[web-devel] [Yesod] an API which return Root Relative URL.

Hi I want an api which return Root Relative URL. I've been developing wiki clone. When a writer select and click an image from photo galary in order to insert a image, click event insert a wiki image link like as "". But I think this - wiki contents has self Absolute URL - is not good. Is there the API? I want the api, but i remove approot string from Absolute URL, now.