iOS In-app purchase question

[Danneman101]

I've found a good tutorial on how to set up in-app purchase.

But how do you in code check to see if a certain product has been bought in the in-app purchase-store? I mean, what is the syntax that corresponds to the pseudocode below:

if (product1_isBought == true)
   enable product1-stuff
else
   disable product1-stuff

 

[dejo]

When a product is purchased, what I do is set a value in NSUserDefaults to flag this and then simply check the value out of NSUserDefaults when needed.