Module | ActiveRecord::Reflection::ClassMethods |
In: |
vendor/rails/activerecord/lib/active_record/reflection.rb
|
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.
Returns the AggregateReflection object for the named aggregation (use the symbol). Example:
Account.reflect_on_aggregation(:balance) # returns the balance AggregateReflection
# File vendor/rails/activerecord/lib/active_record/reflection.rb, line 50 50: def reflect_on_aggregation(aggregation) 51: reflect_on_all_aggregations.find { |reflection| reflection.name == aggregation } unless reflect_on_all_aggregations.nil? 52: end
Returns an array of AggregateReflection objects for all the aggregations in the class.
# File vendor/rails/activerecord/lib/active_record/reflection.rb, line 44 44: def reflect_on_all_aggregations 45: read_inheritable_attribute(:aggregations) or write_inheritable_attribute(:aggregations, []) 46: end
Returns an array of AssociationReflection objects for all the aggregations in the class.
# File vendor/rails/activerecord/lib/active_record/reflection.rb, line 55 55: def reflect_on_all_associations 56: read_inheritable_attribute(:associations) or write_inheritable_attribute(:associations, []) 57: end
Returns the AssociationReflection object for the named aggregation (use the symbol). Example:
Account.reflect_on_association(:owner) # returns the owner AssociationReflection
# File vendor/rails/activerecord/lib/active_record/reflection.rb, line 61 61: def reflect_on_association(association) 62: reflect_on_all_associations.find { |reflection| reflection.name == association } 63: end