Why don't items feature a "scripts" tab?

Dark_Ansem

I noticed this while digging HotU. Having a script tab would allow us to "bake" unique item powers into the item, rather than having to rely on module properties.

Sherincall

The engine considers item events to be the events of the module itself. There's a few technical reasons for this that aren't very relevant. The important thing is that you can still have per-item scripts. The most common approach is what HotU introduced called Tag-based scripting. It's detailed here:
https://nwnlexicon.com/index.php/Grimlar_-_Introduction_To_Tag_Based_Scripting

Basically, the idea is to have one script per item (or one per-item, per-event), and then from the module's OnItemUsed and similar events fire off the correct script based on the tag of the used item. This achieves the exact same result as you'd have with per-item script tab, while keeping the resource usage reasonable.

Dark_Ansem

Sherincall said:

The engine considers item events to be the events of the module itself. There's a few technical reasons for this that aren't very relevant. The important thing is that you can still have per-item scripts. The most common approach is what HotU introduced called Tag-based scripting. It's detailed here:
https://nwnlexicon.com/index.php/Grimlar_-_Introduction_To_Tag_Based_Scripting

Basically, the idea is to have one script per item (or one per-item, per-event), and then from the module's OnItemUsed and similar events fire off the correct script based on the tag of the used item. This achieves the exact same result as you'd have with per-item script tab, while keeping the resource usage reasonable.

I didn't know about that. I guess that having a dedicated "script" tab would allow for easy porting of the item between modules...

squattingmonk

Not really. Even if the script was specified on the item, the other module would still have to have the script for the item to function.

Dark_Ansem

squattingmonk said:

Not really. Even if the script was specified on the item, the other module would still have to have the script for the item to function.

Wouldn't ERF exporting do that?

FinalStand

Tag based scripting works well for items, I like it more than separate events (for items at least). All your code for that item is in one file. Otherwise you would have like 8 files per item. Have 20 custom items and that is 160 scripts!

Dark_Ansem

FinalStand said:

Tag based scripting works well for items, I like it more than separate events (for items at least). All your code for that item is in one file. Otherwise you would have like 8 files per item. Have 20 custom items and that is 160 scripts!

I'm sorry, I don't follow the math. Please explain?

squattingmonk

The math's slightly off, but the statement is still solid. Tagbased scripts make use of the GetUserDefinedItemEventNumber() function to determine if they're being called from 7 different events:

1. OnActivateItem
   
2. OnAcquireItem
   
3. OnUnAcquireItem
   
4. OnPlayerEquipItem
   
5. OnPlayerUnEquipItem
   
6. OnHitCast
   
7. OnSpellCastAt
   

By having one script that handles all the events, you avoid having to have 7 different scripts per item in the module.