onUseItem bug

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AdrTru
Posts: 223
Joined: Sat Jan 19, 2013 10:10 pm
Location: Trutnov, Czech Republic

onUseItem bug

Post by AdrTru » Sun Jan 25, 2015 2:49 am

I have problem with detect onUseItem situation.
If I addConnector to item.usableitem it look like good but after using item program made this error:
Image

For way around this problem I try use FW hook. If I create import "mod_assets/scripts/clone_object.lua" as JKos wrote and add

Code: Select all

   modifyObjects{
       filter = {
			hasComponents = {"item","usableitem"},
       },
       components = {
			fw_addHooks{
			class = 'UsableItem',
			},
       }
    }
all touched object lost its standard onUseItem features (are only consumed ).

What I must do for managing onUseItem event when I want to define it from script during running game for its correct working?
thx.
Last edited by AdrTru on Sat Feb 07, 2015 5:22 pm, edited 1 time in total.
My LOG2 projects: virtual money, Forge recipes, liquid potions and
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Eleven Warrior
Posts: 725
Joined: Thu Apr 18, 2013 2:32 pm
Location: Australia

Re: onUseIem bug

Post by Eleven Warrior » Sun Jan 25, 2015 9:51 am

Hi ArdTru you may need to post a pm to Jkos or Minmay for help mate :)

minmay
Posts: 2654
Joined: Mon Sep 23, 2013 2:24 am

Re: onUseIem bug

Post by minmay » Sun Jan 25, 2015 10:33 am

When a connector is triggered, it checks the component's parent's map in some way. I don't know why it does this, but it does. This means that a connector triggering on a component belonging to an object that is not on a map - such as an item in a champion's inventory, on the mouse, or inside a container - will cause the Lua error you discovered.
If you want to use connectors on items, the easiest way is definitely to use the scripting framework. But be careful about function ownership. In particular, you should only reference the global environment (and any arguments you receive) in your hook functions.
This is because saving/reloading with a function that is referenced from multiple places can change the environment of the function. For example I created a test dungeon with two script entities named "cow" and "goat". I placed "goat" to the northwest of "cow". Here is the source for "cow":

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ANIMAL = "Cow"

function test()
	print(ANIMAL)
end
And the source for "goat":

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ANIMAL = "Goat"

dtest = cow.script.test
Now if I export this dungeon, start the game, and try calling both function references:

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cow.script.test()
Cow
goat.script.test()
Cow
We can see that both fields have cow.script as their local environment.
But if I save and reload the dungeon, then try the test again:

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cow.script.test()
Goat
goat.script.test()
Goat
Now both fields have goat.script as their local environment! If you're ever going to hold references to a function outside of the script that defines it, don't try to use the local environment. It will absolutely bite you in the ass.

On the other hand, this is really useful if you want to detect when the player reloads the game!
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