4
I think you are on the right track.
An "album" may need to be made by you, but if there are core classes already in place which are useful, use them - that's why they are there
![](https://xoops.org/uploads/smil3dbd4d6422f04.gif)
Depending on your needs for a category class, you could use the XoopsTopic - also depending on whether you would need independent categories in the gallery system, since the XoopsTopic class is also used by the News module.
If you need more than that, you can always extend e.g. XoopsTopic with your category class and just override the methods, you need done differently.