Module

ActiveRecord::Reflection::ClassMethods

Inheritance

Reflection allows you to interrogate Active Record classes and objects about their associations and aggregations. This information can, for example, be used in a form builder that took an Active Record object and created input fields for all of the attributes depending on their type and displayed the associations to other objects.

You can find the interface for the AggregateReflection and AssociationReflection classes in the abstract MacroReflection class.

Methods

Instance

Visibility Signature
public create_reflection (macro, name, options, active_record)
public reflect_on_aggregation (aggregation)
public reflect_on_all_aggregations ()
public reflect_on_all_associations (macro = nil)
public reflect_on_all_autosave_associations ()
public reflect_on_association (association)
public reflections ()

Instance Method Detail

create_reflection(macro, name, options, active_record)

reflect_on_aggregation(aggregation)

Returns the AggregateReflection object for the named aggregation (use the symbol). Example:

  Account.reflect_on_aggregation(:balance) # returns the balance AggregateReflection

reflect_on_all_aggregations()

Returns an array of AggregateReflection objects for all the aggregations in the class.

reflect_on_all_associations(macro = nil)

Returns an array of AssociationReflection objects for all the associations in the class. If you only want to reflect on a certain association type, pass in the symbol (:has_many, :has_one, :belongs_to) for that as the first parameter. Example:

  Account.reflect_on_all_associations             # returns an array of all associations
  Account.reflect_on_all_associations(:has_many)  # returns an array of all has_many associations

reflect_on_all_autosave_associations()

Returns an array of AssociationReflection objects for all associations which have :autosave enabled.

reflect_on_association(association)

Returns the AssociationReflection object for the named association (use the symbol). Example:

  Account.reflect_on_association(:owner) # returns the owner AssociationReflection
  Invoice.reflect_on_association(:line_items).macro  # returns :has_many

reflections()

Returns a hash containing all AssociationReflection objects for the current class Example:

  Invoice.reflections
  Account.reflections