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 448

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]

  ensure_option_not_given_as_class!(:class_name)
end

Instance Attribute Details

#foreign_type ⇒ Object (readonly)

Returns the value of attribute foreign_type.


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

def foreign_type
  @foreign_type
end

#parent_reflection ⇒ Object

Reflection


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# File 'activerecord/lib/active_record/reflection.rb', line 446

def parent_reflection
  @parent_reflection
end

#type ⇒ Object (readonly)

Returns the value of attribute type.


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

def type
  @type
end

Instance Method Details

#active_record_primary_key ⇒ Object 


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# File 'activerecord/lib/active_record/reflection.rb', line 480

def active_record_primary_key
  @active_record_primary_key ||= -(options[:primary_key]&.to_s || primary_key(active_record))
end

#add_as_polymorphic_through(reflection, seed) ⇒ Object 


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# File 'activerecord/lib/active_record/reflection.rb', line 595

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 591

def add_as_source(seed)
  seed
end

#add_as_through(seed) ⇒ Object 


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# File 'activerecord/lib/active_record/reflection.rb', line 599

def add_as_through(seed)
  seed + [self]
end

#association_class ⇒ Object

Raises:

  • (NotImplementedError) 

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# File 'activerecord/lib/active_record/reflection.rb', line 585

def association_class; raise NotImplementedError; end

#association_foreign_key ⇒ Object 


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

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 476

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 456

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 580

def belongs_to?; false; end

#check_eager_loadable! ⇒ Object 


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

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 492

def check_validity!
  check_validity_of_inverse!
end

#clear_association_scope_cache ⇒ Object

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 528

def clear_association_scope_cache # :nodoc:
  klass.initialize_find_by_cache
end

#collect_join_chain ⇒ Object

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 522

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 562

def collection?
  false
end

#compute_class(name) ⇒ Object

:nodoc:


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# File 'activerecord/lib/active_record/reflection.rb', line 421

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

  msg = <<-MSG.squish
    Rails couldn't find a valid model for #{name} association.
    Please provide the :class_name option on the association declaration.
    If :class_name is already provided, make sure it's an ActiveRecord::Base subclass.
  MSG

  begin
    klass = active_record.send(:compute_type, name)

    unless klass < ActiveRecord::Base
      raise ArgumentError, msg
    end

    klass
  rescue NameError
    raise NameError, msg
  end
end

#extensions ⇒ Object 


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# File 'activerecord/lib/active_record/reflection.rb', line 603

def extensions
  Array(options[:extend])
end

#foreign_key ⇒ Object 


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# File 'activerecord/lib/active_record/reflection.rb', line 468

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

#has_inverse? ⇒ Boolean

Returns:

  • (Boolean) 

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

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 583

def has_one?; false; end

#has_scope? ⇒ Boolean

Returns:

  • (Boolean) 

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

def has_scope?
  scope
end

#join_foreign_key ⇒ Object 


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# File 'activerecord/lib/active_record/reflection.rb', line 488

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 508

def join_id_for(owner) # :nodoc:
  owner[join_foreign_key]
end

#join_primary_key(klass = nil) ⇒ Object 


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

def join_primary_key(klass = nil)
  foreign_key
end

#join_table ⇒ Object 


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# File 'activerecord/lib/active_record/reflection.rb', line 464

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

#macro ⇒ Object

Returns the macro type.

has_many :clients returns :has_many

Raises:

  • (NotImplementedError) 

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# File 'activerecord/lib/active_record/reflection.rb', line 557

def macro; raise NotImplementedError; end

#nested? ⇒ Boolean

Returns:

  • (Boolean) 

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

def nested?
  false
end

#polymorphic? ⇒ Boolean

Returns:

  • (Boolean) 

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# File 'activerecord/lib/active_record/reflection.rb', line 587

def polymorphic?
  options[:polymorphic]
end

#polymorphic_inverse_of(associated_class) ⇒ Object 


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# File 'activerecord/lib/active_record/reflection.rb', line 544

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_reflection ⇒ Object 


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# File 'activerecord/lib/active_record/reflection.rb', line 516

def source_reflection
  self
end

#through_reflection ⇒ Object 


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# File 'activerecord/lib/active_record/reflection.rb', line 512

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 575

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