node-pingback

Pingbacks have come to node.js. If you're writing a blog, you may be interested in this. It conforms to the pingback specification, as well as the XML-RPC spec, however, it may need more testing.

It protects against spam, has no dependencies, and can be used right out of the box. Connect/Express middleware is included.

Usage

Receiving Pingbacks (contrived example for clarity)

app.use('/pingback',Pingback.middleware(function(source,target,next){varself=this;Posts.get(target.pathname,function(err,post){if(err){returnnext(Pingback.TARGET_DOES_NOT_EXIST);}if(post.pingbacks[source.href]){returnnext(Pingback.ALREADY_REGISTERED);}if(post.pingbacksDisabled){returnnext(Pingback.TARGET_CANNOT_BE_USED);}// or pass zero above for a generic errorpost.pingbacks.push({from: source.href,// e.g. "http://domain.tld/hey_check_out_this_guys_post"title: self.title,// e.g. "Joe's blog"text: self.excerpt// e.g. "hey, check this out: <a href="your_site">...</a>"});post.save();next();// send a success response});}));

What you see above is merely the abstracted interface of the bundled middleware. See example.js/test.js for more in-depth and lower-level examples.

Sending Pingbacks

// ping a target - err will be a fault code if presentPingback.send('[target]','[source]',function(err,pingback){if(!err)console.log('Pinged '+pingback.href+' successfully.');});// scan an html string for links to pingvartext='a link here: <a href="http://localhost:9000/article">a post</a>';Pingback.scan(text,'[source]',function(err,pingback){// optional callback - will get called for every pingback sentif(!err)console.log('Pinged '+pingback.href+' successfully.');});

Again, see example.js/test.js for more examples and explanation.

Reference

Fault Code Constants

Pingback.METHOD_NOT_FOUND=-32601;Pingback.GENERAL_ERROR=0;Pingback.SOURCE_DOES_NOT_EXIST=16;Pingback.NO_LINK_TO_TARGET=17;Pingback.TARGET_DOES_NOT_EXIST=32;Pingback.TARGET_CANNOT_BE_USED=33;Pingback.ALREADY_REGISTERED=48;Pingback.ACCESS_DENIED=49;

Pingback properties

• source: a parsed url object of the source
• target: a parsed url object of the target
• excerpt: an excerpt from the source's page
• title: the title of the source page

Events for receiving pingbacks

• ping: An optional event to validate and handle errors/faults. If bound, this will be triggered as the first event and passed a next callback, which can be passed a fault code to trigger a fault response, otherwise it will continue handling the pingback. Arguments: source, target, next.
• fault: Emitted when a fault occurs. Passed the fault code and string. Arguments: code, msg.
• error: Emitted for non-fault related errors. Calls the next middleware layer in the bundled connect/express middleware function. Arguments: err.
• end: Emitted if no ping listeners have been bound, and after a pingback has been received and verified. Arguments: source, target, next. next has the same effect as the callback passed for ping.
• success: Emitted if a ping listener was bound, and after the pingback has been received and handled. Arguments: source, target.

License

(c) Copyright 2011, Christopher Jeffrey (MIT License). See LICENSE for more info.