How can I get all list of scopes in ActiveRecord 3.x

问题

I am using ActiveRecord with Rails 3.

I defined scopes in my model. How can I get the list of all scopes of that model?

Previously I could use Model.scopes

OR Can I check a scope is defined or not? Something like Model.scope_defined?("scope_name")

Thanks in advance.

回答1:

You can see if a scope is defined or not this way

Model.send(:valid_scope_name?, :scope_name)

it will return true if it does exist and nil if it does not.

If you check the source code of valid_scope_name?, you see that you can just test it using respond_to? and then avoid the logging part.

Model.respond_to?(scope_name, true)

来源：https://stackoverflow.com/questions/12616175/how-can-i-get-all-list-of-scopes-in-activerecord-3-x