diff options
Diffstat (limited to 'activerecord/lib/active_record/named_scope.rb')
| -rw-r--r-- | activerecord/lib/active_record/named_scope.rb | 113 |
1 files changed, 94 insertions, 19 deletions
diff --git a/activerecord/lib/active_record/named_scope.rb b/activerecord/lib/active_record/named_scope.rb index d291632260..f1df04950b 100644 --- a/activerecord/lib/active_record/named_scope.rb +++ b/activerecord/lib/active_record/named_scope.rb @@ -9,11 +9,6 @@ module ActiveRecord module NamedScope extend ActiveSupport::Concern - included do - class_attribute :scopes - self.scopes = {} - end - module ClassMethods # Returns an anonymous \scope. # @@ -35,7 +30,13 @@ module ActiveRecord if options scoped.apply_finder_options(options) else - current_scoped_methods ? relation.merge(current_scoped_methods) : relation.clone + if current_scope + current_scope.clone + else + scope = relation.clone + scope.default_scoped = true + scope + end end end @@ -50,6 +51,14 @@ module ActiveRecord # The above calls to <tt>scope</tt> define class methods Shirt.red and Shirt.dry_clean_only. Shirt.red, # in effect, represents the query <tt>Shirt.where(:color => 'red')</tt>. # + # Note that this is simply 'syntactic sugar' for defining an actual class method: + # + # class Shirt < ActiveRecord::Base + # def self.red + # where(:color => 'red') + # end + # end + # # Unlike <tt>Shirt.find(...)</tt>, however, the object returned by Shirt.red is not an Array; it # resembles the association object constructed by a <tt>has_many</tt> declaration. For instance, # you can invoke <tt>Shirt.red.first</tt>, <tt>Shirt.red.count</tt>, <tt>Shirt.red.where(:size => 'small')</tt>. @@ -73,14 +82,34 @@ module ActiveRecord # then <tt>elton.shirts.red.dry_clean_only</tt> will return all of Elton's red, dry clean # only shirts. # - # Named \scopes can also be procedural: + # If you need to pass parameters to a scope, define it as a normal method: # # class Shirt < ActiveRecord::Base - # scope :colored, lambda {|color| where(:color => color) } + # def self.colored(color) + # where(:color => color) + # end # end # # In this example, <tt>Shirt.colored('puce')</tt> finds all puce shirts. # + # Note that scopes defined with \scope will be evaluated when they are defined, rather than + # when they are used. For example, the following would be incorrect: + # + # class Post < ActiveRecord::Base + # scope :recent, where('published_at >= ?', Time.now - 1.week) + # end + # + # The example above would be 'frozen' to the <tt>Time.now</tt> value when the <tt>Post</tt> + # class was defined, and so the resultant SQL query would always be the same. The correct + # way to do this would be via a class method, which will re-evaluate the scope each time + # it is called: + # + # class Post < ActiveRecord::Base + # def self.recent + # where('published_at >= ?', Time.now - 1.week) + # end + # end + # # Named \scopes can also have extensions, just as with <tt>has_many</tt> declarations: # # class Shirt < ActiveRecord::Base @@ -91,6 +120,18 @@ module ActiveRecord # end # end # + # The above could also be written as a class method like so: + # + # class Shirt < ActiveRecord::Base + # def self.red + # where(:color => 'red').extending do + # def dom_id + # 'red_shirts' + # end + # end + # end + # end + # # Scopes can also be used while creating/building a record. # # class Article < ActiveRecord::Base @@ -99,34 +140,68 @@ module ActiveRecord # # Article.published.new.published # => true # Article.published.create.published # => true + # + # Class methods on your model are automatically available + # on scopes. Assuming the following setup: + # + # class Article < ActiveRecord::Base + # scope :published, where(:published => true) + # scope :featured, where(:featured => true) + # + # def self.latest_article + # order('published_at desc').first + # end + # + # def self.titles + # map(&:title) + # end + # + # end + # + # We are able to call the methods like this: + # + # Article.published.featured.latest_article + # Article.featured.titles + def scope(name, scope_options = {}) name = name.to_sym valid_scope_name?(name) extension = Module.new(&Proc.new) if block_given? + if !scope_options.is_a?(Relation) && scope_options.respond_to?(:call) + ActiveSupport::Deprecation.warn <<-WARN +Passing a proc (or other object that responds to #call) to scope is deprecated. If you need your scope to be lazily evaluated, or takes parameters, please define it as a normal class method instead. For example, change this: + +class Post < ActiveRecord::Base + scope :unpublished, lambda { where('published_at > ?', Time.now) } +end + +To this: + +class Post < ActiveRecord::Base + def self.unpublished + where('published_at > ?', Time.now) + end +end + WARN + end + scope_proc = lambda do |*args| options = scope_options.respond_to?(:call) ? scope_options.call(*args) : scope_options + options = scoped.apply_finder_options(options) if options.is_a?(Hash) - relation = if options.is_a?(Hash) - scoped.apply_finder_options(options) - elsif options - scoped.merge(options) - else - scoped - end + relation = scoped.merge(options) extension ? relation.extending(extension) : relation end - self.scopes = self.scopes.merge name => scope_proc - - singleton_class.send(:redefine_method, name, &scopes[name]) + singleton_class.send(:redefine_method, name, &scope_proc) end protected def valid_scope_name?(name) - if !scopes[name] && respond_to?(name, true) + if respond_to?(name, true) logger.warn "Creating scope :#{name}. " \ "Overwriting existing method #{self.name}.#{name}." end |