Tag Archives: Cocoa

underretain in CoreAnimation / iPhone Simulator

After upgrading to Snow Leopard and XCode 3.2.1 I’ve seen such console output CAUnderRetain(32139,0xa0391500) malloc: *** error for object 0x3838000: pointer being freed was not allocated *** set a breakpoint in malloc_error_break to debug when rotating the iPhone Simulator in a project with base SDK 3.0. This can be reproduced as follows: Create a fresh […]

CoreData generic findManyByKey

The base for many of my SELECT-ish queries when querying by exact match is one generic method I created in some category methods on NSManagedObjectContext: -(NSArray*)entityName:(NSString*)entityName findManyByRelation:(NSDictionary*)dict { // TODO handle dict nil and emptyness NSMutableArray *arr = [[NSMutableArray alloc] initWithCapacity:dict.count]; for(NSString *key in dict) { NSExpression *left = [NSExpression expressionForKeyPath:key]; NSExpression *right = [NSExpression […]

NSDateFormatter case sensitive trap

Though NSDateFormatter behaves slightly different than documented, the following might even be correct, as strange as it might look (mind the last two lines): -(void)testNSDateFormatterTrap { NSDateFormatter *lower = [[[NSDateFormatter alloc] init] autorelease]; lower.dateFormat = @"yyyy-MM-dd HH:mm:SS ZZZ";   NSDateFormatter *upper = [[[NSDateFormatter alloc] init] autorelease]; upper.dateFormat = @"YYYY-MM-dd HH:mm:SS ZZZ";   lower.timeZone = upper.timeZone […]

CocoaTouch, CoreData and binary String Search

The query optimiser for NSPredicate queries ontop CoreData/SQLite on the iPhone is a bit rudimentary (cough) and so I had to optimise myself to get binary-search enabled quick results:

Cocoa wrapped regex.h

Strange enough there’s no regular expression class in the iPhone SDK. Update: iOS 4 brings NSRegularExpression. My simple wrapper around the regex.h C API is not safe for unicode matching patterns but does the job e.g. for parsing URLs. If you need more, have a look at RegexKitLite. My simple wrapper has the interface:

NSDateFormatter & Http Header

A.S. Update 2, License: as I’ve been asked about which license this code is under: I put this into Public Domain. No warranty whatsoever. Still I’d be happy about attribution but don’t require such. Ever tried to get e.g. the „Last-Modified“ HTTP response header field into a NSDate object? That’s no real fun, because this […]

NSURLCache Joke / iPhone

Did you ever wonder why Apple’s own Demo App URLCache doesn’t use the NSURLCache class, but rather reimplements disk caching instead? Well, it looks like NSURLCache promises disk-caching, but doesn’t keep this promise.

NSURLConnection gzip magic

For quite some time I ranted about not being able to use compressed network communcation out-of-the-box on the iPhone. Despite being undocumented (or I just overlooked the hint), NSURLConnection does gzip decompression transparently! That’s how to use it: