require 'active_support/concern' module ActiveRecord module Scoping module Default extend ActiveSupport::Concern included do # Stores the default scope for the class config_attribute :default_scopes self.default_scopes = [] end module ClassMethods # Returns a scope for the model without the default_scope. # # class Post < ActiveRecord::Base # def self.default_scope # where :published => true # end # end # # Post.all # Fires "SELECT * FROM posts WHERE published = true" # Post.unscoped.all # Fires "SELECT * FROM posts" # # This method also accepts a block. All queries inside the block will # not use the default_scope: # # Post.unscoped { # Post.limit(10) # Fires "SELECT * FROM posts LIMIT 10" # } # # It is recommended to use the block form of unscoped because chaining # unscoped with scope does not work. Assuming that # published is a scope, the following two statements # are equal: the default_scope is applied on both. # # Post.unscoped.published # Post.published def unscoped #:nodoc: block_given? ? relation.scoping { yield } : relation end def before_remove_const #:nodoc: self.current_scope = nil end protected # Use this macro in your model to set a default scope for all operations on # the model. # # class Article < ActiveRecord::Base # default_scope where(:published => true) # end # # Article.all # => SELECT * FROM articles WHERE published = true # # The default_scope is also applied while creating/building a record. It is not # applied while updating a record. # # Article.new.published # => true # Article.create.published # => true # # You can also use default_scope with a block, in order to have it lazily evaluated: # # class Article < ActiveRecord::Base # default_scope { where(:published_at => Time.now - 1.week) } # end # # (You can also pass any object which responds to call to the default_scope # macro, and it will be called when building the default scope.) # # If you use multiple default_scope declarations in your model then they will # be merged together: # # class Article < ActiveRecord::Base # default_scope where(:published => true) # default_scope where(:rating => 'G') # end # # Article.all # => SELECT * FROM articles WHERE published = true AND rating = 'G' # # This is also the case with inheritance and module includes where the parent or module # defines a default_scope and the child or including class defines a second one. # # If you need to do more complex things with a default scope, you can alternatively # define it as a class method: # # class Article < ActiveRecord::Base # def self.default_scope # # Should return a scope, you can call 'super' here etc. # end # end def default_scope(scope = {}) scope = Proc.new if block_given? self.default_scopes = default_scopes + [scope] end def build_default_scope #:nodoc: if method(:default_scope).owner != ActiveRecord::Scoping::Default::ClassMethods evaluate_default_scope { default_scope } elsif default_scopes.any? evaluate_default_scope do default_scopes.inject(relation) do |default_scope, scope| if scope.is_a?(Hash) default_scope.apply_finder_options(scope) elsif !scope.is_a?(Relation) && scope.respond_to?(:call) default_scope.merge(scope.call) else default_scope.merge(scope) end end end end end def ignore_default_scope? #:nodoc: Thread.current["#{self}_ignore_default_scope"] end def ignore_default_scope=(ignore) #:nodoc: Thread.current["#{self}_ignore_default_scope"] = ignore end # The ignore_default_scope flag is used to prevent an infinite recursion situation where # a default scope references a scope which has a default scope which references a scope... def evaluate_default_scope return if ignore_default_scope? begin self.ignore_default_scope = true yield ensure self.ignore_default_scope = false end end end end end end