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Class: ActiveRecord::Associations::BelongsToPolymorphicAssociation

Do not use. This class is for internal use only.

Overview

Active Record Belongs To Polymorphic Association

Class Method Summary

Association - Inherited

.new

Instance Attribute Summary

BelongsToAssociation - Inherited

#saved_change_to_target?, #target_changed?, #target_previously_changed?, #updated?, #find_target?, #foreign_key_present?, #require_counter_update?

Association - Inherited

#collection?

Whether the association represent a single record or a collection of records.
#disable_joins,
#loaded?

Has the target been already loaded?
#options, #owner, #reflection,
#stale_target?

The target is stale if the target no longer points to the record(s) that the relevant foreign_key(s) refers to.
#target,
#target=

Sets the target of this association to \target, and the loaded flag to true.
#find_target?,
#foreign_key_present?

Returns true if there is a foreign key present on the owner which references the target.
#violates_strict_loading?

Instance Method Summary

BelongsToAssociation - Inherited

#decrement_counters, #decrement_counters_before_last_save, #default, #handle_dependency, #increment_counters, #inversed_from, #reset, #invertible_for?, #primary_key, #replace, #replace_keys, #stale_state, #update_counters, #update_counters_via_scope

SingularAssociation - Inherited

#build,
#force_reload_reader

Implements the reload reader method, e.g.
#reader

Implements the reader method, e.g.
#reset

Resets the loaded flag to false and sets the target to nil.
#writer

Implements the writer method, e.g.
#_create_record, #find_target, #replace, #scope_for_create, #set_new_record

Association - Inherited

#async_load_target, #create, #create!, #extensions, #initialize_attributes, #inversed_from, #inversed_from_queries,
#klass

Returns the class of the target.
#load_target

Loads the target if needed and returns it.
#loaded!

Asserts the target has been loaded setting the loaded flag to true.
#marshal_dump

We can’t dump @reflection and @through_reflection since it contains the scope proc.
#marshal_load,
#reload

Reloads the target and returns self on success.
#remove_inverse_instance

Remove the inverse association, if possible.
#reset

Resets the loaded flag to false and sets the target to nil.
#reset_negative_cache, #reset_scope, #scope,
#set_inverse_instance

Set the inverse association, if possible.
#set_inverse_instance_from_queries, #set_strict_loading,
#association_scope

The scope for this association.
#build_record, #enqueue_destroy_association,
#ensure_klass_exists!

Reader and writer methods call this so that consistent errors are presented when the association target class does not exist.
#find_target,
#foreign_key_for?

Returns true if record contains the foreign_key.
#inversable?, #inverse_association_for,
#inverse_reflection_for

Can be redefined by subclasses, notably polymorphic belongs_to The record parameter is necessary to support polymorphic inverses as we must check for the association in the specific class of the record.
#invertible_for?

Returns true if inverse association on the given record needs to be set.
#matches_foreign_key?,
#raise_on_type_mismatch!

Raises ::ActiveRecord::AssociationTypeMismatch unless record is of the kind of the class of the associated objects.
#scope_for_create,
#skip_statement_cache?

Returns true if statement cache should be skipped on the association reader.
#skip_strict_loading,
#stale_state

This should be implemented to return the values of the relevant key(s) on the owner, so that when stale_state is different from the value stored on the last find_target, the target is stale.
#target_scope

Can be overridden (i.e. in ThroughAssociation) to merge in other scopes (i.e.

Constructor Details

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

Instance Attribute Details

#saved_change_to_target? ⇒ Boolean (readonly)

[ GitHub ] 

  


# File 'activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb', line 20



def saved_change_to_target?
  super || owner.saved_change_to_attribute?(reflection.foreign_type)
end


  








  

    #target_changed?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb', line 12



def target_changed?
  super || owner.attribute_changed?(reflection.foreign_type)
end


  








  

    #target_previously_changed?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb', line 16



def target_previously_changed?
  super || owner.attribute_previously_changed?(reflection.foreign_type)
end


  







Instance Method Details



  

    #inverse_reflection_for(record)   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb', line 35



def inverse_reflection_for(record)
  reflection.polymorphic_inverse_of(record.class)
end


  








  

    #klass  
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb', line 7



def klass
  type = owner[reflection.foreign_type]
  type.presence && owner.class.polymorphic_class_for(type)
end


  








  

    #raise_on_type_mismatch!(record)   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb', line 39



def raise_on_type_mismatch!(record)
  # A polymorphic association cannot have a type mismatch, by definition
end


  








  

    #replace_keys(record, force: false)   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb', line 25



def replace_keys(record, force: false)
  super

  target_type = record ? record.class.polymorphic_name : nil

  if force || owner._read_attribute(reflection.foreign_type) != target_type
    owner[reflection.foreign_type] = target_type
  end
end


  








  

    #stale_state   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb', line 43



def stale_state
  if foreign_key = super
    [foreign_key, owner[reflection.foreign_type]]
  end
end