Errata

Section should read -(Void) instead of (void)

#pragma mark Instance Methods

- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];

// Release any cached data, images, etc that aren't in use.
}

instead it reads

(void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];

// Release any cached data, images, etc that aren't in use.
}

first line is missing the - charactor

Note from the Author or Editor:
Fixed in the second edition.
See: http://shop.oreilly.com/product/0636920018490.do

To be conform to best practices of the "Event Handling Guide" (http://developer.apple.com/library/ios/#documentation/EventHandling/Conceptual/EventHandlingiPhoneOS/Introduction/Introduction.html#//apple_ref/doc/uid/TP40009541 ; page 30),
the class CustomView which is a subclass of UIView must not call the nextResponder method and it must implement the methods touchesBegan, touchesMoved and touchesCancelled (a null implementation)

Note from the Author or Editor:
Fixed in the second edition.
See http://shop.oreilly.com/product/0636920018490.do

I don't think you should be releasing the "cities" variable. The cities variable here is just pointing to the object, it does not "own" it (it didn't allocate it), so it shouldn't release it. To put it another way, the alloc/release counts do not balance for this object: the original alloc is on p.69, there is a release for it on p.70, and this alloc on p.73 is a second release for the same object.

Note from the Author or Editor:
Fixed in the second edition.
See http://shop.oreilly.com/product/0636920018490.do

The XPath wrappers are no longer located at:

http://cocoawithlove.googlepages.com/XPathQuery.zip

and can now be found at:

http://projectswithlove.com/projects/XPathQuery.zip

Note from the Author or Editor:
Fixed in the second edition.
See http://shop.oreilly.com/product/0636920018490.do

text reads "RoundRect Button (Push Me!) Touch down event." when it probably should read "RoundRect Button (Push Me!) Touch Up Inside event."

Note from the Author or Editor:
Fixed in the second edition.
See http://shop.oreilly.com/product/0636920018490.do

The caption for Figure 6-18 refers to "Connecting the addCity: received action", while the figure itself shows connecting the addPicture: received action.

Note from the Author or Editor:
Fixed in the second edition.
See http://shop.oreilly.com/product/0636920018490.do

In the last sentence, "the one line (return cities.count;)" should read "return [cities count];", as that's what we were directed to code in the first example on p. 74.

Note from the Author or Editor:
Fixed in the second edition.
See http://shop.oreilly.com/product/0636920018490.do

I should have mentioned that the Y = 37 should be Y = 35 as well.

Note from the Author or Editor:
Fixed in the second edition.
See http://shop.oreilly.com/product/0636920018490.do

Figure 5.19 on the page looks like the UIImageView is centered horizontally, which requires either X = 35 (instead of 25), or width = 270 (instead of 250). Since the images are 1000 x 750, a width of 250 (with the height of 188) has the same aspect ratio, so the X = 35 change would be the right one.

Note from the Author or Editor:
Fixed in the second edition.
See http://shop.oreilly.com/product/0636920018490.do

The last sentence refers to a navigation bar 'with the title "City Guide"'. In figure 5-14, the navigation bar reads "Root View Controller" (as does the window in Interface Builder on my Mac as I'm following the steps in the book).

Note from the Author or Editor:
Fixed in the second edition.
See http://shop.oreilly.com/product/0636920018490.do

The code example in the book uses San Francisco, but the samples on the web site, including especially the images, use New York.

Note from the Author or Editor:
Fixed in the second edition.
See http://shop.oreilly.com/product/0636920018490.do

It says:

"Note the navigation bar that appears at the top (with the title "City Guide")."

However, we haven't gotten that far yet :-) Instead it should read:

"Note the navigation bar that appears at the top (with the title "Root View Controller")."

Note from the Author or Editor:
Fixed in the second edition.
See http://shop.oreilly.com/product/0636920018490.do

The NSURLConnection object is leaking in the example as it is not being released in connectionDidFinishLoading and didFailWithError, but it was instantiated with an alloc so reference count is +1 and needs to be released.

Note from the Author or Editor:
Fixed in the second edition.
See http://shop.oreilly.com/product/0636920018490.do

The icon instance variable is defined as a UIImage in the code:

// Current Conditions
UIImage *icon;
NSString *temp;
NSString *humidity;
NSString *wind;
NSString *condition;

whereas it is actually an NSString and not converted into an icon in the forecast. The code should be:

// Current Conditions
NSString *icon;
NSString *temp;
NSString *humidity;
NSString *wind;
NSString *condition;

This will impact a few further parts such as the @property definition for icon (to an NSString).

The reason the code works despite the incorrect type being displayed is that where it is used in Forecast.m:

icon = [NSString stringWithFormat:@"http://www.google.com%@", [node objectForKey:key]];

The stringWithFormat method returns an id, so breaks the type safety.

Then when the icon is used in MainViewController there has always been a cast (which should have been unnecessary!):

NSURL *url = [NSURL URLWithString:(NSString *)forecast.iconPath];

Note from the Author or Editor:
Fixed in the second edition.
See http://shop.oreilly.com/product/0636920018490.do

first, initialize is missing some lines of text between
NSMutableDictionary *defaultsToRegister = ...
and
[defaults registerDefaults:defaultsToRegister];

the missing lines are:

for (NSDictionary *defaultSetting in preferences) {
NSString *key = [defaultSetting valueForKey:kPreferenceKeyKey];
NSString *value = [defaultSetting valueForKey:kPreferenceDefValueKey];
if ((key != nil) && (value != nil)) {
[defaultsToRegister setValue:value forKey:key];
}
}

second, at the very top of the function, after assigning the singleton to NSUserDefaults *defaults, a check should be made to see if defaults is empty. if there was a string value in the defaults, e.g., "kFirstNameKey", the test could be this:

if ([defaults stringForKey:kFirstNameKey] != nil) {
return;
}

Note from the Author or Editor:
Fixed in the second edition.
See http://shop.oreilly.com/product/0636920018490.do

In Xcode, Build and Analyze reports a potential memory leak for Reachability *reach. Should there be some release code somewhere?

Note from the Author or Editor:
Fixed in the second edition. See http://shop.oreilly.com/product/0636920018490.do

Yes there should. The Reachability object reach is explicitly retained,

Reachability *reach = [[Reachability reachabilityForInternetConnection] retain];

and thus should be released. The easiest place to do this is after releasing the UIAlertView object. So the the applicationDidFinishLaunching: method should read,

- (void)applicationDidFinishLaunching:(UIApplication *)application {

[window addSubview:viewController.view];
[window makeKeyAndVisible];

Reachability *reach = [[Reachability reachabilityForInternetConnection] retain];
NetworkStatus status = [reach currentReachabilityStatus];

UIAlertView *alert = [[UIAlertView alloc]
initWithTitle:@"Reachability"
message:[self stringFromStatus: status]
delegate:self
cancelButtonTitle:@"OK"
otherButtonTitles:nil];
[alert show];
[alert release];
[reach release];

}

The dealloc: method in the code example in the middle of the page should read,

- (void)dealloc {
[names release];
[urls release];
[super dealloc];
}

rather than,


- (void)dealloc {
[names dealloc];
[urls dealloc];
[super dealloc];
}

Note from the Author or Editor:
Fixed in the second edition.
See http://shop.oreilly.com/product/0636920018490.do

In the final code snippet on p180, which spans to p181, implementing the dealloc: method for the Weather application the code should read:

- (void)dealloc {
[loadingActivityIndicator release];
[nameLabel release];
[dateLabel release];
[nowImage release];
[nowTempLabel release];
[nowHumidityLabel release];
[nowWindLabel release];
[nowConditionLabel release];
[dayOneLabel release];
[dayOneImage release];
[dayOneTempLabel release];
[dayOneChanceLabel release];
[dayTwoLabel release];
[dayTwoImage release];
[dayTwoTempLabel release];
[dayTwoChanceLabel release];
[dayThreeLabel release];
[dayThreeImage release];
[dayThreeTempLabel release];
[dayThreeChanceLabel release];
[dayFourLabel release];
[dayFourImage release];
[dayFourTempLabel release];
[dayFourChanceLabel release];
[refreshButton release];
[forecast release];

[super dealloc];
}

instead of,

- (void)dealloc {
[loadingActivityIndicator dealloc];
[nameLabel dealloc];
[dateLabel dealloc];
[nowImage dealloc];
[nowTempLabel dealloc];
[nowHumidityLabel dealloc];
[nowWindLabel dealloc];
[nowConditionLabel dealloc];
[dayOneLabel dealloc];
[dayOneImage dealloc];
[dayOneTempLabel dealloc];
[dayOneChanceLabel dealloc];
[dayTwoLabel dealloc];
[dayTwoImage dealloc];
[dayTwoTempLabel dealloc];
[dayTwoChanceLabel dealloc];
[dayThreeLabel dealloc];
[dayThreeImage dealloc];
[dayThreeTempLabel dealloc];
[dayThreeChanceLabel dealloc];
[dayFourLabel dealloc];
[dayFourImage dealloc];
[dayFourTempLabel dealloc];
[dayFourChanceLabel dealloc];
[refreshButton dealloc];
[forecast dealloc];

[super dealloc];
}

substituting the calls to the dealloc: method for each of the instance variables with calls to the release: method.

Note from the Author or Editor:
Fixed in the second edition.
See http://shop.oreilly.com/product/0636920018490.do

The NSData variable is not correctly released in the readCitiesFromDatabaseWithPath: method . Add the line,

[cityData release];

after the lines

NSData *cityData = [[NSData alloc] initWithBytes:sqlite3_column_blob(compiledStatement, 3) length: sqlite3_column_bytes(compiledStatement, 3)];
UIImage *cityImage = [UIImage imageWithData:cityData];

to rectify this problem.

Note from the Author or Editor:
Fixed in the second edition.
See http://shop.oreilly.com/product/0636920018490.do

In the copyDatabaseToDocuments: method the filePath variable needs to be retained before it is returned. The following line should be added,

[filePath retain];

after the line,

NSString *filePath = [documentsPath stringByAppendingPathComponent:@"cities.sqlite"];

Note from the Author or Editor:
Fixed in the second edition.
See http://shop.oreilly.com/product/0636920018490.do

The line

if ( self == [super init] )

should read

if ( self = [super init] )

We want to assign, not test for equality.

Note from the Author or Editor:
Fixed in the second edition. See http://shop.oreilly.com/product/0636920018490.do

Confirmed. The init method from the CityController.m class quoted on p82 should read,

- (id)initWithIndexPath: (NSIndexPath *)indexPath {
if ( self = [super init] ) {
index = indexPath;
}
return self;
}

We're overriding the initialisation method of the super class. It?s important to call the [super init] method first to ensure that instance variables up the inheritance hierarchy are initialized in the proper order (from top to bottom). Also, if your initialize code fails, you need to return nil from the overriden init method.