How to require an Array param, which have string or null elements

[chicaco]

I have a validation like so:
requires :names, type: Array[String]

and I also want to accept a null element.
e.g. [null], [null, "name"]

but would not work.
requires :names, type: Array[String]
and
requires :names, type: Array[String], coerce_with: ->(val) { val.compact if val.is_a?(Array) }

How can I accept array including String and null?

[dblock]

It's a good question.

For a POST request with a type that clearly delineates nil vs. an empty value vs. something else, like JSON, I think you can "just do it".

For a GET request I don't think you can because there's no way to distinguish nil and an empty string in a query. How would you make an HTTP request with an array containing nils in, say, curl?

[dblock]

I'll close this, you should bring it up on the mailing list, http://groups.google.com/group/ruby-grape.