如果我有一个像下面这样的类,那我怎么知道一个祖先是一个类,一个模块呢？
ActiveRecord::Base.send(:include,SomeLibrary) class Group < ActiveRecord::Base include SomeLibrary::Core end class SubGroup < Group end ancestor_names = SubGroup.ancestors.map(&:name) puts ancestor_names.inspect #=> [ "SubGroup","SomeLibrary::Core::InstanceMethods","SomeLibrary::Core","Group","ActiveRecord::Base","SomeLibrary","ActiveRecord::Aggregations","ActiveRecord::Transactions","ActiveRecord::Reflection","ActiveRecord::Batches","ActiveRecord::Calculations","ActiveRecord::Serialization","ActiveRecord::AutosaveAssociation","ActiveRecord::NestedAttributes","ActiveRecord::Associations","ActiveRecord::AssociationPreload","ActiveRecord::NamedScope","ActiveRecord::Callbacks","ActiveRecord::Observing","ActiveRecord::Timestamp","ActiveRecord::Dirty","ActiveRecord::AttributeMethods","ActiveRecord::Locking::Optimistic","ActiveRecord::Locking::Pessimistic","ActiveSupport::Callbacks","ActiveRecord::Validations","Object","Mocha::ObjectMethods","JSON::Pure::Generator::GeneratorMethods::Object","ActiveSupport::Dependencies::Loadable","Base64::Deprecated","Base64","PP::ObjectMixin","Kernel" ]
我想要做这样的事情：
ancestor_names.each do |name|
if class?(name)
puts "#{name} is a Class"
elsif module?(name)
puts "#{name} is a Module"
end
end
要么…
SubGroup.ancestor_classes #=> only the classes in the tree SubGroup.ancestor_modules #=> only the modules in the tree
它归结为,你如何检查一个对象是一个类还是一个模块？
解决方法
那么这就是
included_modules的,所以你可能正在寻找的是：
SubGroup.included_modules #=> module ancestors SubGroup.ancestors - SubGroup.included_modules #=> class ancestors
或者,使用辅助方法：
class Class
def ancestor_classes
ancestors - included_modules
end
end
SubGroup.included_modules #=> module ancestors
SubGroup.ancestor_classes #=> class ancestors