New at modding DS, need help with crafting

[callmeP]

Hi, i'm trying to mod Ds for the first time, i'm sorry for these stupid questions.

I studied most of the scripts file of the game but i can't really find that start the crafting function, not the build but the one that "calls" the builder.lua. Also, i was wondering HOW the game sees the different elements of the ui declared through the xml file in the <element> tag.