Empty quickbar slot evaluates to valid invalid LuaItemStack

[sparr]

My quickbar is empty.

game.player.get_inventory(defines.inventory.player_quickbar)[1].valid is true
game.player.get_inventory(defines.inventory.player_quickbar)[1].name produces "Error: LuaItemStack API call when LuaItemStack was invalid"...

[Klonan]

My quickbar is empty.

game.player.get_inventory(defines.inventory.player_quickbar)[1].valid is true
game.player.get_inventory(defines.inventory.player_quickbar)[1].name produces "Error: LuaItemStack API call when LuaItemStack was invalid"...

The ItemStack was valid, as the object exists,
But it was not valud for read, which is what you should check before trying to read from it:

http://lua-api.factorio.com/latest/LuaI ... d_for_read

Is this valid for reading? Differs from the usual valid in that valid will be true even if the item stack is blank but the entity that holds it is still valid.

[sparr]

Thanks!

To be clear, is checking valid_for_read the only way to find out if a specific inventory slot is empty?

[Nexela]

That is correct

slot is valid if it is a slot, slot is valid_for_read if it has something in it.

[sparr]

maybe in the error message replace "invalid" with "not valid_for_read"?