Module: DataMapper::Is::CounterCacheable::ClassMethods

Defined in:
lib/dm-is-counter_cacheable/is/counter_cacheable.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#counter_cache ⇒ Object (readonly)

Returns the value of attribute counter_cache.



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# File 'lib/dm-is-counter_cacheable/is/counter_cacheable.rb', line 13

def counter_cache
  @counter_cache
end

Instance Method Details

#counter_cacheable(relationship_name, options = {}) ⇒ DataMapper::Property

Adds a counter cache property to a related model.

Parameters:

  • relationship_name (Symbol) —

    The name of the related model.

  • options (Hash) (defaults to: {}) —

    Additional options.

Options Hash (options):

  • :counter_property (Symbol) —

    The optional property name to store the counter cache in.

  • :counter_index (Boolean) —

    Specifies to store the current count in newly created resources.

Returns:

  • (DataMapper::Property) —

    The newly added counter cache property.



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# File 'lib/dm-is-counter_cacheable/is/counter_cacheable.rb', line 33

def counter_cacheable(relationship_name,options={})
  @counter_cache ||= []

  unless self.relationships.named?(relationship_name)
    raise(RuntimeError,"unknown relationship #{relationship_name} in #{self}",caller)
  end

  model_name = DataMapper::NamingConventions::Resource::UnderscoredAndPluralized.call(self.name.split('::').last)
  counter_property = if options.has_key?(:counter_property)
                       options[:counter_property]
                     else
                       :"#{model_name}_counter"
                     end

  relationship = self.relationships[relationship_name]
  parent_model = case relationship
                 when DataMapper::Associations::ManyToOne::Relationship,
                      DataMapper::Associations::OneToOne::Relationship
                   relationship.parent_model
                 end

  parent_model.property counter_property, Integer, :default => 0, :min => 0

  if options[:counter_index]
    counter_index = :"#{relationship_name}_#{model_name}_index"

    self.property counter_index, Integer, :min => 1
  else
    counter_index = nil
  end

  @counter_cache << {
    :relationship => relationship_name,
    :counter_property => counter_property,
    :counter_index => counter_index
  }
end