Class: ActiveRecord::Associations::Builder::BelongsTo

Inherits:
SingularAssociation show all
Defined in:
lib/active_record/associations/builder/belongs_to.rb

Overview

:nodoc:

Instance Attribute Summary

Attributes inherited from Association

#model, #name, #options, #reflection, #scope

Instance Method Summary collapse

Methods inherited from SingularAssociation

#define_accessors, #define_constructors

Methods inherited from Association

build, #configure_dependency, #define_accessors, #define_readers, #define_writers, #initialize, #mixin, #validate_options

Constructor Details

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

Instance Method Details

#add_counter_cache_callbacks(reflection) ⇒ Object 



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# File 'lib/active_record/associations/builder/belongs_to.rb', line 22

def add_counter_cache_callbacks(reflection)
  cache_column = reflection.counter_cache_column
  foreign_key = reflection.foreign_key

  mixin.class_eval <<-CODE, __FILE__, __LINE__ + 1
    def belongs_to_counter_cache_after_create_for_#{name}
      if record = #{name}
        record.class.increment_counter(:#{cache_column}, record.id)
        @_after_create_counter_called = true
      end
    end

    def belongs_to_counter_cache_before_destroy_for_#{name}
      unless destroyed_by_association && destroyed_by_association.foreign_key.to_sym == #{foreign_key.to_sym.inspect}
        record = #{name}
        if record && !self.destroyed?
          record.class.decrement_counter(:#{cache_column}, record.id)
        end
      end
    end

    def belongs_to_counter_cache_after_update_for_#{name}
      if (@_after_create_counter_called ||= false)
        @_after_create_counter_called = false
      elsif self.#{foreign_key}_changed? && !new_record? && defined?(#{name.to_s.camelize})
        model = #{name.to_s.camelize}
        foreign_key_was = self.#{foreign_key}_was
        foreign_key = self.#{foreign_key}

        if foreign_key && model.respond_to?(:increment_counter)
          model.increment_counter(:#{cache_column}, foreign_key)
        end
        if foreign_key_was && model.respond_to?(:decrement_counter)
          model.decrement_counter(:#{cache_column}, foreign_key_was)
        end
      end
    end
  CODE

  model.after_create   "belongs_to_counter_cache_after_create_for_#{name}"
  model.before_destroy "belongs_to_counter_cache_before_destroy_for_#{name}"
  model.after_update   "belongs_to_counter_cache_after_update_for_#{name}"

  klass = reflection.class_name.safe_constantize
  klass.attr_readonly cache_column if klass && klass.respond_to?(:attr_readonly)
end

#add_touch_callbacks(reflection) ⇒ Object 



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# File 'lib/active_record/associations/builder/belongs_to.rb', line 69

def add_touch_callbacks(reflection)
  mixin.class_eval <<-CODE, __FILE__, __LINE__ + 1
    def belongs_to_touch_after_save_or_destroy_for_#{name}
      foreign_key_field = #{reflection.foreign_key.inspect}
      old_foreign_id    = changed_attributes[foreign_key_field]

      if old_foreign_id
        association = association(:#{name})
        reflection = association.reflection
        if reflection.polymorphic?
          klass = send("#{reflection.foreign_type}_was").constantize
        else
          klass = association.klass
        end
        old_record = klass.find_by(klass.primary_key => old_foreign_id)

        if old_record
          old_record.touch #{options[:touch].inspect if options[:touch] != true}
        end
      end

      record = #{name}
      if record && record.persisted?
        record.touch #{options[:touch].inspect if options[:touch] != true}
      end
    end
  CODE

  model.after_save    "belongs_to_touch_after_save_or_destroy_for_#{name}"
  model.after_touch   "belongs_to_touch_after_save_or_destroy_for_#{name}"
  model.after_destroy "belongs_to_touch_after_save_or_destroy_for_#{name}"
end

#build ⇒ Object 



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# File 'lib/active_record/associations/builder/belongs_to.rb', line 15

def build
  reflection = super
  add_counter_cache_callbacks(reflection) if options[:counter_cache]
  add_touch_callbacks(reflection)         if options[:touch]
  reflection
end

#constructable? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/associations/builder/belongs_to.rb', line 11

def constructable?
  !options[:polymorphic]
end

#macro ⇒ Object 



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# File 'lib/active_record/associations/builder/belongs_to.rb', line 3

def macro
  :belongs_to
end

#valid_dependent_options ⇒ Object 



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# File 'lib/active_record/associations/builder/belongs_to.rb', line 102

def valid_dependent_options
  [:destroy, :delete]
end

#valid_options ⇒ Object 



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# File 'lib/active_record/associations/builder/belongs_to.rb', line 7

def valid_options
  super + [:foreign_type, :polymorphic, :touch, :counter_cache]
end