Active Record Reflection
Reflection enables the ability to examine the associations and aggregations of Active Record classes and objects. This information, for example, can be used in a form builder that takes an Active Record object and creates input fields for all of the attributes depending on their type and displays the associations to other objects.
MacroReflection
class has info for AggregateReflection and AssociationReflection classes.
- R
Instance Public methods
reflect_on_aggregation(aggregation) Link
Returns the AggregateReflection object for the named aggregation
(use the symbol).
Account.reflect_on_aggregation(:balance) # => the balance AggregateReflection
reflect_on_all_aggregations() Link
Returns an array of AggregateReflection objects for all the aggregations in the class.
reflect_on_all_associations(macro = nil) Link
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
) 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() Link
Returns an array of AssociationReflection objects for all associations which have :autosave
enabled.
reflect_on_association(association) Link
Returns the AssociationReflection object for the association
(use the symbol).
Account.reflect_on_association(:owner) # returns the owner AssociationReflection
Invoice.reflect_on_association(:line_items).macro # returns :has_many