diff options
Diffstat (limited to 'activerecord/lib/active_record/scoping/named.rb')
| -rw-r--r-- | activerecord/lib/active_record/scoping/named.rb | 33 |
1 files changed, 20 insertions, 13 deletions
diff --git a/activerecord/lib/active_record/scoping/named.rb b/activerecord/lib/active_record/scoping/named.rb index 7b62626896..103569c84d 100644 --- a/activerecord/lib/active_record/scoping/named.rb +++ b/activerecord/lib/active_record/scoping/named.rb @@ -9,7 +9,7 @@ module ActiveRecord extend ActiveSupport::Concern module ClassMethods - # Returns an <tt>ActiveRecord::Relation</tt> scope object. + # Returns an ActiveRecord::Relation scope object. # # posts = Post.all # posts.size # Fires "select count(*) from posts" and returns the count @@ -20,7 +20,7 @@ module ActiveRecord # fruits = fruits.limit(10) if limited? # # You can define a scope that applies to all finders using - # <tt>ActiveRecord::Base.default_scope</tt>. + # {default_scope}[rdoc-ref:Scoping::Default::ClassMethods#default_scope]. def all if current_scope current_scope.clone @@ -39,8 +39,13 @@ module ActiveRecord end end - # Adds a class method for retrieving and querying objects. A \scope - # represents a narrowing of a database query, such as + # Adds a class method for retrieving and querying objects. + # The method is intended to return an ActiveRecord::Relation + # object, which is composable with other scopes. + # If it returns nil or false, an + # {all}[rdoc-ref:Scoping::Named::ClassMethods#all] scope is returned instead. + # + # A \scope represents a narrowing of a database query, such as # <tt>where(color: :red).select('shirts.*').includes(:washing_instructions)</tt>. # # class Shirt < ActiveRecord::Base @@ -48,12 +53,12 @@ module ActiveRecord # scope :dry_clean_only, -> { joins(:washing_instructions).where('washing_instructions.dry_clean_only = ?', true) } # end # - # The above calls to +scope+ define class methods <tt>Shirt.red</tt> and + # The above calls to #scope define class methods <tt>Shirt.red</tt> and # <tt>Shirt.dry_clean_only</tt>. <tt>Shirt.red</tt>, in effect, # represents the query <tt>Shirt.where(color: 'red')</tt>. # # You should always pass a callable object to the scopes defined - # with +scope+. This ensures that the scope is re-evaluated each + # with #scope. This ensures that the scope is re-evaluated each # time it is called. # # Note that this is simply 'syntactic sugar' for defining an actual @@ -66,14 +71,15 @@ module ActiveRecord # end # # Unlike <tt>Shirt.find(...)</tt>, however, the object returned by - # <tt>Shirt.red</tt> is not an Array; it resembles the association object - # constructed by a +has_many+ declaration. For instance, you can invoke - # <tt>Shirt.red.first</tt>, <tt>Shirt.red.count</tt>, + # <tt>Shirt.red</tt> is not an Array but an ActiveRecord::Relation, + # which is composable with other scopes; it resembles the association object + # constructed by a {has_many}[rdoc-ref:Associations::ClassMethods#has_many] + # declaration. For instance, you can invoke <tt>Shirt.red.first</tt>, <tt>Shirt.red.count</tt>, # <tt>Shirt.red.where(size: 'small')</tt>. Also, just as with the # association objects, named \scopes act like an Array, implementing # Enumerable; <tt>Shirt.red.each(&block)</tt>, <tt>Shirt.red.first</tt>, # and <tt>Shirt.red.inject(memo, &block)</tt> all behave as if - # <tt>Shirt.red</tt> really was an Array. + # <tt>Shirt.red</tt> really was an array. # # These named \scopes are composable. For instance, # <tt>Shirt.red.dry_clean_only</tt> will produce all shirts that are @@ -84,7 +90,8 @@ module ActiveRecord # # All scopes are available as class methods on the ActiveRecord::Base # descendant upon which the \scopes were defined. But they are also - # available to +has_many+ associations. If, + # available to {has_many}[rdoc-ref:Associations::ClassMethods#has_many] + # associations. If, # # class Person < ActiveRecord::Base # has_many :shirts @@ -93,8 +100,8 @@ 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 have extensions, just as with +has_many+ - # declarations: + # \Named scopes can also have extensions, just as with + # {has_many}[rdoc-ref:Associations::ClassMethods#has_many] declarations: # # class Shirt < ActiveRecord::Base # scope :red, -> { where(color: 'red') } do |