@hn3000/eventsource
v1.0.8-hn3000
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W3C compliant EventSource client for Node.js and browser (polyfill)
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EventSource
This library is a pure JavaScript implementation of the EventSource client. The API aims to be W3C compatible.
You can use it with Node.js or as a browser polyfill for
browsers that don't have native EventSource
support.
Forked for fixes to reconnect issues
This fork exists because the original has not been published, yet, after PRs #125, #126 and #136 have been merged that fix a critical issue for me.
This fork is published as @hn3000/eventsource. It should go away once upstream update their package.
Install
npm install eventsource
Example
npm install
node ./example/sse-server.js
node ./example/sse-client.js # Node.js client
open http://localhost:8080 # Browser client - both native and polyfill
curl http://localhost:8080/sse # Enjoy the simplicity of SSE
Browser Polyfill
Just add example/eventsource-polyfill.js
file to your web page:
<script src=/eventsource-polyfill.js></script>
Now you will have two global constructors:
window.EventSourcePolyfill
window.EventSource // Unchanged if browser has defined it. Otherwise, same as window.EventSourcePolyfill
If you're using webpack or browserify
you can of course build your own. (The example/eventsource-polyfill.js
is built with webpack).
Extensions to the W3C API
Setting HTTP request headers
You can define custom HTTP headers for the initial HTTP request. This can be useful for e.g. sending cookies
or to specify an initial Last-Event-ID
value.
HTTP headers are defined by assigning a headers
attribute to the optional eventSourceInitDict
argument:
var eventSourceInitDict = {headers: {'Cookie': 'test=test'}};
var es = new EventSource(url, eventSourceInitDict);
Allow unauthorized HTTPS requests
By default, https requests that cannot be authorized will cause the connection to fail and an exception to be emitted. You can override this behaviour, along with other https options:
var eventSourceInitDict = {https: {rejectUnauthorized: false}};
var es = new EventSource(url, eventSourceInitDict);
Note that for Node.js < v0.10.x this option has no effect - unauthorized HTTPS requests are always allowed.
HTTP status code on error events
Unauthorized and redirect error status codes (for example 401, 403, 301, 307) are available in the status
property in the error event.
es.onerror = function (err) {
if (err) {
if (err.status === 401 || err.status === 403) {
console.log('not authorized');
}
}
};
HTTP/HTTPS proxy
You can define a proxy
option for the HTTP request to be used. This is typically useful if you are behind a corporate firewall.
var es = new EventSource(url, {proxy: 'http://your.proxy.com'});
License
MIT-licensed. See LICENSE