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-rw-r--r--activerecord/lib/active_record/associations/association.rb106
1 files changed, 77 insertions, 29 deletions
diff --git a/activerecord/lib/active_record/associations/association.rb b/activerecord/lib/active_record/associations/association.rb
index ca8c7794e0..cf22b850b9 100644
--- a/activerecord/lib/active_record/associations/association.rb
+++ b/activerecord/lib/active_record/associations/association.rb
@@ -17,9 +17,25 @@ module ActiveRecord
# CollectionAssociation
# HasManyAssociation + ForeignAssociation
# HasManyThroughAssociation + ThroughAssociation
+ #
+ # Associations in Active Record are middlemen between the object that
+ # holds the association, known as the <tt>owner</tt>, and the associated
+ # result set, known as the <tt>target</tt>. Association metadata is available in
+ # <tt>reflection</tt>, which is an instance of <tt>ActiveRecord::Reflection::AssociationReflection</tt>.
+ #
+ # For example, given
+ #
+ # class Blog < ActiveRecord::Base
+ # has_many :posts
+ # end
+ #
+ # blog = Blog.first
+ #
+ # The association of <tt>blog.posts</tt> has the object +blog+ as its
+ # <tt>owner</tt>, the collection of its posts as <tt>target</tt>, and
+ # the <tt>reflection</tt> object represents a <tt>:has_many</tt> macro.
class Association #:nodoc:
attr_reader :owner, :target, :reflection
- attr_accessor :inversed
delegate :options, to: :reflection
@@ -41,7 +57,9 @@ module ActiveRecord
end
# Reloads the \target and returns +self+ on success.
- def reload
+ # The QueryCache is cleared if +force+ is true.
+ def reload(force = false)
+ klass.connection.clear_query_cache if force && klass
reset
reset_scope
load_target
@@ -67,7 +85,7 @@ module ActiveRecord
#
# Note that if the target has not been loaded, it is not considered stale.
def stale_target?
- !inversed && loaded? && @stale_state != stale_state
+ !@inversed && loaded? && @stale_state != stale_state
end
# Sets the target of this association to <tt>\target</tt>, and the \loaded flag to +true+.
@@ -80,53 +98,44 @@ module ActiveRecord
target_scope.merge!(association_scope)
end
- # The scope for this association.
- #
- # Note that the association_scope is merged into the target_scope only when the
- # scope method is called. This is because at that point the call may be surrounded
- # by scope.scoping { ... } or with_scope { ... } etc, which affects the scope which
- # actually gets built.
- def association_scope
- if klass
- @association_scope ||= AssociationScope.scope(self)
- end
- end
-
def reset_scope
@association_scope = nil
end
# Set the inverse association, if possible
def set_inverse_instance(record)
- if invertible_for?(record)
- inverse = record.association(inverse_reflection_for(record).name)
- inverse.target = owner
- inverse.inversed = true
+ if inverse = inverse_association_for(record)
+ inverse.inversed_from(owner)
+ end
+ record
+ end
+
+ def set_inverse_instance_from_queries(record)
+ if inverse = inverse_association_for(record)
+ inverse.inversed_from_queries(owner)
end
record
end
# Remove the inverse association, if possible
def remove_inverse_instance(record)
- if invertible_for?(record)
- inverse = record.association(inverse_reflection_for(record).name)
- inverse.target = nil
- inverse.inversed = false
+ if inverse = inverse_association_for(record)
+ inverse.inversed_from(nil)
end
end
+ def inversed_from(record)
+ self.target = record
+ @inversed = !!record
+ end
+ alias :inversed_from_queries :inversed_from
+
# Returns the class of the target. belongs_to polymorphic overrides this to look at the
# polymorphic_type field on the owner.
def klass
reflection.klass
end
- # Can be overridden (i.e. in ThroughAssociation) to merge in other scopes (i.e. the
- # through association's scope)
- def target_scope
- AssociationRelation.create(klass, self).merge!(klass.all)
- end
-
def extensions
extensions = klass.default_extensions | reflection.extensions
@@ -187,6 +196,38 @@ module ActiveRecord
end
private
+ def find_target
+ scope = self.scope
+ return scope.to_a if skip_statement_cache?(scope)
+
+ conn = klass.connection
+ sc = reflection.association_scope_cache(conn, owner) do |params|
+ as = AssociationScope.create { params.bind }
+ target_scope.merge!(as.scope(self))
+ end
+
+ binds = AssociationScope.get_bind_values(owner, reflection.chain)
+ sc.execute(binds, conn) { |record| set_inverse_instance(record) } || []
+ end
+
+ # The scope for this association.
+ #
+ # Note that the association_scope is merged into the target_scope only when the
+ # scope method is called. This is because at that point the call may be surrounded
+ # by scope.scoping { ... } or unscoped { ... } etc, which affects the scope which
+ # actually gets built.
+ def association_scope
+ if klass
+ @association_scope ||= AssociationScope.scope(self)
+ end
+ end
+
+ # Can be overridden (i.e. in ThroughAssociation) to merge in other scopes (i.e. the
+ # through association's scope)
+ def target_scope
+ AssociationRelation.create(klass, self).merge!(klass.scope_for_association)
+ end
+
def scope_for_create
scope.scope_for_create
end
@@ -240,6 +281,12 @@ module ActiveRecord
end
end
+ def inverse_association_for(record)
+ if invertible_for?(record)
+ record.association(inverse_reflection_for(record).name)
+ end
+ end
+
# Can be redefined by subclasses, notably polymorphic belongs_to
# The record parameter is necessary to support polymorphic inverses as we must check for
# the association in the specific class of the record.
@@ -269,6 +316,7 @@ module ActiveRecord
def build_record(attributes)
reflection.build_association(attributes) do |record|
initialize_attributes(record, attributes)
+ yield(record) if block_given?
end
end