The code for this site is available to the many-eyes beasts of the Interwebs here:

It requires merb and friends, as well as an instance of CouchDB to be running somewhere. There are a few reasons I chose merb over Rails (which is what I generally use professionally) to do this:

• It comes with no pre-packaged ORM. I wanted to use CouchDB, so none of the existing ORMs would really work for me. My previous experiences of trying to rip ActiveRecord out of Rails have been frustrating.
• It has more flexible routing than Rails. I realize there are ways to accomplish the things I’m doing here in Rails, but the merb routes seem clearer to me, less hand-wavy. And perhaps most importantly:
• It’s not Rails. I use Rails all day long, and I wanted to see what else is out there.

Moving along. I’m using CouchObject to communicate between Ruby and CouchDB, but I found CouchObject’s Persistable API a little unsatisfying, so I wrapped in a class I’m calling CouchBase. Classes that extend CouchBase can define couch_accessors that are populated from, and saved to, CouchDB.

class Post < CouchBase 
  couch_accessor :title, :summary, :body, :author, :tags, :created_at
  ...
end

def self.couch_accessor(*fields)
  meta_def(:couchables) { fields }
end

This just takes note of which attributes should be saved in CouchDB because this can’t be inspected from a schema like with ActiveRecord. The method meta_def is part of metaid. When any of these attributes is read from or written to, it’s actually the class’s @document that is accessed.

def method_missing(meth, *attrs)
  field = meth.to_s.gsub('=', '')
  proxied_methods = self.class.couchables + [ :id, :new? ]
  if proxied_methods.include?(field.to_sym)
    @document.send(meth, *attrs) rescue nil
  else
    super
  end
end

Then, if the object is save-ed that @document is written to CouchDB. Objects pulled from the DB via CouchObject#find_by_id have their @document populated from the CouchDB record.

One caveat I noticed using CouchObject: CouchDB expects temp view POSTs to have the mime-type “text/javascript” but CouchObject sends them as “application/json” so you have to add application/json=/usr/local/bin/couchjs -f /usr/local/share/couchdb/server/main. js to the end of your /usr/local/etc/couchdb/couch.ini.

I’ll try to get comments working soon so people who want to blab may do so. In the mean time you can write to me at gnarg@slackworks.com and don’t forget to check out the code.