Class: ActiveRecord::Associations::BelongsToAssociation

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

attr_reader :foreign_key, :foreign_type

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 165

def foreign_key_present?
  foreign_key.all? { |fk| owner.read_attribute(fk) }
end

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

attr_reader :foreign_key, :foreign_type

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 139

def require_counter_update?
  reflection.counter_cache_column && owner.persisted?
end

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 100

def saved_change_to_target?
  foreign_key.any? { |fk| owner.saved_change_to_attribute?(fk) }
end

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 92

def target_changed?
  foreign_key.any? { |fk| owner.attribute_changed?(fk) } || (!foreign_key_present? && target&.new_record?)
end

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 96

def target_previously_changed?
  foreign_key.any? { |fk| owner.attribute_previously_changed?(fk) }
end

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 64

def updated?
  @updated
end

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 76

def decrement_counters_before_last_save
  if reflection.polymorphic?
    model_type_was = owner.attribute_before_last_save(foreign_type)
    model_was = owner.class.polymorphic_class_for(model_type_was) if model_type_was
  else
    model_was = klass
  end

  values = foreign_key.map { |fk| owner.attribute_before_last_save(fk) }
  foreign_key_was = foreign_key.composite? ? (values if values.all?) : values.first

  if foreign_key_was && model_was < ActiveRecord::Base
    update_counters_via_scope(model_was, foreign_key_was, -1)
  end
end

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 55

def default(&block)
  writer(owner.instance_exec(&block)) if reader.nil?
end

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 21

def handle_dependency
  return unless load_target

  case options[:dependent]
  when :destroy
    raise ActiveRecord::Rollback unless target.destroy
  when :destroy_async
    primary_key_column = reflection.active_record_primary_key
    ids = foreign_key.map { |col| owner.public_send(col) }

    association_class = if reflection.polymorphic?
      owner.public_send(foreign_type)
    else
      reflection.klass
    end

    enqueue_destroy_association(
      owner_model_name: owner.class.to_s,
      owner_id: owner.id,
      association_class: association_class.to_s,
      association_ids: foreign_key.composite? ? [ids] : ids,
      association_primary_key_column: primary_key_column,
      ensuring_owner_was_method: options.fetch(:ensuring_owner_was, nil)
    )
  else
    target.public_send(options[:dependent])
  end
end

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 72

def increment_counters
  update_counters(1)
end

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 50

def inversed_from(record)
  replace_keys(record)
  super
end

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 169

def invertible_for?(record)
  inverse = inverse_reflection_for(record)
  inverse && (inverse.has_one? || inverse.klass.has_many_inversing)
end

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 161

def primary_key(klass)
  reflection.association_primary_key(klass)
end

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 105

def replace(record)
  if record
    raise_on_type_mismatch!(record)
    set_inverse_instance(record)
    @updated = true
  elsif target
    remove_inverse_instance(target)
  end

  replace_keys(record, force: true)

  self.target = record
end

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 143

def replace_keys(record, force: false)
  target_key_values = record ? ActiveRecord::Key.for(primary_key(record.class)).map { |col| record.read_attribute(col) } : []
  owner_key_values = foreign_key.map { |fk| owner.read_attribute(fk) }

  return if !force && owner_key_values == target_key_values

  owner_pk = ActiveRecord::Key.for(owner.class.primary_key)

  # Preserve shared primary key columns only if another foreign key
  # column can be cleared to disassociate the record.
  preserve_owner_pk = record.nil? && foreign_key.any? { |key| !owner_pk.include?(key) }

  foreign_key.each_with_index do |key, index|
    next if preserve_owner_pk && owner_pk.include?(key)
    owner.write_attribute(key, target_key_values[index])
  end
end

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 59

def reset
  super
  @updated = false
end

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 174

def stale_state
  values = foreign_key.map do |fk|
    owner.read_attribute(fk) { |n| owner.send(:missing_attribute, n, caller) }
  end
  foreign_key.composite? ? (values if values.any?) : values.first
end

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 119

def update_counters(by)
  if require_counter_update? && foreign_key_present?
    if target && !stale_target?
      target.increment!(reflection.counter_cache_column, by, touch: reflection.options[:touch])
    else
      update_counters_via_scope(klass, foreign_key.value_of(owner), by)
    end
  end
end

# File 'activerecord/lib/active_record/associations/belongs_to_association.rb', line 129

def update_counters_via_scope(klass, values, by)
  primary_key = ActiveRecord::Key.for(primary_key(klass))
  scope = klass.all_queries_scope.where!(primary_key.where_hash(values))
  scope.update_counters(reflection.counter_cache_column => by, touch: reflection.options[:touch])
end