module ActiveRecord::Scoping::Default::ClassMethods
Public Instance Methods
Returns a scope for the model without the previously set scopes.
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" Post.where(published: false).unscoped.all # Fires "SELECT * FROM posts"
This method also accepts a block. All queries inside the block will not use the previously set scopes.
Post.unscoped { Post.limit(10) # Fires "SELECT * FROM posts LIMIT 10" }
# File lib/active_record/scoping/default.rb, line 33 def unscoped block_given? ? relation.scoping { yield } : relation end
Private Instance Methods
# File lib/active_record/scoping/default.rb, line 102 def build_default_scope(relation = relation()) return if abstract_class? if default_scope_override.nil? self.default_scope_override = !Base.is_a?(method(:default_scope).owner) end if default_scope_override # The user has defined their own default scope method, so call that evaluate_default_scope do relation.scoping { default_scope } end elsif default_scopes.any? evaluate_default_scope do default_scopes.inject(relation) do |default_scope, scope| scope = scope.respond_to?(:to_proc) ? scope : scope.method(:call) default_scope.instance_exec(&scope) || default_scope end end end end
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 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
# File lib/active_record/scoping/default.rb, line 88 def default_scope(scope = nil, &block) # :doc: scope = block if block_given? if scope.is_a?(Relation) || !scope.respond_to?(:call) raise ArgumentError, "Support for calling #default_scope without a block is removed. 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 += [scope] 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 scopeā¦
# File lib/active_record/scoping/default.rb, line 135 def evaluate_default_scope return if ignore_default_scope? begin self.ignore_default_scope = true yield ensure self.ignore_default_scope = false end end
# File lib/active_record/scoping/default.rb, line 128 def ignore_default_scope=(ignore) ScopeRegistry.set_value_for(:ignore_default_scope, base_class, ignore) end
# File lib/active_record/scoping/default.rb, line 124 def ignore_default_scope? ScopeRegistry.value_for(:ignore_default_scope, base_class) end