Module: CustomCounterCache::Model::ActsAsMethods

Defined in:
lib/custom_counter_cache/model.rb

Instance Method Summary collapse

Instance Method Details

#define_counter_cache(cache_column, &block) ⇒ Object 



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# File 'lib/custom_counter_cache/model.rb', line 9

def define_counter_cache(cache_column, &block)
  return unless table_exists?

  # counter accessors
  unless column_names.include?(cache_column.to_s)
    has_many :counters, :as => :countable, :dependent => :destroy
    define_method "#{cache_column}" do
      # check if the counter is loaded
      if counters.loaded? && counter = counters.detect{|c| c.key == cache_column.to_s }
        counter.value
      else
        counters.find_by_key(cache_column.to_s).try(:value).to_i
      end
    end
    define_method "#{cache_column}=" do |count|
      if ( counter = counters.find_by_key(cache_column.to_s) )
        counter.update_attribute :value, count.to_i
      else
        counters.create :key => cache_column.to_s, :value => count.to_i
      end
    end
  end

  # counter update method
  define_method "update_#{cache_column}" do
    if self.class.column_names.include?(cache_column.to_s)
      update_attribute cache_column, block.call(self)
    else
      send "#{cache_column}=", block.call(self)
    end
  end
end

#update_counter_cache(association, cache_column, options = {}) ⇒ Object 



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# File 'lib/custom_counter_cache/model.rb', line 42

def update_counter_cache(association, cache_column, options = {})
  return unless table_exists?

  association  = association.to_sym
  cache_column = cache_column.to_sym
  method_name  = "callback_#{cache_column}".to_sym
  reflection   = reflect_on_association(association)
  foreign_key  = reflection.options[:foreign_key] || reflection.association_foreign_key

  # define callback
  define_method method_name do
    # update old association
    if send("#{foreign_key}_changed?") || ( reflection.options[:polymorphic] && send("#{association}_type_changed?") )
      old_id = send("#{foreign_key}_was")
      klass = if reflection.options[:polymorphic]
        ( send("#{association}_type_was") || send("#{association}_type") ).constantize
      else
        reflection.klass
      end
      if ( old_id && record = klass.find(old_id) )
        record.send("update_#{cache_column}")
      end
    end
    # update new association
    if ( record = send(association) )
      record.send("update_#{cache_column}")
    end
  end

  # set callbacks
  after_create  method_name, options
  after_update  method_name, options
  after_destroy method_name, options
end