Is it possible to call a method from the instantiating class?

Question

I have a class that is derived of UITableViewController and handles everything related with a specific type of tables. Let's call it Class T

In may main application class, Class A, I have methods to populate other areas of the screen as, for instance, a map.

While I'm populating my table within Class T, I would like to call the Class A method that plots the x,y points on the map.

Is this possible? What should be the correct way to do this?

When I though about this approach, I was expecting that invoking [super ...] inside Class T would call the Class A methods, as this is the owner class of the instance, but ofcourse it call the parent class, in my case the UITableViewController.

Thank you,
Pedro

Answer 1

If A is your main application class, you should be able to access the application instance with [UIApplication sharedApplication], cast it to the class A type, and call the APIs you need to call.

Answer 2

Why not define a ClassAProtocol and then add a property "classADelegate" in Class T? ClassAProtocol will define a method like:

-(void)plotXYOnMapFromData:(id)someObjectContainingDataToPlot;

So in the Class T interface you will add:

@property (assign) id classADelegate;

and then when you instantiate, let's say from instanceA (instance of Class A), instanceT (instance of Class T) you will do:

instanceT.classADelegate = instanceA;

Finally inside Class T you can call the plotting method in this way:

[classADelegate plotXYOnMapFromData:myDataToPlot];

The advantage of the delegate pattern in this case is that Class T just need to know only one small piece of ClassA, which is the protocol, and ClassA is able to communicate with T thanks to its implementation of the protocol.