Module | ActiveRecord::Reflection::ClassMethods |
In: |
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
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
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