Class: ActiveRecord::Reflection::AssociationReflection

Inherits:
MacroReflection show all
Defined in:
activerecord/lib/active_record/reflection.rb

Overview

Holds all the metadata about an association as it was specified in the Active Record class.

Instance Attribute Summary collapse

Attributes inherited from MacroReflection

#active_record, #name, #options, #plural_name, #scope

Instance Method Summary collapse

Methods inherited from MacroReflection

#==, #autosave=, #klass, #scope_for

Methods inherited from AbstractReflection

#alias_candidate, #build_association, #build_scope, #chain, #check_validity_of_inverse!, #class_name, #constraints, #counter_cache_column, #counter_must_be_updated_by_has_many?, #has_cached_counter?, #inverse_of, #inverse_updates_counter_in_memory?, #inverse_which_updates_counter_cache, #join_scope, #join_scopes, #klass_join_scope, #scopes, #strict_loading?, #strict_loading_violation_message, #table_name, #through_reflection?

Constructor Details

#initialize(name, scope, options, active_record) ⇒ AssociationReflection

Returns a new instance of AssociationReflection.



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# File 'activerecord/lib/active_record/reflection.rb', line 472

def initialize(name, scope, options, active_record)
  super
  @type = -(options[:foreign_type]&.to_s || "#{options[:as]}_type") if options[:as]
  @foreign_type = -(options[:foreign_type]&.to_s || "#{name}_type") if options[:polymorphic]
  @join_table = nil
  @foreign_key = nil
  @association_foreign_key = nil
  @association_primary_key = nil

  ensure_option_not_given_as_class!(:class_name)
end

Instance Attribute Details

#foreign_typeObject (readonly)

Returns the value of attribute foreign_type



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# File 'activerecord/lib/active_record/reflection.rb', line 469

def foreign_type
  @foreign_type
end

#parent_reflectionObject

Reflection



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# File 'activerecord/lib/active_record/reflection.rb', line 470

def parent_reflection
  @parent_reflection
end

#typeObject (readonly)

Returns the value of attribute type



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# File 'activerecord/lib/active_record/reflection.rb', line 469

def type
  @type
end

Instance Method Details

#active_record_primary_keyObject



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# File 'activerecord/lib/active_record/reflection.rb', line 513

def active_record_primary_key
  custom_primary_key = options[:primary_key]
  @active_record_primary_key ||= if custom_primary_key
    if custom_primary_key.is_a?(Array)
      custom_primary_key.map { |pk| pk.to_s.freeze }.freeze
    else
      custom_primary_key.to_s.freeze
    end
  elsif options[:query_constraints]
    active_record.query_constraints_list
  else
    primary_key(active_record).freeze
  end
end

#add_as_polymorphic_through(reflection, seed) ⇒ Object



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# File 'activerecord/lib/active_record/reflection.rb', line 639

def add_as_polymorphic_through(reflection, seed)
  seed + [PolymorphicReflection.new(self, reflection)]
end

#add_as_source(seed) ⇒ Object



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# File 'activerecord/lib/active_record/reflection.rb', line 635

def add_as_source(seed)
  seed
end

#add_as_through(seed) ⇒ Object



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# File 'activerecord/lib/active_record/reflection.rb', line 643

def add_as_through(seed)
  seed + [self]
end

#association_classObject

Raises:

  • (NotImplementedError)


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# File 'activerecord/lib/active_record/reflection.rb', line 629

def association_class; raise NotImplementedError; end

#association_foreign_keyObject



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# File 'activerecord/lib/active_record/reflection.rb', line 505

def association_foreign_key
  @association_foreign_key ||= -(options[:association_foreign_key]&.to_s || class_name.foreign_key)
end

#association_primary_key(klass = nil) ⇒ Object



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# File 'activerecord/lib/active_record/reflection.rb', line 509

def association_primary_key(klass = nil)
  primary_key(klass || self.klass)
end

#association_scope_cache(klass, owner, &block) ⇒ Object



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# File 'activerecord/lib/active_record/reflection.rb', line 484

def association_scope_cache(klass, owner, &block)
  key = self
  if polymorphic?
    key = [key, owner._read_attribute(@foreign_type)]
  end
  klass.cached_find_by_statement(key, &block)
end

#belongs_to?Boolean

Returns true if self is a belongs_to reflection.

Returns:

  • (Boolean)


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# File 'activerecord/lib/active_record/reflection.rb', line 624

def belongs_to?; false; end

#check_eager_loadable!Object



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# File 'activerecord/lib/active_record/reflection.rb', line 540

def check_eager_loadable!
  return unless scope

  unless scope.arity == 0
    raise ArgumentError, <<-MSG.squish
      The association scope '#{name}' is instance dependent (the scope
      block takes an argument). Eager loading instance dependent scopes
      is not supported.
    MSG
  end
end

#check_validity!Object



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# File 'activerecord/lib/active_record/reflection.rb', line 536

def check_validity!
  check_validity_of_inverse!
end

#clear_association_scope_cacheObject

This is for clearing cache on the reflection. Useful for tests that need to compare SQL queries on associations.



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# File 'activerecord/lib/active_record/reflection.rb', line 572

def clear_association_scope_cache # :nodoc:
  klass.initialize_find_by_cache
end

#collect_join_chainObject

A chain of reflections from this one back to the owner. For more see the explanation in ThroughReflection.



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# File 'activerecord/lib/active_record/reflection.rb', line 566

def collect_join_chain
  [self]
end

#collection?Boolean

Returns whether or not this association reflection is for a collection association. Returns true if the macro is either has_many or has_and_belongs_to_many, false otherwise.

Returns:

  • (Boolean)


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# File 'activerecord/lib/active_record/reflection.rb', line 606

def collection?
  false
end

#compute_class(name) ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/reflection.rb', line 445

def compute_class(name)
  if polymorphic?
    raise ArgumentError, "Polymorphic associations do not support computing the class."
  end

  begin
    klass = active_record.send(:compute_type, name)
  rescue NameError => error
    if error.name.match?(/(?:\A|::)#{name}\z/)
      message = "Missing model class #{name} for the #{active_record}##{self.name} association."
      message += " You can specify a different model class with the :class_name option." unless options[:class_name]
      raise NameError.new(message, name)
    else
      raise
    end
  end

  unless klass < ActiveRecord::Base
    raise ArgumentError, "The #{name} model class for the #{active_record}##{self.name} association is not an ActiveRecord::Base subclass."
  end

  klass
end

#extensionsObject



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# File 'activerecord/lib/active_record/reflection.rb', line 647

def extensions
  Array(options[:extend])
end

#foreign_keyObject



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# File 'activerecord/lib/active_record/reflection.rb', line 496

def foreign_key
  @foreign_key ||= if options[:query_constraints]
    # composite foreign keys support
    options[:query_constraints].map { |fk| fk.to_s.freeze }.freeze
  else
    -(options[:foreign_key]&.to_s || derive_foreign_key)
  end
end

#has_inverse?Boolean

Returns:

  • (Boolean)


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# File 'activerecord/lib/active_record/reflection.rb', line 584

def has_inverse?
  inverse_name
end

#has_one?Boolean

Returns true if self is a has_one reflection.

Returns:

  • (Boolean)


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# File 'activerecord/lib/active_record/reflection.rb', line 627

def has_one?; false; end

#has_scope?Boolean

Returns:

  • (Boolean)


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# File 'activerecord/lib/active_record/reflection.rb', line 580

def has_scope?
  scope
end

#join_foreign_keyObject



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# File 'activerecord/lib/active_record/reflection.rb', line 532

def join_foreign_key
  active_record_primary_key
end

#join_id_for(owner) ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/reflection.rb', line 552

def join_id_for(owner) # :nodoc:
  Array(join_foreign_key).map { |key| owner[key] }
end

#join_primary_key(klass = nil) ⇒ Object



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# File 'activerecord/lib/active_record/reflection.rb', line 528

def join_primary_key(klass = nil)
  foreign_key
end

#join_tableObject



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# File 'activerecord/lib/active_record/reflection.rb', line 492

def join_table
  @join_table ||= -(options[:join_table]&.to_s || derive_join_table)
end

#macroObject

Returns the macro type.

has_many :clients returns :has_many

Raises:

  • (NotImplementedError)


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# File 'activerecord/lib/active_record/reflection.rb', line 601

def macro; raise NotImplementedError; end

#nested?Boolean

Returns:

  • (Boolean)


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# File 'activerecord/lib/active_record/reflection.rb', line 576

def nested?
  false
end

#polymorphic?Boolean

Returns:

  • (Boolean)


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# File 'activerecord/lib/active_record/reflection.rb', line 631

def polymorphic?
  options[:polymorphic]
end

#polymorphic_inverse_of(associated_class) ⇒ Object



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# File 'activerecord/lib/active_record/reflection.rb', line 588

def polymorphic_inverse_of(associated_class)
  if has_inverse?
    if inverse_relationship = associated_class._reflect_on_association(options[:inverse_of])
      inverse_relationship
    else
      raise InverseOfAssociationNotFoundError.new(self, associated_class)
    end
  end
end

#source_reflectionObject



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# File 'activerecord/lib/active_record/reflection.rb', line 560

def source_reflection
  self
end

#through_reflectionObject



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# File 'activerecord/lib/active_record/reflection.rb', line 556

def through_reflection
  nil
end

#validate?Boolean

Returns whether or not the association should be validated as part of the parent’s validation.

Unless you explicitly disable validation with validate: false, validation will take place when:

  • you explicitly enable validation; validate: true

  • you use autosave; autosave: true

  • the association is a has_many association

Returns:

  • (Boolean)


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# File 'activerecord/lib/active_record/reflection.rb', line 619

def validate?
  !options[:validate].nil? ? options[:validate] : (options[:autosave] == true || collection?)
end