn:
yarn add yaj-sse
Usage:
Constructor
var sse = new SSE(url, settings);
- url: URL for the server will be sent the events to this page;
- settings: The events and options for the SSE instance
Settings List
All the options:
var sseObject = new SSE('sse-server.php', {
onOpen: function (e) {},
onEnd: function (e) {},
onError: function (e) {},
onMessage: function (e) {},
options: {},
headers: {},
events: {}
});
Event onOpen
Fired when the connection is opened the first time;
onOpen: function(e){
console.log("Open"); console.log(e);
},
Event onEnd
Fired when the connection is closed and the client will not listen for the server events;
onEnd: function(e){
console.log("End"); console.log(e);
},
Event onError
Fired when the connection error occurs;
onError: function(e){
console.log("Could not connect");
},
Event onMessage
Fired when the a message without event is received
onMessage: function(e){
console.log("Message"); console.log(e);
},
Custom Options
Define the options for the SSE instance
options: {
forceAjax: false
},
- forceAjax: Uses ajax even if the EventSource object is supported natively;
Custom Events
Fired when the server set the event and match with the key
For example, if you have a custom event called myEvent
you may use the follow code:
events: {
myEvent: function(e) {
console.log('Custom Event');
console.log(e);
}
}
Server side:
echo "event: myEvent\n"; // Must match with events in the HTML.
echo "data: My Message\n";
echo "\n";
Custom Headers
You can send custom headers to the request.
headers: {
'Authorization', 'Bearer 1a234fd4983d'
}
Note: As the EventSource does not support send custom headers to the request, the object will fallback automatically to 'forceAjax=true', even this it is not set.
Methods
start
Start the EventSource communication
sse.start();
stop
Stop the EventSource communication
sse.stop();
Quirks
The ajax does not support the streaming as the event source supports. In that case we recommend create a server without streaming and set the "retry" to determine query frequency;
Example Server Side:
echo "retry: 3000\n";
echo "data: My Message\n";
echo "\n";
Minify
npm run minify
Running the examples
Start the webserver:
docker run -it --rm -p 8080:80 -v $PWD:/var/www/html byjg/php:7.4-fpm-nginx
Open the browser: http://localhost:8080/examples/sse-client.html
References
- http://www.w3.org/TR/2009/WD-eventsource-20091029/
- https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events
- http://html5doctor.com/server-sent-events/
- http://www.html5rocks.com/en/tutorials/eventsource/basics/