New answer for the edited new question:
It appears that the mixup is with calling the asynch service. I'll give two kinds of advice here. First, the simplest possible table-containing view controller that gets its data from an asynch service, and second, a little class that wraps the parse asynch service. First the VC:
// in a vc with a table view .m
@interface MyViewController ()
@property(weak,nonatomic) IBOutlet UITableView *tableView;
@property(strong,nonatomic) NSArray *array; // this class keeps the array
@end
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
[ClassThatHandlesMyQuery doQuery:^(NSArray *results) {
self.array = results;
[self.tableView reloadData];
}];
}
See how the query class method in the other class takes a block parameter? This is required because the query happens asynchronously.
// do the normal table view stuff
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return self.array.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
PFObject *pfObject = self.array[indexPath.row];
cell.textLabel.text = [pfObject valueForKey:@"someStringProperty"];
return cell;
}
That should be pretty much all you need in the vc. Now let's look at your query method. It makes three mistakes: (a) No block parameter to let the caller get the asynch result, (b) it mishandles the array in the query completion block, (c) at the end of the method, it wrongly supposes that a variable _savedTankArray is initialized, in the block. That code appears below the block, but it actually runs before the block runs.\
Let's fix all three problems. First declare a public method:
// ClassThatHandlesMyQuery.h
+ (void) doQuery:(void (^)(NSArray *))completion;
See how it takes a block as param? Now implement:
// ClassThatHandlesMyQuery.m
+ (void) doQuery:(void (^)(NSArray *))completion {
// your query code. let's assume this is fine
PFUser *userName = [PFUser currentUser];
NSString *userNameString = [userName objectForKey:@"username"];
PFQuery *query = [[PFQuery alloc] initWithClassName:@"SavedTanks"];
[query whereKey:@"userName" equalTo:userNameString];
[query setValue:@"SavedTanks" forKeyPath:@"parseClassName"];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
// the job is MUCH simpler here than your code supposed.
// log the result for fun
NSLog(@"did we get objects? %@", objects);
// hand it back to the caller
// notice there's no array kept in this class. it's not needed
// and it would be awkward to do it at the class (not instance) level
completion(objects);
} else {
NSLog(@"bad news from parse: %@", error);
completion(nil);
}
}
// this is important
NSLog(@"hi mom!");
// watch your log output. 'hi mom' will appear before either message
// from the block. why is that? because that block runs later
// after the network request completes. but the hi mom NSLog runs
// just before the network request starts. this is why it's wrong to expect
// any variable set in the block to be initialized here
}
Believe it or not, that's it. You should be able to write exactly the mini view controller class and the mini query classes as described here, and see data from parse in a UITableView. I suggest you build something just like this (exactly like this) first just to get going