Content Syndication with Node.js

Web syndication is a must for any Website wishing to share some entries easily to other systems. Better known under their format name like RSS) or Atom), they can be quite time consuming to generate without a module handling all their formating. Thanks to the power of Node's package manager NPM, you can generate yours in no time.

Installing the feed wrapper

Before we start, head to your project folder and install the latest version of the module feed:

$ npm install feed

Building the feed

First, we need to initialize a new Feed object. When you initialize the object, you must provide general information related to your Web syndication feed.

// Require module
var Feed = require('feed');

// Initializing feed object
var feed = new Feed({
    title:          'My Feed Title',
    description:    'This is my personnal feed!',
    link:           'http://example.com/',
    image:          'http://example.com/logo.png',
    copyright:      'Copyright © 2013 John Doe. All rights reserved',

    author: {
        name:       'John Doe',
        email:      'john.doe@example.com',
        link:       'https://example.com/john-doe'
    }
});

Second, you might want to identify your feed thematic. Both RSS) and Atom) formats offer the possibility to identify one or multiple categories. Again, this is super simple to add:

feed.category('Node.js');
feed.category('JavaScript');

Third, every feed require at least one item (better known as an entry). To do so, you have to use the function item and provide the proper object. Of course, if you are running a content Website (like a blog!), chances are that you have multiple items. To populate your feed, use a for loop as followed:

for(var key in posts) {
    feed.item({
        title:          posts[key].title,
        link:           posts[key].url,
        description:    posts[key].description,
        date:           posts[key].date
    });
}

At this point, everything is ready to generate your RSS) or Atom feed. Use the function render:

var output = feed.render();

This is the implicit way of calling the render request. By default, it will render a RSS) feed. You an also use the explicit way, allowing you to select between RSS) or Atom):

// Rendering a RSS 2.0 valid feed
feed.render('rss-2.0');

// Rendering an Atom 1.0 valid feed
feed.render('atom-1.0');

Yes, it's that simple!

Using with Express.js

Using feed with Express.js is super easy. Let's say you have an app.get() method routing the path /rss. To send your feed, render your feed like we mentionned previously. After, send the result by setting the proper Content-Type to text/xml:

app.get('/rss', function(req, res) {

    // Initializing feed object
    var feed = new Feed({
        title:          'My Feed Title',
        description:    'This is my personnal feed!',
        link:           'http://example.com/',
        image:          'http://example.com/logo.png',
        copyright:      'Copyright © 2013 John Doe. All rights reserved',

        author: {
            name:       'John Doe',
            email:      'john.doe@example.com',
            link:       'https://example.com/john-doe'
        }
    });

    // Function requesting the last 5 posts to a database. This is just an
    // example, use the way you prefer to get your posts.
    Post.findPosts(function(posts, err) {
        if(err)
            res.send('404 Not found', 404);
        else {
            for(var key in posts) {
                feed.item({
                    title:          posts[key].title,
                    link:           posts[key].url,
                    description:    posts[key].description,
                    date:           posts[key].date
                });
            }
            // Setting the appropriate Content-Type
            res.set('Content-Type', 'text/xml');

            // Sending the feed as a response
            res.send(feed.render('rss-2.0'));
        }
    });
});

Conclusion

There you go, it was super duper easy :)! Now, people can finally read your entries feeded from your Node.js application!