Reasons for an IBOutlet to be nil

Question

What are the reasons why an IBOutlet (connected) could be nil?

I have one in may application which is always nil, even if I re

Answer 1

One possibility: Suppose the IBOutlet container is a singleton object with a function like:

+ (singletonObject*) sharedInstance {
    if(!gGlobalSingletonPointer) {
        gGlobalSingletonPointer = [[singletonObject alloc] init];
    }

    return gGlobalSingletonPointer;
}

You create the singleton object "on demand" if it doesn't already exist. You save a global pointer to it, as you create it, in that function.

If you also instantiate such an object in InterfaceBuilder, and connect its outlets, this object will be created without sharedInstance being called. If you subsequently call sharedInstance, a new object is created (sans IBOutlet connections).

The solution is to update the global pointer in singletonObject's init or awakeFromNib function.