Module: ActiveRecord::Reflection::ClassMethods
- Defined in:
- lib/active_record/reflection.rb
Overview
Reflection enables interrogating of Active Record classes and objects about their associations and aggregations. This information can, for example, 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.
Instance Method Summary collapse
-
#_reflect_on_association(association) ⇒ Object
@api private.
-
#clear_reflections_cache ⇒ Object
:nodoc:.
-
#reflect_on_aggregation(aggregation) ⇒ Object
Returns the AggregateReflection object for the named
aggregation
(use the symbol). -
#reflect_on_all_aggregations ⇒ Object
Returns an array of AggregateReflection objects for all the aggregations in the class.
-
#reflect_on_all_associations(macro = nil) ⇒ Object
Returns an array of AssociationReflection objects for all the associations in the class.
-
#reflect_on_all_autosave_associations ⇒ Object
Returns an array of AssociationReflection objects for all associations which have
:autosave
enabled. -
#reflect_on_association(association) ⇒ Object
Returns the AssociationReflection object for the
association
(use the symbol). -
#reflections ⇒ Object
Returns a Hash of name of the reflection as the key and a AssociationReflection as the value.
Instance Method Details
#_reflect_on_association(association) ⇒ Object
@api private
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# File 'lib/active_record/reflection.rb', line 115 def _reflect_on_association(association) #:nodoc: _reflections[association.to_s] end |
#clear_reflections_cache ⇒ Object
:nodoc:
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# File 'lib/active_record/reflection.rb', line 126 def clear_reflections_cache #:nodoc: @__reflections = nil end |
#reflect_on_aggregation(aggregation) ⇒ Object
Returns the AggregateReflection object for the named aggregation
(use the symbol).
Account.reflect_on_aggregation(:balance) # => the balance AggregateReflection
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# File 'lib/active_record/reflection.rb', line 61 def reflect_on_aggregation(aggregation) aggregate_reflections[aggregation.to_s] end |
#reflect_on_all_aggregations ⇒ Object
Returns an array of AggregateReflection objects for all the aggregations in the class.
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# File 'lib/active_record/reflection.rb', line 53 def reflect_on_all_aggregations aggregate_reflections.values end |
#reflect_on_all_associations(macro = nil) ⇒ Object
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
@api public
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# File 'lib/active_record/reflection.rb', line 99 def reflect_on_all_associations(macro = nil) association_reflections = reflections.values macro ? association_reflections.select { |reflection| reflection.macro == macro } : association_reflections end |
#reflect_on_all_autosave_associations ⇒ Object
Returns an array of AssociationReflection objects for all associations which have :autosave
enabled.
@api public
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# File 'lib/active_record/reflection.rb', line 122 def reflect_on_all_autosave_associations reflections.values.select { |reflection| reflection.[:autosave] } end |
#reflect_on_association(association) ⇒ Object
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
@api public
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# File 'lib/active_record/reflection.rb', line 110 def reflect_on_association(association) reflections[association.to_s] end |
#reflections ⇒ Object
Returns a Hash of name of the reflection as the key and a AssociationReflection as the value.
Account.reflections # => {"balance" => AggregateReflection}
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# File 'lib/active_record/reflection.rb', line 70 def reflections @__reflections ||= begin ref = {} _reflections.each do |name, reflection| parent_name, parent_reflection = reflection.parent_reflection if parent_name ref[parent_name] = parent_reflection else ref[name] = reflection end end ref end end |