Thread: Making category accessible only to listing owners

Making category accessible only to listing owners

I have a category that I want to be accessible only to people who have approved listing on the site.
Can someone suggest what needs to be edited and which files ?
I know it would not be very easy but I am sure it can be done by putting a loop with condition "if $author has approved listing" then show category content otherwise "Please post a listing to access this category".
I just need a code that checks - if $author >= 1 approved listings also it would be great if someone can suggest a function so that it can be called even for single listing that belongs to this restricted category.