NSCoding

Interface Builder 3.0 is a beautiful thing, but I had trouble creating a plugin that allowed me to drag and drop a simple object into a NIB. With views, it’s trivial, but I couldn’t figure out why my object wasn’t draggable, even though it appeared in my plugin.

The answer is the NSCoding protocol. Because objects have to be archived to and unarchived from the NIB, you have to implement NSCoding, even if the methods do nothing.

Hope this helps.