Question [OSRS] How to use the Shop API?

I'm trying to make a bot that buys stuff from a shop, then switches worlds once it's done, then a few other things. I'll worry about the rest later, right now I'm stuck at buying things.

I figured out how to get the InterfaceComponent that I need using:

Code (Text):

1. InterfaceComponent itemInterface = Interfaces.newQuery().names("Item Name").results().first();

once I make sure that the shop's interface is open.

The problem with that is I have no idea how to get the stock of the item. I've gone through as much of the API as I think is applicable and I couldn't find anything except the Shop class. However, when I do anything with it, even just a simple

Code (Text):

1. if (Shop.isOpen()) { //doStuff }

I get either an ArrayIndexOutOfBounds or NullPointer exception.

I just started trying to write bots for RuneMate today, so I'm pretty sure that I'm using this completely wrong. Anyone know what I'm screwing up on?

--- Double Post Merged, Dec 5, 2015, Original Post Date: Dec 3, 2015 ---

Nevermind, I took a look at the Shop class and found:

Code (Text):

1. public static boolean isOpen() {
2. return Environment.isRS3()?IIIIiIiIiIII.class():iIIiiIiiiIii.do();
3. }

so I'm assuming the Shop API is for RS3 only. Is there any way to get the stock of a shop item in OSRS?
EDIT: Wait, I'm an idiot that's an if/else thing. I take back what I said about it being RS3 only.

 

Alright. Is there any way to get the stock of an item in the shop? I'm not sure what to use or where that data is stored.