I will attempt to list down small tricks&tips which might help you keep your code clean and save lot of debugging time. Some of these are ofcourse extracted from other posts else where :-)
1. When using an NSURLConnection, as a rule you may well want to implement the delegate method:
I find most web calls are very singular and it's more the exception than the rule you'll be wanting responses cached, especially for web service calls. Implementing the method as shown disables caching of responses.
2. Set your properties as nonatomic. They're atomic by default and upon synthesis, semaphore code will be created to prevent multi-threading problems. 99% of you probably don't need to worry about this and the code is much less bloated and memory efficient when set to nonatomic.
3. Don't use unknown strings as format strings When methods or functions take a format string argument, you should make sure that you have control over the content of the format string. For example, when logging strings, it is tempting to pass the string variable as the sole argument to NSLog:
NSString *aString = // get a string from somewhere;
NSLog(aString);
The problem with this is that the string may contain characters that are interpreted as format strings. This can lead to erroneous output, crashes, and security problems. Instead, you should substitute the string variable into a format string:
NSLog(@"aString: %@", aString);
4. This is subtle one but handy one. If you're passing yourself as a delegate to another object, reset that object's delegate before you dealloc.
By doing this you're ensuring that no more delegate methods will get sent. As you're about to dealloc and disappear into the ether you want to make sure that nothing can send you any more messages by accident. Remember self.someObject could be retained by another object (it could be a singleton or on the autorelease pool or whatever) and until you tell it "stop sending me messages!", it thinks your just-about-to-be-dealloced object is fair game.Getting into this habit will save you from lots of weird crashes that are a pain to debug.The same principal applies to Key Value Observation, and NSNotifications too.
5. Use #pragma mark [section]. Usually I group by my own methods, each subclass's overrides, and any information or formal protocols. This makes it a lot easier to jump to exactly what I'm looking for. On the same topic, group similar methods (like a table view's delegate methods) together, don't just stick them anywhere.
6. Clean up in dealloc. This is one of the easiest things to forget - esp. when coding at 150mph. Always, always, always clean up your attributes/member variables in dealloc.
1. When using an NSURLConnection, as a rule you may well want to implement the delegate method:
- (NSCachedURLResponse *)connection:(NSURLConnection *)connection willCacheResponse:(NSCachedURLResponse *)cachedResponse
{
return nil;
}
I find most web calls are very singular and it's more the exception than the rule you'll be wanting responses cached, especially for web service calls. Implementing the method as shown disables caching of responses.
2. Set your properties as nonatomic. They're atomic by default and upon synthesis, semaphore code will be created to prevent multi-threading problems. 99% of you probably don't need to worry about this and the code is much less bloated and memory efficient when set to nonatomic.
3. Don't use unknown strings as format strings When methods or functions take a format string argument, you should make sure that you have control over the content of the format string. For example, when logging strings, it is tempting to pass the string variable as the sole argument to NSLog:
NSString *aString = // get a string from somewhere;
NSLog(aString);
The problem with this is that the string may contain characters that are interpreted as format strings. This can lead to erroneous output, crashes, and security problems. Instead, you should substitute the string variable into a format string:
NSLog(@"aString: %@", aString);
4. This is subtle one but handy one. If you're passing yourself as a delegate to another object, reset that object's delegate before you dealloc.
- (void)dealloc { self.someObject.delegate = NULL; self.someObject = NULL; // [super dealloc]; }
By doing this you're ensuring that no more delegate methods will get sent. As you're about to dealloc and disappear into the ether you want to make sure that nothing can send you any more messages by accident. Remember self.someObject could be retained by another object (it could be a singleton or on the autorelease pool or whatever) and until you tell it "stop sending me messages!", it thinks your just-about-to-be-dealloced object is fair game.Getting into this habit will save you from lots of weird crashes that are a pain to debug.The same principal applies to Key Value Observation, and NSNotifications too.
5. Use #pragma mark [section]. Usually I group by my own methods, each subclass's overrides, and any information or formal protocols. This makes it a lot easier to jump to exactly what I'm looking for. On the same topic, group similar methods (like a table view's delegate methods) together, don't just stick them anywhere.
6. Clean up in dealloc. This is one of the easiest things to forget - esp. when coding at 150mph. Always, always, always clean up your attributes/member variables in dealloc.
