Can unused items get automatically removed from user categories?

[ownedbycats]

I have a user category, @On Kobo. I have an item in that category, '[Send to Device]' (from an enumerated #kobostatus) column. A lot of times, it's unused - I use it to keep track of books to re-upload to device.

Recently. I've found [Send to Device] go missing from my user category several times. (Not hidden; I have to open the editor and re-add it.) This does not happen with any other items in my user category, which makes me think it may be related to [Send to Device] not always being in-use and perhaps somehow getting removed due to being empty.

Is this a feature that I somehow never noticed before, a bug, or just some weird gremlin?

[chaley]

Originally Posted by ownedbycats

I have a user category, @On Kobo. I have an item in that category, '[Send to Device]' (from an enumerated #kobostatus) column. A lot of times, it's unused - I use it to keep track of books to re-upload to device.

Recently. I've found [Send to Device] go missing from my user category several times. (Not hidden; I have to open the editor and re-add it.) This does not happen with any other items in my user category, which makes me think it may be related to [Send to Device] not always being in-use and perhaps somehow getting removed due to being empty.

Is this a feature that I somehow never noticed before, a bug, or just some weird gremlin?

If '[Send to Device]' is a category item in a user category then it will be removed if it exists in no book. Why? Because an item must actually exist in some book for it to be in calibre's database. Note that information about the items, e.g., their links, will also disappear.

When it gets removed is a harder question. IIRC using Manage Categories will remove any leftover non-existent items. Probably manipulating the parent user category (right-clicks etc) will clean the items.

And to head off the probably enhancement request: no, I don't want to either leave non-existent items in the category list or add some way to lock non-existant items in a user category. The first would be unreliable and would lead to a very large category list, costing performance when displaying them. The second is more work than I want to do.

You can solve this problem by having a special book that contains items that you want never to disappear.

[ownedbycats]

Would running an action chain that changes the value of #kobostatus on book(s) be enough to clean the item?

The other thing I think of is editing the category itself - I added and removed several items from another column that has items in @On Kobo, which meant I had to use 'manage user categories' to adjust it. It's possible I never did this before while [Send to Device] was empty.

Is this a recent change? I've never really noticed it happen before, except in the last few weeks. There was the change to remove duplicate category items, but I'm not sure that would affect this.

[chaley]

Originally Posted by ownedbycats

Would running an action chain that changes the value of #kobostatus on book(s) be enough to clean the item?

Depends on how the change is done. If it uses only db.cache then I don't think it will. Touching the list of user categories can do the check.

The other thing I think of is editing the category itself - I added and removed several items from another column that has items in @On Kobo, which meant I had to use 'manage user categories' to adjust it. It's possible I never did this before while [Send to Device] was empty.

Manage User Categories removes all items that no longer exist.

Is this a recent change? I've never really noticed it happen before, except in the last few weeks. There was the change to remove duplicate category items, but I'm not sure that would affect this.

Yes and no. Non-existent items were removed in some cases since forever. Changes in August 2022 generalized this behavior.

IMO removing user category items that no longer exist in the database is the correct behavior.

[ownedbycats]

A single-field edit based on a stored GPM template. I'm not sure if that would use db.cache or not.

[capink]

Originally Posted by chaley

Depends on how the change is done. If it uses only db.cache then I don't think it will.

Originally Posted by ownedbycats

A single-field edit based on a stored GPM template. I'm not sure if that would use db.cache or not.

It uses db.new_api.set_field() to change the values.

Originally Posted by chaley

IMO removing user category items that no longer exist in the database is the correct behavior.

I don't edit my user categories directly in calibre. Instead, I edit them in a csv file, and import them into calibre using the Category Tags plugin. This might be a solution for anyone who does not want to lose their user categories.

[BetterRed]

Originally Posted by chaley

IMO removing user category items that no longer exist in the database is the correct behavior.

If you didn't think that, then you'd have me knocking on your door asking why can't all categories have an option that would make them persistent - what I'd call the controlled vocabulary option

BR

[ownedbycats]

I mostly found it odd as #kobostatus is an enumerated column - It wouldn't have been so confusing for a regular text column where the entry disappears completely if you remove it.

It's not a big issue, I can just make sure not to edit when the entry is empty - by which I mean queue up a book to be sent to device

[ownedbycats]

also, the single-field edit didn't remove the item - here it's flagged as 'not in library.' Oddly, pressing 'ok' to save doesn't remove it from list as I would have expected from post #2 and previously seen behaviour)



Since the category editor was mentioned, I still think the most likely situation is it happened when I was editing items in #kobocoll (merging and renaming) which would've updated the user-category. Though [Send to Device] is in #kobostatus, so I'm not sure.