mirror of
https://github.com/rails/rails.git
synced 2022-11-09 12:12:34 -05:00
ac027338e4
- we are ending sentences properly
- fixing of space issues
- fixed continuity issues in some sentences.
Reverts 8fc97d198e .
This change reverts making sure we add '.' at end of deprecation sentences.
This is to keep sentences within Rails itself consistent and with a '.' at the end.
1060 lines
33 KiB
Ruby
1060 lines
33 KiB
Ruby
require 'thread'
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require 'active_support/core_ext/string/filters'
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module ActiveRecord
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# = Active Record Reflection
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module Reflection # :nodoc:
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extend ActiveSupport::Concern
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included do
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class_attribute :_reflections, instance_writer: false
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class_attribute :aggregate_reflections, instance_writer: false
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self._reflections = {}
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self.aggregate_reflections = {}
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end
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def self.create(macro, name, scope, options, ar)
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klass = case macro
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when :composed_of
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AggregateReflection
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when :has_many
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HasManyReflection
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when :has_one
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HasOneReflection
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when :belongs_to
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BelongsToReflection
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else
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raise "Unsupported Macro: #{macro}"
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end
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reflection = klass.new(name, scope, options, ar)
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options[:through] ? ThroughReflection.new(reflection) : reflection
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end
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def self.add_reflection(ar, name, reflection)
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ar.clear_reflections_cache
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ar._reflections = ar._reflections.merge(name.to_s => reflection)
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end
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def self.add_aggregate_reflection(ar, name, reflection)
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ar.aggregate_reflections = ar.aggregate_reflections.merge(name.to_s => reflection)
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end
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# \Reflection enables the ability to examine the associations and aggregations of
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# Active Record classes and objects. This information, for example,
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# can be used in a form builder that takes an Active Record object
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# and creates input fields for all of the attributes depending on their type
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# and displays the associations to other objects.
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#
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# MacroReflection class has info for AggregateReflection and AssociationReflection
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# classes.
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module ClassMethods
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# Returns an array of AggregateReflection objects for all the aggregations in the class.
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def reflect_on_all_aggregations
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aggregate_reflections.values
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end
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# Returns the AggregateReflection object for the named +aggregation+ (use the symbol).
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#
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# Account.reflect_on_aggregation(:balance) # => the balance AggregateReflection
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#
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def reflect_on_aggregation(aggregation)
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aggregate_reflections[aggregation.to_s]
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end
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# Returns a Hash of name of the reflection as the key and an AssociationReflection as the value.
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#
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# Account.reflections # => {"balance" => AggregateReflection}
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#
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def reflections
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@__reflections ||= begin
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ref = {}
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_reflections.each do |name, reflection|
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parent_reflection = reflection.parent_reflection
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if parent_reflection
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parent_name = parent_reflection.name
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ref[parent_name.to_s] = parent_reflection
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else
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ref[name] = reflection
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end
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end
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ref
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end
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end
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# Returns an array of AssociationReflection objects for all the
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# associations in the class. If you only want to reflect on a certain
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# association type, pass in the symbol (<tt>:has_many</tt>, <tt>:has_one</tt>,
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# <tt>:belongs_to</tt>) as the first parameter.
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#
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# Example:
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#
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# Account.reflect_on_all_associations # returns an array of all associations
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# Account.reflect_on_all_associations(:has_many) # returns an array of all has_many associations
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#
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def reflect_on_all_associations(macro = nil)
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association_reflections = reflections.values
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association_reflections.select! { |reflection| reflection.macro == macro } if macro
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association_reflections
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end
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# Returns the AssociationReflection object for the +association+ (use the symbol).
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#
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# Account.reflect_on_association(:owner) # returns the owner AssociationReflection
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# Invoice.reflect_on_association(:line_items).macro # returns :has_many
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#
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def reflect_on_association(association)
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reflections[association.to_s]
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end
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def _reflect_on_association(association) #:nodoc:
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_reflections[association.to_s]
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end
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# Returns an array of AssociationReflection objects for all associations which have <tt>:autosave</tt> enabled.
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def reflect_on_all_autosave_associations
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reflections.values.select { |reflection| reflection.options[:autosave] }
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end
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def clear_reflections_cache # :nodoc:
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@__reflections = nil
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end
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end
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# Holds all the methods that are shared between MacroReflection and ThroughReflection.
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#
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# AbstractReflection
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# MacroReflection
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# AggregateReflection
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# AssociationReflection
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# HasManyReflection
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# HasOneReflection
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# BelongsToReflection
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# HasAndBelongsToManyReflection
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# ThroughReflection
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# PolymorphicReflection
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# RuntimeReflection
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class AbstractReflection # :nodoc:
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def through_reflection?
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false
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end
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def table_name
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klass.table_name
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end
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# Returns a new, unsaved instance of the associated class. +attributes+ will
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# be passed to the class's constructor.
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def build_association(attributes, &block)
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klass.new(attributes, &block)
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end
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def quoted_table_name
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klass.quoted_table_name
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end
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def primary_key_type
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klass.type_for_attribute(klass.primary_key)
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end
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# Returns the class name for the macro.
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#
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# <tt>composed_of :balance, class_name: 'Money'</tt> returns <tt>'Money'</tt>
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# <tt>has_many :clients</tt> returns <tt>'Client'</tt>
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def class_name
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@class_name ||= (options[:class_name] || derive_class_name).to_s
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end
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JoinKeys = Struct.new(:key, :foreign_key) # :nodoc:
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def join_keys(association_klass)
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JoinKeys.new(foreign_key, active_record_primary_key)
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end
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def constraints
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scope_chain.flatten
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end
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def counter_cache_column
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if belongs_to?
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if options[:counter_cache] == true
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"#{active_record.name.demodulize.underscore.pluralize}_count"
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elsif options[:counter_cache]
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options[:counter_cache].to_s
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end
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else
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options[:counter_cache] ? options[:counter_cache].to_s : "#{name}_count"
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end
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end
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def inverse_of
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return unless inverse_name
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@inverse_of ||= klass._reflect_on_association inverse_name
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end
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def check_validity_of_inverse!
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unless polymorphic?
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if has_inverse? && inverse_of.nil?
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raise InverseOfAssociationNotFoundError.new(self)
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end
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end
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end
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# This shit is nasty. We need to avoid the following situation:
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#
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# * An associated record is deleted via record.destroy
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# * Hence the callbacks run, and they find a belongs_to on the record with a
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# :counter_cache options which points back at our owner. So they update the
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# counter cache.
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# * In which case, we must make sure to *not* update the counter cache, or else
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# it will be decremented twice.
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#
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# Hence this method.
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def inverse_which_updates_counter_cache
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return @inverse_which_updates_counter_cache if defined?(@inverse_which_updates_counter_cache)
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@inverse_which_updates_counter_cache = klass.reflect_on_all_associations(:belongs_to).find do |inverse|
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inverse.counter_cache_column == counter_cache_column
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end
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end
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alias inverse_updates_counter_cache? inverse_which_updates_counter_cache
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def inverse_updates_counter_in_memory?
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inverse_of && inverse_which_updates_counter_cache == inverse_of
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end
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# Returns whether a counter cache should be used for this association.
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#
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# The counter_cache option must be given on either the owner or inverse
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# association, and the column must be present on the owner.
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def has_cached_counter?
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options[:counter_cache] ||
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inverse_which_updates_counter_cache && inverse_which_updates_counter_cache.options[:counter_cache] &&
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!!active_record.columns_hash[counter_cache_column]
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end
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def counter_must_be_updated_by_has_many?
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!inverse_updates_counter_in_memory? && has_cached_counter?
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end
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def alias_candidate(name)
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"#{plural_name}_#{name}"
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end
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def chain
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collect_join_chain
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end
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end
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# Base class for AggregateReflection and AssociationReflection. Objects of
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# AggregateReflection and AssociationReflection are returned by the Reflection::ClassMethods.
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class MacroReflection < AbstractReflection
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# Returns the name of the macro.
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#
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# <tt>composed_of :balance, class_name: 'Money'</tt> returns <tt>:balance</tt>
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# <tt>has_many :clients</tt> returns <tt>:clients</tt>
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attr_reader :name
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attr_reader :scope
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# Returns the hash of options used for the macro.
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#
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# <tt>composed_of :balance, class_name: 'Money'</tt> returns <tt>{ class_name: "Money" }</tt>
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# <tt>has_many :clients</tt> returns <tt>{}</tt>
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attr_reader :options
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attr_reader :active_record
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attr_reader :plural_name # :nodoc:
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def initialize(name, scope, options, active_record)
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@name = name
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@scope = scope
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@options = options
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@active_record = active_record
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@klass = options[:anonymous_class]
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@plural_name = active_record.pluralize_table_names ?
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name.to_s.pluralize : name.to_s
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end
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def autosave=(autosave)
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@automatic_inverse_of = false
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@options[:autosave] = autosave
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parent_reflection = self.parent_reflection
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if parent_reflection
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parent_reflection.autosave = autosave
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end
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end
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# Returns the class for the macro.
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#
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# <tt>composed_of :balance, class_name: 'Money'</tt> returns the Money class
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# <tt>has_many :clients</tt> returns the Client class
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def klass
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@klass ||= compute_class(class_name)
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end
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def compute_class(name)
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name.constantize
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end
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# Returns +true+ if +self+ and +other_aggregation+ have the same +name+ attribute, +active_record+ attribute,
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# and +other_aggregation+ has an options hash assigned to it.
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def ==(other_aggregation)
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super ||
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other_aggregation.kind_of?(self.class) &&
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name == other_aggregation.name &&
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!other_aggregation.options.nil? &&
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active_record == other_aggregation.active_record
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end
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private
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def derive_class_name
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name.to_s.camelize
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end
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end
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# Holds all the meta-data about an aggregation as it was specified in the
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# Active Record class.
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class AggregateReflection < MacroReflection #:nodoc:
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def mapping
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mapping = options[:mapping] || [name, name]
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mapping.first.is_a?(Array) ? mapping : [mapping]
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end
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end
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# Holds all the meta-data about an association as it was specified in the
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# Active Record class.
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class AssociationReflection < MacroReflection #:nodoc:
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# Returns the target association's class.
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#
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# class Author < ActiveRecord::Base
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# has_many :books
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# end
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#
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# Author.reflect_on_association(:books).klass
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# # => Book
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#
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# <b>Note:</b> Do not call +klass.new+ or +klass.create+ to instantiate
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# a new association object. Use +build_association+ or +create_association+
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# instead. This allows plugins to hook into association object creation.
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def klass
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@klass ||= compute_class(class_name)
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end
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def compute_class(name)
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active_record.send(:compute_type, name)
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end
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attr_reader :type, :foreign_type
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attr_accessor :parent_reflection # Reflection
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def initialize(name, scope, options, active_record)
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super
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@automatic_inverse_of = nil
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@type = options[:as] && (options[:foreign_type] || "#{options[:as]}_type")
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@foreign_type = options[:foreign_type] || "#{name}_type"
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@constructable = calculate_constructable(macro, options)
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@association_scope_cache = {}
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@scope_lock = Mutex.new
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end
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def association_scope_cache(conn, owner)
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key = conn.prepared_statements
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if polymorphic?
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key = [key, owner._read_attribute(@foreign_type)]
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end
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@association_scope_cache[key] ||= @scope_lock.synchronize {
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@association_scope_cache[key] ||= yield
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}
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end
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def constructable? # :nodoc:
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@constructable
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end
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def join_table
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@join_table ||= options[:join_table] || derive_join_table
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end
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def foreign_key
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@foreign_key ||= options[:foreign_key] || derive_foreign_key.freeze
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end
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def association_foreign_key
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@association_foreign_key ||= options[:association_foreign_key] || class_name.foreign_key
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end
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# klass option is necessary to support loading polymorphic associations
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def association_primary_key(klass = nil)
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options[:primary_key] || primary_key(klass || self.klass)
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end
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def active_record_primary_key
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@active_record_primary_key ||= options[:primary_key] || primary_key(active_record)
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end
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def check_validity!
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check_validity_of_inverse!
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end
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def check_preloadable!
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return unless scope
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if scope.arity > 0
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raise ArgumentError, <<-MSG.squish
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The association scope '#{name}' is instance dependent (the scope
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block takes an argument). Preloading instance dependent scopes is
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not supported.
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MSG
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end
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end
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alias :check_eager_loadable! :check_preloadable!
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def join_id_for(owner) # :nodoc:
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owner[active_record_primary_key]
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end
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def through_reflection
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nil
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end
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def source_reflection
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self
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end
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# A chain of reflections from this one back to the owner. For more see the explanation in
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# ThroughReflection.
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def collect_join_chain
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[self]
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end
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# This is for clearing cache on the reflection. Useful for tests that need to compare
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# SQL queries on associations.
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def clear_association_scope_cache # :nodoc:
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@association_scope_cache.clear
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end
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def nested?
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false
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end
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# An array of arrays of scopes. Each item in the outside array corresponds to a reflection
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# in the #chain.
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def scope_chain
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scope ? [[scope]] : [[]]
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end
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def has_scope?
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scope
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end
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def has_inverse?
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inverse_name
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end
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def polymorphic_inverse_of(associated_class)
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if has_inverse?
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if inverse_relationship = associated_class._reflect_on_association(options[:inverse_of])
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inverse_relationship
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else
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raise InverseOfAssociationNotFoundError.new(self, associated_class)
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end
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end
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end
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# Returns the macro type.
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#
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# <tt>has_many :clients</tt> returns <tt>:has_many</tt>
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def macro; raise NotImplementedError; end
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# Returns whether or not this association reflection is for a collection
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# association. Returns +true+ if the +macro+ is either +has_many+ or
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# +has_and_belongs_to_many+, +false+ otherwise.
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def collection?
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false
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end
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# Returns whether or not the association should be validated as part of
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# the parent's validation.
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#
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# Unless you explicitly disable validation with
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# <tt>validate: false</tt>, validation will take place when:
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#
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# * you explicitly enable validation; <tt>validate: true</tt>
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# * you use autosave; <tt>autosave: true</tt>
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# * the association is a +has_many+ association
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def validate?
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!options[:validate].nil? ? options[:validate] : (options[:autosave] == true || collection?)
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end
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# Returns +true+ if +self+ is a +belongs_to+ reflection.
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def belongs_to?; false; end
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# Returns +true+ if +self+ is a +has_one+ reflection.
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def has_one?; false; end
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def association_class; raise NotImplementedError; end
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def polymorphic?
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options[:polymorphic]
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end
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VALID_AUTOMATIC_INVERSE_MACROS = [:has_many, :has_one, :belongs_to]
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INVALID_AUTOMATIC_INVERSE_OPTIONS = [:conditions, :through, :polymorphic, :foreign_key]
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def add_as_source(seed)
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seed
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end
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def add_as_polymorphic_through(reflection, seed)
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seed + [PolymorphicReflection.new(self, reflection)]
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end
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def add_as_through(seed)
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seed + [self]
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end
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protected
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def actual_source_reflection # FIXME: this is a horrible name
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self
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end
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private
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def calculate_constructable(macro, options)
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true
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end
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# Attempts to find the inverse association name automatically.
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# If it cannot find a suitable inverse association name, it returns
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# nil.
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def inverse_name
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options.fetch(:inverse_of) do
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if @automatic_inverse_of == false
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nil
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else
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@automatic_inverse_of ||= automatic_inverse_of
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end
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end
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end
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# returns either false or the inverse association name that it finds.
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def automatic_inverse_of
|
|
if can_find_inverse_of_automatically?(self)
|
|
inverse_name = ActiveSupport::Inflector.underscore(options[:as] || active_record.name.demodulize).to_sym
|
|
|
|
begin
|
|
reflection = klass._reflect_on_association(inverse_name)
|
|
rescue NameError
|
|
# Give up: we couldn't compute the klass type so we won't be able
|
|
# to find any associations either.
|
|
reflection = false
|
|
end
|
|
|
|
if valid_inverse_reflection?(reflection)
|
|
return inverse_name
|
|
end
|
|
end
|
|
|
|
false
|
|
end
|
|
|
|
# Checks if the inverse reflection that is returned from the
|
|
# +automatic_inverse_of+ method is a valid reflection. We must
|
|
# make sure that the reflection's active_record name matches up
|
|
# with the current reflection's klass name.
|
|
#
|
|
# Note: klass will always be valid because when there's a NameError
|
|
# from calling +klass+, +reflection+ will already be set to false.
|
|
def valid_inverse_reflection?(reflection)
|
|
reflection &&
|
|
klass.name == reflection.active_record.name &&
|
|
can_find_inverse_of_automatically?(reflection)
|
|
end
|
|
|
|
# Checks to see if the reflection doesn't have any options that prevent
|
|
# us from being able to guess the inverse automatically. First, the
|
|
# <tt>inverse_of</tt> option cannot be set to false. Second, we must
|
|
# have <tt>has_many</tt>, <tt>has_one</tt>, <tt>belongs_to</tt> associations.
|
|
# Third, we must not have options such as <tt>:polymorphic</tt> or
|
|
# <tt>:foreign_key</tt> which prevent us from correctly guessing the
|
|
# inverse association.
|
|
#
|
|
# Anything with a scope can additionally ruin our attempt at finding an
|
|
# inverse, so we exclude reflections with scopes.
|
|
def can_find_inverse_of_automatically?(reflection)
|
|
reflection.options[:inverse_of] != false &&
|
|
VALID_AUTOMATIC_INVERSE_MACROS.include?(reflection.macro) &&
|
|
!INVALID_AUTOMATIC_INVERSE_OPTIONS.any? { |opt| reflection.options[opt] } &&
|
|
!reflection.scope
|
|
end
|
|
|
|
def derive_class_name
|
|
class_name = name.to_s
|
|
class_name = class_name.singularize if collection?
|
|
class_name.camelize
|
|
end
|
|
|
|
def derive_foreign_key
|
|
if belongs_to?
|
|
"#{name}_id"
|
|
elsif options[:as]
|
|
"#{options[:as]}_id"
|
|
else
|
|
active_record.name.foreign_key
|
|
end
|
|
end
|
|
|
|
def derive_join_table
|
|
ModelSchema.derive_join_table_name active_record.table_name, klass.table_name
|
|
end
|
|
|
|
def primary_key(klass)
|
|
klass.primary_key || raise(UnknownPrimaryKey.new(klass))
|
|
end
|
|
end
|
|
|
|
class HasManyReflection < AssociationReflection # :nodoc:
|
|
def macro; :has_many; end
|
|
|
|
def collection?; true; end
|
|
|
|
def association_class
|
|
if options[:through]
|
|
Associations::HasManyThroughAssociation
|
|
else
|
|
Associations::HasManyAssociation
|
|
end
|
|
end
|
|
end
|
|
|
|
class HasOneReflection < AssociationReflection # :nodoc:
|
|
def macro; :has_one; end
|
|
|
|
def has_one?; true; end
|
|
|
|
def association_class
|
|
if options[:through]
|
|
Associations::HasOneThroughAssociation
|
|
else
|
|
Associations::HasOneAssociation
|
|
end
|
|
end
|
|
|
|
private
|
|
|
|
def calculate_constructable(macro, options)
|
|
!options[:through]
|
|
end
|
|
end
|
|
|
|
class BelongsToReflection < AssociationReflection # :nodoc:
|
|
def macro; :belongs_to; end
|
|
|
|
def belongs_to?; true; end
|
|
|
|
def association_class
|
|
if polymorphic?
|
|
Associations::BelongsToPolymorphicAssociation
|
|
else
|
|
Associations::BelongsToAssociation
|
|
end
|
|
end
|
|
|
|
def join_keys(association_klass)
|
|
key = polymorphic? ? association_primary_key(association_klass) : association_primary_key
|
|
JoinKeys.new(key, foreign_key)
|
|
end
|
|
|
|
def join_id_for(owner) # :nodoc:
|
|
owner[foreign_key]
|
|
end
|
|
|
|
private
|
|
|
|
def calculate_constructable(macro, options)
|
|
!polymorphic?
|
|
end
|
|
end
|
|
|
|
class HasAndBelongsToManyReflection < AssociationReflection # :nodoc:
|
|
def initialize(name, scope, options, active_record)
|
|
super
|
|
end
|
|
|
|
def macro; :has_and_belongs_to_many; end
|
|
|
|
def collection?
|
|
true
|
|
end
|
|
end
|
|
|
|
# Holds all the meta-data about a :through association as it was specified
|
|
# in the Active Record class.
|
|
class ThroughReflection < AbstractReflection #:nodoc:
|
|
attr_reader :delegate_reflection
|
|
delegate :foreign_key, :foreign_type, :association_foreign_key,
|
|
:active_record_primary_key, :type, :to => :source_reflection
|
|
|
|
def initialize(delegate_reflection)
|
|
@delegate_reflection = delegate_reflection
|
|
@klass = delegate_reflection.options[:anonymous_class]
|
|
@source_reflection_name = delegate_reflection.options[:source]
|
|
end
|
|
|
|
def through_reflection?
|
|
true
|
|
end
|
|
|
|
def klass
|
|
@klass ||= delegate_reflection.compute_class(class_name)
|
|
end
|
|
|
|
# Returns the source of the through reflection. It checks both a singularized
|
|
# and pluralized form for <tt>:belongs_to</tt> or <tt>:has_many</tt>.
|
|
#
|
|
# class Post < ActiveRecord::Base
|
|
# has_many :taggings
|
|
# has_many :tags, through: :taggings
|
|
# end
|
|
#
|
|
# class Tagging < ActiveRecord::Base
|
|
# belongs_to :post
|
|
# belongs_to :tag
|
|
# end
|
|
#
|
|
# tags_reflection = Post.reflect_on_association(:tags)
|
|
# tags_reflection.source_reflection
|
|
# # => <ActiveRecord::Reflection::BelongsToReflection: @name=:tag, @active_record=Tagging, @plural_name="tags">
|
|
#
|
|
def source_reflection
|
|
through_reflection.klass._reflect_on_association(source_reflection_name)
|
|
end
|
|
|
|
# Returns the AssociationReflection object specified in the <tt>:through</tt> option
|
|
# of a HasManyThrough or HasOneThrough association.
|
|
#
|
|
# class Post < ActiveRecord::Base
|
|
# has_many :taggings
|
|
# has_many :tags, through: :taggings
|
|
# end
|
|
#
|
|
# tags_reflection = Post.reflect_on_association(:tags)
|
|
# tags_reflection.through_reflection
|
|
# # => <ActiveRecord::Reflection::HasManyReflection: @name=:taggings, @active_record=Post, @plural_name="taggings">
|
|
#
|
|
def through_reflection
|
|
active_record._reflect_on_association(options[:through])
|
|
end
|
|
|
|
# Returns an array of reflections which are involved in this association. Each item in the
|
|
# array corresponds to a table which will be part of the query for this association.
|
|
#
|
|
# The chain is built by recursively calling #chain on the source reflection and the through
|
|
# reflection. The base case for the recursion is a normal association, which just returns
|
|
# [self] as its #chain.
|
|
#
|
|
# class Post < ActiveRecord::Base
|
|
# has_many :taggings
|
|
# has_many :tags, through: :taggings
|
|
# end
|
|
#
|
|
# tags_reflection = Post.reflect_on_association(:tags)
|
|
# tags_reflection.chain
|
|
# # => [<ActiveRecord::Reflection::ThroughReflection: @delegate_reflection=#<ActiveRecord::Reflection::HasManyReflection: @name=:tags...>,
|
|
# <ActiveRecord::Reflection::HasManyReflection: @name=:taggings, @options={}, @active_record=Post>]
|
|
#
|
|
def collect_join_chain
|
|
collect_join_reflections [self]
|
|
end
|
|
|
|
# This is for clearing cache on the reflection. Useful for tests that need to compare
|
|
# SQL queries on associations.
|
|
def clear_association_scope_cache # :nodoc:
|
|
delegate_reflection.clear_association_scope_cache
|
|
source_reflection.clear_association_scope_cache
|
|
through_reflection.clear_association_scope_cache
|
|
end
|
|
|
|
# Consider the following example:
|
|
#
|
|
# class Person
|
|
# has_many :articles
|
|
# has_many :comment_tags, through: :articles
|
|
# end
|
|
#
|
|
# class Article
|
|
# has_many :comments
|
|
# has_many :comment_tags, through: :comments, source: :tags
|
|
# end
|
|
#
|
|
# class Comment
|
|
# has_many :tags
|
|
# end
|
|
#
|
|
# There may be scopes on Person.comment_tags, Article.comment_tags and/or Comment.tags,
|
|
# but only Comment.tags will be represented in the #chain. So this method creates an array
|
|
# of scopes corresponding to the chain.
|
|
def scope_chain
|
|
@scope_chain ||= begin
|
|
scope_chain = source_reflection.scope_chain.map(&:dup)
|
|
|
|
# Add to it the scope from this reflection (if any)
|
|
scope_chain.first << scope if scope
|
|
|
|
through_scope_chain = through_reflection.scope_chain.map(&:dup)
|
|
|
|
if options[:source_type]
|
|
type = foreign_type
|
|
source_type = options[:source_type]
|
|
through_scope_chain.first << lambda { |object|
|
|
where(type => source_type)
|
|
}
|
|
end
|
|
|
|
# Recursively fill out the rest of the array from the through reflection
|
|
scope_chain + through_scope_chain
|
|
end
|
|
end
|
|
|
|
def has_scope?
|
|
scope || options[:source_type] ||
|
|
source_reflection.has_scope? ||
|
|
through_reflection.has_scope?
|
|
end
|
|
|
|
def join_keys(association_klass)
|
|
source_reflection.join_keys(association_klass)
|
|
end
|
|
|
|
# A through association is nested if there would be more than one join table
|
|
def nested?
|
|
source_reflection.through_reflection? || through_reflection.through_reflection?
|
|
end
|
|
|
|
# We want to use the klass from this reflection, rather than just delegate straight to
|
|
# the source_reflection, because the source_reflection may be polymorphic. We still
|
|
# need to respect the source_reflection's :primary_key option, though.
|
|
def association_primary_key(klass = nil)
|
|
# Get the "actual" source reflection if the immediate source reflection has a
|
|
# source reflection itself
|
|
actual_source_reflection.options[:primary_key] || primary_key(klass || self.klass)
|
|
end
|
|
|
|
# Gets an array of possible <tt>:through</tt> source reflection names in both singular and plural form.
|
|
#
|
|
# class Post < ActiveRecord::Base
|
|
# has_many :taggings
|
|
# has_many :tags, through: :taggings
|
|
# end
|
|
#
|
|
# tags_reflection = Post.reflect_on_association(:tags)
|
|
# tags_reflection.source_reflection_names
|
|
# # => [:tag, :tags]
|
|
#
|
|
def source_reflection_names
|
|
options[:source] ? [options[:source]] : [name.to_s.singularize, name].uniq
|
|
end
|
|
|
|
def source_reflection_name # :nodoc:
|
|
return @source_reflection_name if @source_reflection_name
|
|
|
|
names = [name.to_s.singularize, name].collect(&:to_sym).uniq
|
|
names = names.find_all { |n|
|
|
through_reflection.klass._reflect_on_association(n)
|
|
}
|
|
|
|
if names.length > 1
|
|
example_options = options.dup
|
|
example_options[:source] = source_reflection_names.first
|
|
ActiveSupport::Deprecation.warn \
|
|
"Ambiguous source reflection for through association. Please " \
|
|
"specify a :source directive on your declaration like:\n" \
|
|
"\n" \
|
|
" class #{active_record.name} < ActiveRecord::Base\n" \
|
|
" #{macro} :#{name}, #{example_options}\n" \
|
|
" end"
|
|
end
|
|
|
|
@source_reflection_name = names.first
|
|
end
|
|
|
|
def source_options
|
|
source_reflection.options
|
|
end
|
|
|
|
def through_options
|
|
through_reflection.options
|
|
end
|
|
|
|
def join_id_for(owner) # :nodoc:
|
|
source_reflection.join_id_for(owner)
|
|
end
|
|
|
|
def check_validity!
|
|
if through_reflection.nil?
|
|
raise HasManyThroughAssociationNotFoundError.new(active_record.name, self)
|
|
end
|
|
|
|
if through_reflection.polymorphic?
|
|
if has_one?
|
|
raise HasOneAssociationPolymorphicThroughError.new(active_record.name, self)
|
|
else
|
|
raise HasManyThroughAssociationPolymorphicThroughError.new(active_record.name, self)
|
|
end
|
|
end
|
|
|
|
if source_reflection.nil?
|
|
raise HasManyThroughSourceAssociationNotFoundError.new(self)
|
|
end
|
|
|
|
if options[:source_type] && !source_reflection.polymorphic?
|
|
raise HasManyThroughAssociationPointlessSourceTypeError.new(active_record.name, self, source_reflection)
|
|
end
|
|
|
|
if source_reflection.polymorphic? && options[:source_type].nil?
|
|
raise HasManyThroughAssociationPolymorphicSourceError.new(active_record.name, self, source_reflection)
|
|
end
|
|
|
|
if has_one? && through_reflection.collection?
|
|
raise HasOneThroughCantAssociateThroughCollection.new(active_record.name, self, through_reflection)
|
|
end
|
|
|
|
check_validity_of_inverse!
|
|
end
|
|
|
|
def constraints
|
|
scope_chain = source_reflection.constraints
|
|
scope_chain << scope if scope
|
|
scope_chain
|
|
end
|
|
|
|
def add_as_source(seed)
|
|
collect_join_reflections seed
|
|
end
|
|
|
|
def add_as_polymorphic_through(reflection, seed)
|
|
collect_join_reflections(seed + [PolymorphicReflection.new(self, reflection)])
|
|
end
|
|
|
|
def add_as_through(seed)
|
|
collect_join_reflections(seed + [self])
|
|
end
|
|
|
|
def collect_join_reflections(seed)
|
|
a = source_reflection.add_as_source seed
|
|
if options[:source_type]
|
|
through_reflection.add_as_polymorphic_through self, a
|
|
else
|
|
through_reflection.add_as_through a
|
|
end
|
|
end
|
|
|
|
protected
|
|
|
|
def actual_source_reflection # FIXME: this is a horrible name
|
|
source_reflection.send(:actual_source_reflection)
|
|
end
|
|
|
|
def primary_key(klass)
|
|
klass.primary_key || raise(UnknownPrimaryKey.new(klass))
|
|
end
|
|
|
|
def inverse_name; delegate_reflection.send(:inverse_name); end
|
|
|
|
private
|
|
def derive_class_name
|
|
# get the class_name of the belongs_to association of the through reflection
|
|
options[:source_type] || source_reflection.class_name
|
|
end
|
|
|
|
delegate_methods = AssociationReflection.public_instance_methods -
|
|
public_instance_methods
|
|
|
|
delegate(*delegate_methods, to: :delegate_reflection)
|
|
|
|
end
|
|
|
|
class PolymorphicReflection < ThroughReflection # :nodoc:
|
|
def initialize(reflection, previous_reflection)
|
|
@reflection = reflection
|
|
@previous_reflection = previous_reflection
|
|
end
|
|
|
|
def klass
|
|
@reflection.klass
|
|
end
|
|
|
|
def scope
|
|
@reflection.scope
|
|
end
|
|
|
|
def table_name
|
|
@reflection.table_name
|
|
end
|
|
|
|
def plural_name
|
|
@reflection.plural_name
|
|
end
|
|
|
|
def join_keys(association_klass)
|
|
@reflection.join_keys(association_klass)
|
|
end
|
|
|
|
def type
|
|
@reflection.type
|
|
end
|
|
|
|
def constraints
|
|
@reflection.constraints + [source_type_info]
|
|
end
|
|
|
|
def source_type_info
|
|
type = @previous_reflection.foreign_type
|
|
source_type = @previous_reflection.options[:source_type]
|
|
lambda { |object| where(type => source_type) }
|
|
end
|
|
end
|
|
|
|
class RuntimeReflection < PolymorphicReflection # :nodoc:
|
|
attr_accessor :next
|
|
|
|
def initialize(reflection, association)
|
|
@reflection = reflection
|
|
@association = association
|
|
end
|
|
|
|
def klass
|
|
@association.klass
|
|
end
|
|
|
|
def table_name
|
|
klass.table_name
|
|
end
|
|
|
|
def constraints
|
|
@reflection.constraints
|
|
end
|
|
|
|
def source_type_info
|
|
@reflection.source_type_info
|
|
end
|
|
|
|
def alias_candidate(name)
|
|
"#{plural_name}_#{name}_join"
|
|
end
|
|
|
|
def alias_name
|
|
Arel::Table.new(table_name)
|
|
end
|
|
|
|
def all_includes; yield; end
|
|
end
|
|
end
|
|
end
|