How to retrieve downloadUrl of derived images?

[phorward]

This topic was discussed lately. A FileBone has derives, but in the json-renderer there's no way to get these derived downloadUrls except for the original file which is injected along with the dlkey. There's currently no solution or workaround. In the html-renderer, there's a built-in Jinja function to retrieve derived URLs for a given file. A solution for this needs to be found for json-renderer or by using an externally callable function for retrieving the URL.

[theVAX]

In my opinion, for files that are public, i.e. have no expiry period, the signed download urls, including those of the preview images etc., should be stored directly on the filebone and also be part of the server response. Otherwise, paths should be provided under which the download urls can be retrieved.

[phorward]

Is this fixed by #1241?

[phorward]

Seen as fixed by #1305, but #1290 also refers to it.