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Diffstat (limited to 'activerecord/lib/active_record/scoping/default.rb')
| -rw-r--r-- | activerecord/lib/active_record/scoping/default.rb | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/scoping/default.rb b/activerecord/lib/active_record/scoping/default.rb new file mode 100644 index 0000000000..db833fc7f1 --- /dev/null +++ b/activerecord/lib/active_record/scoping/default.rb @@ -0,0 +1,146 @@ +require 'active_support/concern' +require 'active_support/deprecation' + +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 that you use the block form of unscoped because chaining + # unscoped with <tt>scope</tt> does not work. Assuming that + # <tt>published</tt> is a <tt>scope</tt>, 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 <tt>default_scope</tt> 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 pass any object which responds to <tt>call</tt> to the <tt>default_scope</tt> + # macro, and it will be called when building the default scope.) + # + # If you use multiple <tt>default_scope</tt> 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 <tt>default_scope</tt> 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 = nil) + scope = Proc.new if block_given? + + if scope.is_a?(Relation) || !scope.respond_to?(:call) + ActiveSupport::Deprecation.warn( + "Calling #default_scope without a block is deprecated. For example instead " \ + "of `default_scope where(color: 'red')`, please use " \ + "`default_scope { where(color: 'red') }`. (Alternatively you can just redefine " \ + "self.default_scope.)" + ) + end + + self.default_scopes = default_scopes + [scope] + end + + def build_default_scope #:nodoc: + if !Base.is_a?(method(:default_scope).owner) + # The user has defined their own default scope method, so call that + 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?(Relation) && scope.respond_to?(:call) + default_scope.merge(unscoped { 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 |