iWillApps

In many applications you may need to save settings and reload them at various points. A nice way to do this is using a plist (property list) file, and assigning objects to keys.

NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
NSString* docDir = [paths objectAtIndex:0];
NSString* file = [docDir stringByAppendingString:@"/settings.plist"];
// To get objects
NSString* errorDesc = nil;
NSPropertyListFormat format;
NSData* plistXML = [[NSFileManager defaultManager] contentsAtPath:file];
NSDictionary *temp = (NSDictionary*)[NSPropertyListSerialization propertyListFromData:plistXML mutabilityOption:NSPropertyListMutableContainersAndLeaves format:&format errorDescription:&errorDesc];
NSString* savedText = [temp objectForKey:@"Saved_Text"];
float savedFloat = [[temp objectForKey:@"Saved_Float"] floatValue];
int savedInt = [[temp objectForKey:@"Saved_Int"] intValue];
// To set objects
NSMutableDictionary* rootObj = [NSMutableDictionary dictionaryWithCapacity:1];
[rootObj setObject:savedText forKey:@"Saved_Text"];
[rootObj setObject:[[NSString alloc] initWithFormat:@"%f",savedFloat] forKey:@"Saved_Float"];
[rootObj setObject:[[NSString alloc] initWithFormat:@"%d",savedInt] forKey:@"Saved_Int"];
NSString* errorDesc;
NSData* plistData = [NSPropertyListSerialization dataFromPropertyList:rootObj format:NSPropertyListXMLFormat_v1_0 errorDescription:&errorDesc];
if(plistData)
	[plistData writeToFile:file atomically:YES];

It also very good practice to store the settings file in the documents directory, lest it be overwritten by an update in the resources directory.