I need a metadata category property that causes all metadata tags in that category that are assigned to a topic to be injected into the role attribute of the topic's <section> element when it is built, and for them to be injected when it's built with the csprocessor.

So, for example, I tag my topic with "Programming Language":"Python" and it comes out with:

<section role="programming-language-python">

The form should be (pseudocode):

for each Topic.Tags as Tag
  if Tag.ParentCategory.hasProperty("inject as role")
    role=role+(Category.toLowerCase()+"-"+Tag.toLowerCase).escapeSpaces("-") + " "; 

So the role attribute will be a space-separated list of injectable tags with internal spaces replaced with "-".

I know that tag names are guaranteed unique at this point, but I think putting the category will make the meaning clearer in the html output (where the role is rendered as a class attribute).