handled screen for a backpack

[wispy haven]

Im trying to make an item kinda like a backpack. So when you hold it and press a key, a screen opens and you can move items in and out from the inventory.

Can someone tell me what are the steps in doing something like that?

The main questions i have in mind are:

• How would an inventory in a item look like? Is it a nbt list or something else
• how to create a screen handler from an item: where to get the syncId and the inventory from the item
• how to open a handled screen

I tried to look at how some mods do it, but i only found over complicated examples, and not being really familiar with screens and handled screens i was going crazy.
So even a simple mod example would help a lot

(Please ping me when answering)

[ember elm]

for screenhandler: https://fabricmc.net/wiki/tutorial:screenhandler
you can store the data as a nbt list in <1.20.5, or a custom component in >=1.20.5. see how the bundle item does it

[wispy haven]

For a screen handler i need a syncId, which is already provided for block entities, but in this case i dont have a block entity. so how would i get one?

[ember elm]

did you read the tutorial?

[wispy haven]

I skimmed through, cause im on my phone now, i must have missed it

[ember elm]

that's not the point of tutorials..