Initialising array before it gets called by NSTableView - objective-c

Question

I'm having trouble getting an NStableview to populate. I've been working through examples and have been having some success using a test array to feed it. My only problem is that the file often crashes on running (sometimes it doesn't, it's temperamental) and I think I've whittled it down to it sometimes returning nothing for array count. I'm going to guess this is because the array is sometimes not fully loaded by the time it's called by the tableview controller. Any ideas how to solve this? Thanks in advance.
tableController.h:
#import <Cocoa/Cocoa.h>
NSArray *testArray;
#interface tableController : NSObject {
IBOutlet NSTableView *jobsTable;
}
#end
tableController.m:
#import "tableController.h"
#implementation tableController
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
testArray = [NSArray arrayWithObjects:#"foo",#"bar",#"baz",nil];
}
- (int)numberOfRowsInTableView:(NSTableView *)tableView
{
if ([testArray count] > 0) {
return [testArray count];
} else {
return 0;
}
}
- (id)tableView:(NSTableView *)tableView
objectValueForTableColumn:(NSTableColumn *)tableColumn
row:(int)row
{
if ([testArray count] > 0) {
return [testArray objectAtIndex:row];
} else {
return 0;
}
}
#end

Answer 1

I am pretty sure testArray could be an instance variable, and there is no need for a global variable.
If you do this you could use a custom getter for testArray which lazy loads the array.
like this:
- (NSArray *)testArray {
if (!testArray) {
testArray = [[NSArray alloc] initWithObjects:#"foo",#"bar",#"baz",nil];
}
return testArray;
}
and all your tableView datasource methods would use self.testArray instead of testArray
- (NSInteger)numberOfRowsInTableView:(NSTableView *)tableView {
return [self.testArray count];
}

Answer 2

Try using init instead of applicationDidFinishLaunching for initialization. According to the documentation of NSApplicationDelegate, applicationDidFinishLaunching is called "after the application has been launched and initialized", but the TableView may well try to fetch its entries from the two delegate methods before that method is called.
If you absolutely have to use applicationDidFinishLaunching, you will have to check if testArray != nil before you access it in your delegate methods.