I have a section where each item has its own URL e.g: news/{slug}
The Entry Template for this section is: news/news_detail
For each post I would like to have a link to a unique page which is populated with information from the fields from the parent post/group, e.g news.
The slug would look something like: news/{slug}/extra
The Entry Template for the news_detail page has a rich text field: additional
To make this more complicated, the link to this page will be visible only if the "additional" field is populated with data. And finally each "extra" page should have a link back to the originating post.
I had considered using a simple JavaScript toggle, but having urls for the content is more important in this instance, so not an option.
Thank you for any pointers as I am not sure where to start.