Class: ActiveRecord::Reflection::AssociationReflection

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

Overview

Holds all the meta-data about an association as it was specified in the Active Record class.

Instance Attribute Summary (collapse)

Attributes inherited from MacroReflection

#active_record, #macro, #name, #options, #plural_name

Instance Method Summary (collapse)

Methods inherited from MacroReflection

#==, #class_name, #sanitized_conditions

Constructor Details

- (AssociationReflection) initialize(macro, name, options, active_record)

A new instance of AssociationReflection



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# File 'activerecord/lib/active_record/reflection.rb', line 176

def initialize(macro, name, options, active_record)
  super
  @collection = macro.in?([:has_many, :has_and_belongs_to_many])
end

Instance Attribute Details

- (Object) original_build_association_called

This is a hack so that we can tell if build_association was overridden, in order to provide an appropriate deprecation if the overridden method ignored the &block. Please see Association#build_record for details.



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# File 'activerecord/lib/active_record/reflection.rb', line 184

def original_build_association_called
  @original_build_association_called
end

Instance Method Details

- (Object) active_record_primary_key 



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# File 'activerecord/lib/active_record/reflection.rb', line 231

def active_record_primary_key
  @active_record_primary_key ||= options[:primary_key] || primary_key(active_record)
end

- (Object) association_class 



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# File 'activerecord/lib/active_record/reflection.rb', line 331

def association_class
  case macro
  when :belongs_to
    if options[:polymorphic]
      Associations::BelongsToPolymorphicAssociation
    else
      Associations::BelongsToAssociation
    end
  when :has_and_belongs_to_many
    Associations::HasAndBelongsToManyAssociation
  when :has_many
    if options[:through]
      Associations::HasManyThroughAssociation
    else
      Associations::HasManyAssociation
    end
  when :has_one
    if options[:through]
      Associations::HasOneThroughAssociation
    else
      Associations::HasOneAssociation
    end
  end
end

- (Object) association_foreign_key 



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# File 'activerecord/lib/active_record/reflection.rb', line 222

def association_foreign_key
  @association_foreign_key ||= options[:association_foreign_key] || class_name.foreign_key
end

- (Object) association_primary_key(klass = nil)

klass option is necessary to support loading polymorphic associations



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# File 'activerecord/lib/active_record/reflection.rb', line 227

def association_primary_key(klass = nil)
  options[:primary_key] || primary_key(klass || self.klass)
end

- (Boolean) belongs_to?

Returns true if self is a belongs_to reflection.

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/reflection.rb', line 327

def belongs_to?
  macro == :belongs_to
end

- (Object) build_association(*options, &block)

Returns a new, unsaved instance of the associated class. options will be passed to the class's constructor.



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# File 'activerecord/lib/active_record/reflection.rb', line 188

def build_association(*options, &block)
  @original_build_association_called = true
  klass.new(*options, &block)
end

- (Object) chain

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 273

def chain
  [self]
end

- (Object) check_validity! 



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# File 'activerecord/lib/active_record/reflection.rb', line 251

def check_validity!
  check_validity_of_inverse!
end

- (Object) check_validity_of_inverse! 



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# File 'activerecord/lib/active_record/reflection.rb', line 255

def check_validity_of_inverse!
  unless options[:polymorphic]
    if has_inverse? && inverse_of.nil?
      raise InverseOfAssociationNotFoundError.new(self)
    end
  end
end

- (Boolean) collection?

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 309

def collection?
  @collection
end

- (Object) columns(tbl_name, log_msg) 



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# File 'activerecord/lib/active_record/reflection.rb', line 243

def columns(tbl_name, log_msg)
  @columns ||= klass.connection.columns(tbl_name, log_msg)
end

- (Object) conditions

An array of arrays of conditions. Each item in the outside array corresponds to a reflection in the #chain. The inside arrays are simply conditions (and each condition may itself be a hash, array, arel predicate, etc...)



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# File 'activerecord/lib/active_record/reflection.rb', line 280

def conditions
  [[options[:conditions]].compact]
end

- (Object) counter_cache_column 



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# File 'activerecord/lib/active_record/reflection.rb', line 235

def counter_cache_column
  if options[:counter_cache] == true
    "#{active_record.name.demodulize.underscore.pluralize}_count"
  elsif options[:counter_cache]
    options[:counter_cache].to_s
  end
end

- (Object) foreign_key 



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# File 'activerecord/lib/active_record/reflection.rb', line 201

def foreign_key
  @foreign_key ||= options[:foreign_key] || derive_foreign_key
end

- (Object) foreign_type 



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# File 'activerecord/lib/active_record/reflection.rb', line 210

def foreign_type
  @foreign_type ||= options[:foreign_type] || "#{name}_type"
end

- (Boolean) has_inverse?

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/reflection.rb', line 286

def has_inverse?
  @options[:inverse_of]
end

- (Object) inverse_of 



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# File 'activerecord/lib/active_record/reflection.rb', line 290

def inverse_of
  if has_inverse?
    @inverse_of ||= klass.reflect_on_association(options[:inverse_of])
  end
end

- (Object) klass

Returns the target association's class.

class Author < ActiveRecord::Base
  has_many :books
end

Author.reflect_on_association(:books).klass
# => Book

Note: Do not call klass.new or klass.create to instantiate a new association object. Use build_association or create_association instead. This allows plugins to hook into association object creation.



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# File 'activerecord/lib/active_record/reflection.rb', line 172

def klass
  @klass ||= active_record.send(:compute_type, class_name)
end

- (Object) polymorphic_inverse_of(associated_class) 



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# File 'activerecord/lib/active_record/reflection.rb', line 296

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

- (Object) primary_key_column 



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# File 'activerecord/lib/active_record/reflection.rb', line 218

def primary_key_column
  @primary_key_column ||= klass.columns.find { |c| c.name == klass.primary_key }
end

- (Object) primary_key_name 



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# File 'activerecord/lib/active_record/reflection.rb', line 205

def primary_key_name
  foreign_key
end

- (Object) quoted_table_name 



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# File 'activerecord/lib/active_record/reflection.rb', line 197

def quoted_table_name
  @quoted_table_name ||= klass.quoted_table_name
end

- (Object) reset_column_information 



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# File 'activerecord/lib/active_record/reflection.rb', line 247

def reset_column_information
  @columns = nil
end

- (Object) source_reflection 



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# File 'activerecord/lib/active_record/reflection.rb', line 267

def source_reflection
  nil
end

- (Object) table_name 



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# File 'activerecord/lib/active_record/reflection.rb', line 193

def table_name
  @table_name ||= klass.table_name
end

- (Object) through_reflection 



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# File 'activerecord/lib/active_record/reflection.rb', line 263

def through_reflection
  nil
end

- (Object) type 



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# File 'activerecord/lib/active_record/reflection.rb', line 214

def type
  @type ||= options[:as] && "#{options[:as]}_type"
end

- (Boolean) validate?

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 322

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