gistfile1.rb

module Formol
  class Post < ActiveRecord::Base
    #Security
    attr_protected :topic_id, :user_id, :created_by_topic
    
    #Virtual attributes
    attr_accessor :created_by_topic, :quote_id, :register_user_as_subscriber
    
    #Default values
    default_value_for :created_by_topic, false
    default_value_for :display_signature do |p|
      p.user ? p.user.preference.use_signature : true
    end
    
    #Associations
    belongs_to  :topic, :touch          => true,
                        :counter_cache  => true
    belongs_to  :user,  :class_name     => Formol.config.user_class,
                        :counter_cache  => :formol_posts_count
    
    has_one     :forum, :through        => :topic
    
    #Validations
    validates :topic,   :presence => true
    validates :user,    :presence => true
    #Length is set with a minimum of 2 to allow posts with simple "ok" answer
    #Length is set with a maximum of 50 000 because 50Kb is enough for a non
    #binary forum
    validates :content, :presence => true,
                        :length   => {  :in           => 2..50_000,
                                        :allow_blank  => true }
                                      
    validate  :validates_topic_not_locked
    
    #Normalization
    normalize_attribute :content, :with => [:strip, :blank]
    
    #Callbacks
    after_initialize  :feed_content_with_quote
    
    after_save        :register_author_as_subscriber
    after_create      :increment_forum_counter_cache,
                      :register_as_last_post_on_topic,
                      :register_as_last_post_on_forum
    after_destroy     :decrement_forum_counter_cache,
                      :unregister_as_last_post_on_topic,
                      :unregister_as_last_post_on_forum
    
    #Scopes
    class << self
      # scope for ordering posts conveniently for listing views
      # order by id (no order is random with mysql)
      def ordered_for_listing
        order('formol_posts.id ASC')
      end
      
      # scope to get posts conveniently prepared for listing
      def ready_for_listing
        ordered_for_listing.includes(:topic, { :user => :preference })
      end
      
      # scope to get last five posts with reverse ordering
      # usefull to have a little history when replying to a topic
      def last_fives
        order('formol_posts.id DESC').limit(5).includes(:user)
      end
    end
    
    #Business methods
    
    # Read accessor for 'register_user_as_subscriber'
    def register_user_as_subscriber(force_recompute = false)
      if @register_user_as_subscriber.nil? || force_recompute
        @register_user_as_subscriber = compute_register_subscribing
      end
      
      @register_user_as_subscriber
    end
    
    private
    
    # Convert 'register_user_as_subscriber' to boolean
    def register_user_as_subscriber?
      [true, '1', 'true'].include?(register_user_as_subscriber)
    end
    
    #Callback methods
    
    # Registers author as subscriber if he's not already
    def register_author_as_subscriber
      if register_user_as_subscriber? 
        topic.register_subscriber(user) unless topic.subscriber?(user)
      else
        topic.unregister_subscriber(user) if topic.subscriber?(user)
      end
    end
    
    # Validates topic is not locked
    # If topic is locked, it will add an error on base (not on topic)
    # This validation does not trigger on first post
    def validates_topic_not_locked
      errors.add(:base, :topic_locked) if topic.locked? && !created_by_topic
    end
    
    # Holds counter cache on Forum till AR does not support it on has_one
    def increment_forum_counter_cache
      Formol::Forum.increment_counter(:posts_count, forum.id) if forum.present?
    end
    
    # Holds counter cache on Forum till AR does not support it on has_one
    def decrement_forum_counter_cache
      Formol::Forum.decrement_counter(:posts_count, forum.id) if forum.present?
    end
    
    # Feed content with quote's content
    # If you're trying to pass quote_id in a POST, your content will be wiped
    # Too bad!
    def feed_content_with_quote
      return true if quote_id.blank?
      
      q = topic.posts.find(quote_id)
      formatter = Formol.config.formatter.new

      # Extract and agnostize it
      content_with_quote = "> **#{q.user.display_name} #{I18n.t('.wrote')}:**\n>\n"
      content_with_quote << formatter.quote(q.content)
      
      self.content = content_with_quote
      self.content << "\n\n" #use '<<' to skip normalize_attribute
      self.content
    end
    
    # Register current post being the last of its topic
    def register_as_last_post_on_topic
      topic.register_last_post(self)
    end
    
    # Unregister current post being the last of its topic
    def unregister_as_last_post_on_topic
      topic.unregister_last_post if topic.last_post == self
    end
    
    # Register current post being the last post of its forum
    def register_as_last_post_on_forum
      forum.register_last_post(self)
    end
    
    # Unregister current post being the last of its forum
    def unregister_as_last_post_on_forum
      forum.unregister_last_post if forum.last_post == self
    end
    
    # Computes 'register_user_as_subscriber
    def compute_register_subscribing
      if topic && user
        topic.subscriber?(user)
      else
        false
      end
    end
  end
end