post.rb

class Question < CouchRest::Model
  key_accessor :q, :a
end

class Person < CouchRest::Model
  key_accessor :name
  def last_name
    name.last
  end
end

class Course < CouchRest::Model
  key_accessor :title
  cast :questions, :as => ['Question']
  cast :professor, :as => 'Person'
  view_by :title
end

class Post < CouchRest::Model
  # This sets the _id of the document if it is not already set.
  # It will only run once so in this case if the slug changes, 
  # the _id will stay the same.
  # 
  # uniq_id works using the callback mechanism, always comes as the 
  # last before_create callback.
  # 
  # unique_id :slug
  # 
  # or provide a lambda
  unique_id do |post|
    post.slug
  end
  
  
  # Creates a view like:
  # function(doc) {
  #   if (doc.type == 'Post' && doc.slug) {
  #     emit(doc.slug, null);
  #   }
  # }
  # 
  # To load Post documents by slug, call:
  # Post.by_slug :key => 'my-slug'
  # 
  # View methods will always return an array of Posts. To load a single Post, use Post.get(id)
  # 
  # To load Post view-rows by slug, call:
  # Post.by_slug :key => 'my-slug', :raw => true
  view_by :slug
  view_by :date
  
  
  # Creates a view like:
  # function(doc) {
  #   if (doc.type == 'Post' && doc.user_id && doc.date && doc.body) {
  #     emit([doc.user_id, doc.date], doc.body);
  #   }
  # }
  # 
  # Defines a method (note that default for this one is to return the raw view rows without docs):
  # Post.by_user_id_and_date :startkey => [current_user.id], :endkey => [current_user.id, {}]
  # 
  # Sugared version of the same query?
  # Post.by_user_id_and_date :user_id => current_user.id, :date => :all
  view_by :user_id, :date, :value => :body, :raw => true

  
  # Define a custom view.
  # To load posts tagged 'cooking':
  # Post.by_tags :key => 'cooking'
  # 
  # To get the raw view results:
  # Post.by_tags :key => 'cooking', :raw => true
  # 
  # To run the reduce (always raw, default is group=true)
  # Post.by_tags :reduce => true, :group => false
  view_by :tags, 
    :map => 
      "function(doc) {
        if (doc.type == 'Post' && doc.tags) {
          doc.tags.forEach(function(tag){
            emit(doc.tag, 1);
          });
        }
      }",
    :reduce => 
      "function(keys, values, rereduce) {
        return sum(values);
      }"
    
  # Can we use someone else's code to define the callback system?
  before_create :generate_slug_from_title
  def generate_slug_from_title
    @doc['slug'] = self.title.downcase.gsub(/[^a-z0-9]/,'-').squeeze('-').gsub(/^\-|\-$/,'')
  end

  # Instance methods
  
  key_accessor :title, :body, :user_id
  key_reader :slug
  
  # You can make dates work nice without magic or special fields
  key_writer :date 
  def date
    Time.parse(@doc['date'])
  end
  
end