I’ve seen the ticket in trello on adding the mass-rename feature to the series editor, which was done in 2014.
Was there a particular reason not to include a preview of the changes in that dialog? In case there is, maybe alternatively, Sonarr could offer some kind of indication of possible renames? This way, users could easily tell which series to examine by using the per-series rename dialog. Right now, the only choice seems to be either going through all series manually or using the series editor without actually knowing what’s going to happen.
It could be thousands of items and would be a massive performance hit.
The preview is meant as a way to show you what the files will look like on an actual episode, not just an example. I can’t see many people really wanting to pour through thousands of episodes to make sure they’re happy with it.
Whats the end goal with a preview for everything or at least a summary of which series will actually have changes applied? I’d say this is a non-trivial change and definitely wouldn’t be high on our priority list, but at the moment I don’t see us doing it.
Of course, if someone explicitly modifies the global episode format and wants to apply that to all files, they know exactly what’s going to happen and a full preview of all changes is not useful at all.
In my particular scenario, however, I’m migrating a lot of existing files from SB to Sonarr and for every show there are just a few files that need some renaming. These kind of changes are actually so few in total to inspect each one manually. So I’m not suggesting to have a huge preview in the mass-renaming dialog, but I’d just like to see the same reasoning applied to it as to the regular, per-show dialog: If there happen to be just a dozen changes in all series, why not preview them the same way a dozen changes are previewed in the single-show renamer?
Is the performance impact of a large preview due to the creation of the preview on the server-side or mostly because it needs to be transferred to the client and displayed? If it’s the latter, maybe the preview could be paginated and thereby transferred in small chunks? If that’s too complicated (given the admittedly low priority of this), truncating the preview to the first $n changes and providing the total number would be just fine, too, IMHO.
Again, from my point of view, this is not about giving an example of the changes, but simply either showing them all if they’re few enough to be manually inspected, or if not, telling the user, how many changes there will be so they can decide whether they want it done “blindly” or rather check out each show individually.