Express Accept Events

A Connect/Express style middleware to parse the Accept-Events header field specified in Per Resource Events.

Installation

Install Express Accept Events using your favourite package manager.

npm|pnpm|yarn|bun add express-accept-events

Usage

In case one is using an Express server:

import AcceptEvents from "express-accept-events";
const app = express();
app.use(acceptEvents);

The middleware populates req.acceptEvents with a list of notification protocols and their corresponding parameters (sorted by the value of a q parameter, if provided) in GET and POST requests. For Example, the following HTTP request:

GET /notifications HTTP/1.1
Host: example.com
Accept: text/plain
Accept-Events: "prep"; accept="message/rfc822"; q=0.9, "solid"; type="WebSocket2023"

with the GET handler, so specified:

app.get("/foo", (req, res) => {
  console.log(req.acceptEvents);
});

will result in the output:

[
  [ "solid", Map(1) { "type" => "WebSocket2023" } ]
  [ "prep", Map(2) { "accept" => "message/rfc822", "q" => 0.9 } ]
]

Errors

In case the middleware fails to parse the Accept-Events header field, the req.acceptEvents property is not created.

Copyright and License

Copyright © 2024, Rahul Gupta and Express Accept Events contributors.

The source code in this repository is released under the Mozilla Public License v2.0.