Module: Mongoid::Mirrored::RootMethods

Included in:
ClassMethods
Defined in:
lib/mongoid-mirrored/root/root_methods.rb

Instance Method Summary collapse

Instance Method Details

#define_create_mirrors ⇒ Object 



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# File 'lib/mongoid-mirrored/root/root_methods.rb', line 21

def define_create_mirrors
  unless self.instance_methods.include?(:_create_mirrors)
    self.class_eval <<-EOF
      after_create  :_create_mirrors
    EOF
  end
  define_method :_create_mirrors do
    
    # each embedded class will be touched by the callbacks
    # this should be used with care or write operations could get very slow
    embedding_models.each do |embedding_model|
      # attributes that will be used to define the root and embedding classes and instances
      embedding_string = embedding_model.to_s
      _embedding_klass = self.class.embedding_klass(embedding_model)
      embedding_instance = eval(embedding_string)

      # Only tries to create mirrored document if the embedding instance is given
      if embedding_instance
        _embedding_klass.collection.update({ :_id => embedding_instance.id }, '$push' => {self.class.root_association => attributes.except("#{embedding_string}_id")})
      end
    end
  end
end

#define_destroy_mirrors ⇒ Object 



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# File 'lib/mongoid-mirrored/root/root_methods.rb', line 81

def define_destroy_mirrors
  unless self.instance_methods.include?(:_destroy_mirrors)
    self.class_eval <<-EOF
      after_destroy  :_destroy_mirrors
    EOF
  end
  # destroys the mirrored document when the destroy method is called on the root document
  # or when the root document establishes a relationship with another embedding document
  define_method :_destroy_mirrors do |changed_embedding_instance = nil|
    embedding_models.each do |embedding_model|

      # attributes that will be used to define the root and embedding classes and instances
      embedding_string = embedding_model.to_s
      _embedding_klass = self.class.embedding_klass(embedding_model)
      embedding_instance = eval(embedding_string)
      if embedding_instance
        id_to_destroy = changed_embedding_instance || embedding_instance.id
        _embedding_klass.collection.update({ :_id => id_to_destroy }, '$pull' => {self.class.root_association => { :_id => id}})
      end
    end
  end
end

#define_root_callbacks ⇒ Object

Define callbacks for root class that don’t trigger callbacks on the mirror classes



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# File 'lib/mongoid-mirrored/root/root_methods.rb', line 5

def define_root_callbacks
  if [:both, :from_root].include?(embedding_options[:sync_direction])
    if embedding_options[:sync_events].include?(:create) || embedding_options[:sync_events] == [:all]
      define_create_mirrors
    end
    
    if embedding_options[:sync_events].include?(:update) || embedding_options[:sync_events] == [:all]
      define_update_mirrors
    end
    
    if embedding_options[:sync_events].include?(:destroy) || embedding_options[:sync_events] == [:all]
      define_destroy_mirrors
    end
  end
end

#define_update_mirrors ⇒ Object 



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# File 'lib/mongoid-mirrored/root/root_methods.rb', line 45

def define_update_mirrors
  unless self.instance_methods.include?(:_update_mirrors)
    self.class_eval <<-EOF
      before_update  :_update_mirrors
    EOF
  end
  # updates the mirrored document when one or more attributes of the parent document is changed
  # if the root document changes the embedding document, the mirrored document is deleted from the previous list
  # and another mirrored document is created for the new embedding document
  define_method :_update_mirrors do
    embedding_models.each do |embedding_model|

      # attributes that will be used to define the root and embedding classes and instances
      embedding_string = embedding_model.to_s
      embedding_instance = eval(embedding_string)
      _embedding_klass = self.class.embedding_klass(embedding_model)

      if embedding_instance
        if eval("#{embedding_string}_id_changed?")
          _create_mirrors
          _destroy_mirrors(eval("#{embedding_string}_id_was"))
        else
          # using positional modifier $ to find embedded document to be updated
          # traverses the attributes hash to inject positional modifier
          # eg: contents => ;comments.$.contents =>
          nested_attr = {}
          attributes.except("#{embedding_string}_id").each_pair do |k,v|
            nested_attr["#{self.class.root_association}.$.#{k}"] = v
          end
          _embedding_klass.collection.update({"#{self.class.root_association}._id" => id}, '$set' => nested_attr )
        end
      end
    end
  end
end

#write_fields_with_options(&block) ⇒ Object

writes the block passed to the mirrored_in method in the Root Calss defines instance methods used in callbacks triggered by the root documents



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# File 'lib/mongoid-mirrored/root/root_methods.rb', line 106

def write_fields_with_options(&block)
  index_params = ""
  index_params << ", :index => true" if embedding_options[:index]
  index_params << ", :background => true" if embedding_options[:index] && embedding_options[:background_index]
  
  embedding_models.each do |embedding_model|
    self.class_eval <<-EOT
      belongs_to :#{embedding_model} #{index_params}
    EOT
  end
  # writes shared fields and methods to root document
  yield
  
  define_root_callbacks
  
end