Class: ActiveNode::Associations::CollectionAssociation

Inherits:
Association
  • Object
show all
Defined in:
lib/active_node/associations/collection_association.rb

Overview

Active Record Association Collection

CollectionAssociation is an abstract class that provides common stuff to ease the implementation of association proxies that represent collections. See the class hierarchy in AssociationProxy.

CollectionAssociation:
  HasAndBelongsToManyAssociation => has_and_belongs_to_many
  HasManyAssociation => has_many
    HasManyThroughAssociation + ThroughAssociation => has_many :through

CollectionAssociation class provides common methods to the collections defined by has_and_belongs_to_many, has_many or has_many with :through association option.

You need to be careful with assumptions regarding the target: The proxy does not fetch records from the database until it needs them, but new ones created with build are added to the target. So, the target may be non-empty and still lack children waiting to be read from the database. If you look directly to the database you cannot assume that’s the entire collection because new records may have been added to the target, etc.

If you need to work on all current children, new and existing records, load_target and the loaded flag are your friends.

Direct Known Subclasses

HasManyAssociation

Instance Attribute Summary

Attributes inherited from Association

#owner, #reflection, #target

Instance Method Summary collapse

Methods inherited from Association

#initialize, #klass, #load_target, #reader, #save, #writer

Constructor Details

This class inherits a constructor from ActiveNode::Associations::Association

Instance Method Details

#ids_reader ⇒ Object

Implements the ids reader method, e.g. foo.item_ids for Foo.has_many :items



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# File 'lib/active_node/associations/collection_association.rb', line 30

def ids_reader
  reader.map(&:id)
end

#ids_writer(ids) ⇒ Object

Implements the ids writer method, e.g. foo.item_ids= for Foo.has_many :items



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# File 'lib/active_node/associations/collection_association.rb', line 35

def ids_writer(ids)
  writer klass.find(ids.reject(&:blank?).map!(&:to_i))
end

#reset ⇒ Object 



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# File 'lib/active_node/associations/collection_association.rb', line 43

def reset
  super
  @target = owner.new_record? ? [] : nil
  @dirty = false
end

#target_each ⇒ Object 



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# File 'lib/active_node/associations/collection_association.rb', line 39

def target_each
  target.each {|n| yield n}
end