No all UDL/AC/FL or Theme files on the internet are in the UDL and Theme Collections, unfortunately.
Thus, it would be nice if a "download external file(s)" button existed. If the UDL tab is selected, it could have URLs for each of the UDL/AC/FL. If AC or FL or TH tabs are selected, it could just prompt for the one file. That way, the CollectionInterface could do all its safety checks and directory locating for you, even if the author of the UDL/AC/FL/TH hasn't bothered to put it in one of the Collections
No all UDL/AC/FL or Theme files on the internet are in the UDL and Theme Collections, unfortunately.
Thus, it would be nice if a "download external file(s)" button existed. If the UDL tab is selected, it could have URLs for each of the UDL/AC/FL. If AC or FL or TH tabs are selected, it could just prompt for the one file. That way, the CollectionInterface could do all its safety checks and directory locating for you, even if the author of the UDL/AC/FL/TH hasn't bothered to put it in one of the Collections