This document contains various snippets of technical advice and best practices for iOS development. The snippets discuss topics such as debugging with DebugLog, image loading techniques, memory management, networking, scrolling performance, resource management, CoreData and SQLite usage, and enumeration. Each snippet is attributed to Citrrus LLC and copyrighted in 2012.

1. © 2012 Citrrus LLC. All Rights Reserved.

2. The iPhone will prove to be more historically
significant than
the Personal Computer
© 2012 Citrrus LLC. All Rights Reserved.

3. Above a Bar
© 2012 Citrrus LLC. All Rights Reserved.

4. Agile Optimization
Start slow...
© 2012 Citrrus LLC. All Rights Reserved.

5. DebugLog... your best friend
#ifdef DEBUG
#define DebugLog(...) NSLog(@"%s (%d) %@",
__PRETTY_FUNCTION__, __LINE__, [NSString
stringWithFormat:__VA_ARGS__])
#else
#define DebugLog(...)
#endif
2012-05-07 18:02:20.775 UVA Magazine[4509:17c03]
-[PDFPageViewController viewWillAppear:] (78) View Will Appear for PDF Page
© 2012 Citrrus LLC. All Rights Reserved.

6. Perception
“Beauty is everywhere a
welcome guest.”
Johann Wolfgang von Goethe
© 2012 Citrrus LLC. All Rights Reserved.

7. Images... more than meets the eye
+[UIImage imageNamed:]
* Reads file
* Uncompresses
* Caches
+[UIImage imageWithContentsOfFile:]
* Checks access to file
* File is read and uncompressed
when image drawn
© 2012 Citrrus LLC. All Rights Reserved.

8. Images... more than meets the eye
© 2012 Citrrus LLC. All Rights Reserved.

9. Memory Management
Use Less
Release Early and Often
© 2012 Citrrus LLC. All Rights Reserved.

10. Networking
Combine Requests
Compact your data
© 2012 Citrrus LLC. All Rights Reserved.

11. Fast Scrolling
Do your own drawing
Reuse/Recycle
Don’t get in the way of the
main thread
© 2012 Citrrus LLC. All Rights Reserved.

12. Burn the resource you have
Memory vs CPU
© 2012 Citrrus LLC. All Rights Reserved.

13. CoreData + SQLite
CoreData + SQLite = partial file access
-[NSData initWithContentsOfFile] = full file access
© 2012 Citrrus LLC. All Rights Reserved.

14. Enumeration
objectAtIndex
for(int i=0;i<count;i++)
{
id item;
item = [myObjects objectAtIndex:i];
NSLog(@"Found an Item: %@",item);
}
NSFastEnumeration
for(id item in myObjects)
{
NSLog@"Found an Item: %@",item);
}
© 2012 Citrrus LLC. All Rights Reserved.