Module: CustomCounterCache::Model::ClassMethods

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 7

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

rescue StandardError => e
  # Support Heroku's database-less assets:precompile pre-deploy step:
  raise e unless ENV['DATABASE_URL'].to_s.include?('//user:[email protected]/')
end

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



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# File 'lib/custom_counter_cache/model.rb', line 44

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_#{association}_#{cache_column}".to_sym
  reflection   = reflect_on_association(association)
  foreign_key  = reflection.try(:foreign_key) || reflection.association_foreign_key

  # define callback
  define_method method_name do
    # update old association
    rails_5_1_or_newer = ActiveModel.version >= Gem::Version.new('5.1.0')
    target_key = reflection.options[:polymorphic] ? "#{association}_type" : foreign_key
    target_changed = rails_5_1_or_newer ? send("saved_change_to_#{target_key}?") : send("#{target_key}_changed?")
    if target_changed
      old_id = rails_5_1_or_newer ? send("#{target_key}_before_last_save") : send("#{target_key}_was")
      klass = if reflection.options[:polymorphic]
        ( old_id || send("#{association}_type") ).constantize
      else
        reflection.klass
      end
      if ( old_id && record = klass.find_by(id: old_id) )
        record.send("update_#{cache_column}")
      end
    end
    # update new association
    if ( record = send(association) )
      record.send("update_#{cache_column}")
    end
  end

  skip_callback = Proc.new { |callback, opts|
    (opts[:except].present? && opts[:except].include?(callback)) ||
    (opts[:only].present?   && !opts[:only].include?(callback))
  }

  # set callbacks
  after_create  method_name, options unless skip_callback.call(:create, options)
  after_update  method_name, options unless skip_callback.call(:update, options)
  after_destroy method_name, options unless skip_callback.call(:destroy, options)

rescue StandardError => e
  # Support Heroku's database-less assets:precompile pre-deploy step:
  raise e unless ENV['DATABASE_URL'].to_s.include?('//user:[email protected]/')
end