Code snippets for http://ryanfunduk.com/fun-with-couchdb

1.js

// Note: The functions should be wrapped in "double quotes" the
//       same as the keys, I've removed them here for syntax
//       highlighting purposes.

{
  "_id": "_design/ratings",
  "views": {
    "by_permalink": {
      "reduce": function( keys, values ) {
        return sum( values ) / values.length;
      },
      "map": function( doc ) {
        if( doc.type == 'rating' ) emit( doc.permalink, doc.rating );
      }
    }
  }
}

2.js

{
  "rows": [
    { "key": "forcing-scrollbars",  "value": average-rating },
    { "key": "moving-to-passenger", "value": average-rating },
    { "key": "simple-partials",     "value": average-rating },
    { "key": "talking-about-dvcs",  "value": average-rating },
    ...
  ]
}

3.rb

require 'rubygems'
require 'sinatra'
require 'rest_client'
require 'json'

DB = 'http://localhost:5984/rf'

get '/get_ratings/:permalink' do
  data = RestClient.get "#{DB}/_view/ratings/by_permalink?group=true"
  result = JSON.parse( data )['rows'].select do |row|
    row if row['key'] == params[:permalink]
  end

  result.first['value'].to_s unless result.empty?
end

post '/rate/:permalink/:rating' do
  doc_url = "#{DB}/#{params[:permalink]}"
  rev = JSON.parse( RestClient.get( doc_url ) )['_rev'] rescue nil

  new_doc = {
    'permalink' => params[:permalink],
    'rating' => params[:rating].to_i,
    'type' => 'rating'
  }
  new_doc['_rev'] = rev if rev

  RestClient.put doc_url, new_doc.to_json,
                 :content_type => 'application/json'
end

4.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'rest_client'
require 'json'

DB = "http://localhost:4567/api"

if ARGV.first == 'put'
  permalink, rating = ARGV.pop 2
  puts RestClient.post "#{DB}/rate/#{permalink}/#{rating}", ''
else
  permalink = ARGV.pop
  puts RestClient.get "#{DB}/get_ratings/#{permalink}"
end

5.txt

$ ruby dbtest.rb put awesome-post 5
{"ok":true,"id":"awesome-post","rev":"3451438800"}
$ ruby dbtest.rb get awesome-post
5

6.js

$(document).ready( function() {
  // ... some other code ...
  if( $.fn.rater ) { $('#some_element').rater( opts ); }
} );