Lazy Initializer Never Called When Loading plist data into UITableView - iphone

Question

I'm trying to load a simple plist file (with an array at the root) into a UITableView (in the first view of an XCode 4.2 tabbed app). I've done this before in other (XCode 3) projects but for some reason it seems my lazy initializer for the array is never getting called.
.h file:
#import <UIKit/UIKit.h>
#interface NailPolishFirstViewController : UIViewController {
NSMutableArray *myCollection;
}
#property(nonatomic, retain) NSMutableArray *myCollection;
#end
.m file (relevant parts)
#import "NailPolishFirstViewController.h"
#implementation NailPolishFirstViewController
#synthesize myCollection;
// ...
- (NSMutableArray *) myCollection {
if (myCollection == nil) {
NSString *path = [[NSBundle mainBundle] bundlePath];
NSString *finalPath = [path stringByAppendingPathComponent:#"database.plist"];
self.myCollection = [NSMutableArray arrayWithContentsOfFile:finalPath];
NSLog(#"Collection size: %#", [self.myCollection count]);
}
return myCollection;
}
// ...
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
NSLog(#"Getting rows ... %#", [myCollection count]);
return [myCollection count];
}
// ...
The xib file for this controller has a UITableView attached and the dataSource and delegate are set to File's Owner.
When I build and run, the numberOfRowsInSection is logging "Getting rows ... (null)" but the log in my lazy initializer for myCollection never shows. Why isn't it ever getting called?

Answer 1

You aren't going through the accessor. Using [myCollection count] is accessing the ivar directly, which will be nil. If you're going to use lazy loading you have to always go via self.myCollection otherwise it will never call your accessor, and never populate the records.

Answer 2

Since myCollection is a declared property, it needs to reference its accessor. Try calling it as self.myCollection.
For instance
- (NSMutableArray *) myCollection {
if (myCollection == nil) {
NSString *path = [[NSBundle mainBundle] bundlePath];
NSString *finalPath = [path stringByAppendingPathComponent:#"database.plist"];
myCollection = [NSMutableArray arrayWithContentsOfFile:finalPath];
NSLog(#"Collection size: %#", [self.myCollection count]);
}
return myCollection;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
NSLog(#"Getting rows ... %#", [self.myCollection count]);
return [self.myCollection count];
}