Auto-prepending links in RSS feeds with your domain (on Radiant)

When you syndicate Radiant content, you may hit the problem of internal links, or img src attributes pointing to invalid paths on a syndicator's domain. So, for example, an aggregator may link to http://aggregator.com/about-us instead of http://your-site.com/about-us. The simple fix is ofcourse to use absolute URLs for all your href and src attributes, but that is not default behavior in Radiant (or most CMSes as far as i know).

If you are using paperclipped, and use <r:asset /> tags to display images, you could fix their src attributes in script console or via the Settings extension by doing:

Radiant::Config["assets.url"] = "http://your-site.com/:class/:id/:basename:no_original_style.:extension"

But that still leaves you with the fact that <r:url />, <r:link /> and some other radius tags output relative urls. Heck, you may even have a few clients that are smart enough to write urls by hand! Here's a method that will convert all relative URLs to absolute ones;

def fix_for_syndication(text, host)   text.gsub(/href=('|")([^(http:|mailto:)].*?)('|")/,
    'href="' + host + '\2"').gsub(/src=('|")([^http:].*?)('|")/, 'src="' +
    host + '\2"') end

From there you can make a simple radius tag to use where-ever you output stuff to an RSS feed;

tag 'fix_links_for_syndication' do |tag|   fix_for_syndication(tag.expand,
    "#{tag.globals.page.request.protocol}#{tag.globals.page.request.host_with_port}")
    end

I used this in one of our own extensions (works-for-us'ish), use at your own risk; probably not compatible with the standard 'blog' extension for example.