PubSubHubbub subscriber

PubSubHubbub subscriber module. Supports both 0.3 and 0.4 hubs. This is a fork of pubsubhubbbub with deprecated requests dependency replaced with got, callbacks replaced with promises, and turned into an ESM module.

NB Do not upgrade from v0.1.x - the API is totally different

Install

Install with npm

npm install pubsubhubbub

Usage

Create a pubsubhubbub server object

``javascript
var pubSubHubbub = require('pubsubhubbub');
var pubSubSubscriber = pubSubHubbub.createServer(options);
`

Where options includes the following properties

- callbackUrl Callback URL for the hub
- headers (optional) Custom headers to use for all HTTP requests
- secret (optional) Secret value for HMAC signatures
- leaseSeconds (optional) Number of seconds for which the subscriber would like to have the subscription active
- maxContentSize (optional) Maximum allowed size of the POST messages
- username (optional) Username for HTTP Authentication
- password (optional) Password for HTTP Authentication
- sendImmediately (optional) Send Username & Password Immediately. Defaults to false.

$3

Start a HTTP server to listen incoming PubSubHubbub requests

`javascript
// listen on port 1337
pubSubSubscriber.listen(1337);
`

$3

If you dot want to spin up a dedicated HTTP server, you can use the PubSubHubbub
subscriber as an Express middleware.

Attach PubSubHubbub object to an Express server using listener method.

`
// use the same path as defined in callbackUrl
app.use("/pubsubhubbub", pubSubSubscriber.listener());
`

Events

- 'listen' - HTTP server has been set up and is listening for incoming connections
- 'error' (_err_) - An error has occurred
- 'subscribe' (_data_) - Subscription for a feed has been updated
- 'unsubscribe' (_data_) - Subscription for a feed has been cancelled
- 'denied' (_data_) - Subscription has been denied
- 'feed' (_data_) - Incoming notification

API

$3

Start listening on selected port

pubSubSubscriber.listen(port)

Where

- port is the HTTP port to listen

$3

Subscribe to a feed with

pubSubSubscriber.subscribe(topic, hub)

Where

- topic is the URL of the RSS/ATOM feed to subscribe to
- hub is the hub for the feed

Example:

var pubSubSubscriber = pubSubHubbub.createServer(options);
var topic = "http://testetstetss.blogspot.com/feeds/posts/default";
var hub = "http://pubsubhubbub.appspot.com/";

pubSubSubscriber.on("subscribe", function(data){
console.log(data.topic + " subscribed");
});

pubSubSubscriber.listen(port);

pubsub.on("listen", async function(){
try {
await pubSubSubscriber.subscribe(topic, hub);
} catch (err) {
console.error(err);
}
});

$3

Unsubscribe from a feed with

pubSubSubscriber.unsubscribe(topic, hub)

Where

- topic is the URL of the RSS/ATOM feed to unsubscribe from
- hub is the hub for the feed

Example:

var pubSubSubscriber = pubSubHubbub.createServer(options),
topic = "http://testetstetss.blogspot.com/feeds/posts/default",
hub = "http://pubsubhubbub.appspot.com/";

pubSubSubscriber.on("unsubscribe", function(data){
console.log(data.topic + " unsubscribed");
});

pubSubSubscriber.listen(port);

pubSubSubscriber.on("listen", async function(){
try {
await pubSubSubscriber.unsubscribe(topic, hub);
} catch (err) {
console.error(err);
}
});

Notifications

Update notifications can be checked with the 'feed'` event. The data object is with the following structure:

- topic - Topic URL
- hub - Hub URL, might be undefined
- callback - Callback URL that was used by the Hub
- feed - Feed XML as a Buffer object
- headers - Request headers object

License

MIT