Question

I have a bit of an architecture problem. I have a method that returns an array based on data from a server.

NSArray *myStuff = [anObject getMyStuff];

Obviously the server can fail. What is the best way to cater for this? I was looking at how performFetch: works, but that has a BOOL as a return type. Can I have:

NSArray *myStuff = [anObject getMyStuff:&anError];

Answer 1

You should, as e.James suggested before, do a proper asynchronous handling, where the object, that performs the fetch, will call a method, if it was successful or another, if it failed.
There is an variant of this, that is used in the popular AFNetworking: pass two blocks to the method, one for the failing case, one for the success case

This could look like this than:

[client shopsFeedForUserWithID:2 
                       success:^(id response) {
                           blockSelf.shops = [Shop shopsFromReponseDict:response];
                           [blockSelf.tableView reloadData];
                      } failure:^(NSError *error) {
                           //handle the error
                      }];