Friday, May 10, 2013

NSDateFormatter NSDateFormatterShortStyle example ios

NSDateFormatterStyle - NSDateFormatterShortStyle

The following constants specify predefined format styles for dates and times.
typedef enum {
   NSDateFormatterNoStyle     = kCFDateFormatterNoStyle,
   NSDateFormatterShortStyle  = kCFDateFormatterShortStyle,
   NSDateFormatterMediumStyle = kCFDateFormatterMediumStyle,
   NSDateFormatterLongStyle   = kCFDateFormatterLongStyle,
   NSDateFormatterFullStyle   = kCFDateFormatterFullStyle
} NSDateFormatterStyle;
Specifies no style.
Specifies a short style, typically numeric only, such as “11/23/37” or “3:30pm”.
Specifies a medium style, typically with abbreviated text, such as “Nov 23, 1937”.
Specifies a long style, typically with full text, such as “November 23, 1937” or “3:30:32pm”.
Specifies a full style with complete details, such as “Tuesday, April 12, 1952 AD” or “3:30:42pm PST”.
The format for these date and time styles is not exact because they depend on the locale, user preference settings, and the operating system version. Do not use these constants if you want an exact format.
Example of [NSDateFormatter NSDateFormatterShortStyle]
NSString *theTime = @"3:19 PM"; 
NSDateFormatter *timeFormatter = [[[NSDateFormatter alloc] init] autorelease];       
[timeFormatter setTimeStyle:NSDateFormatterShortStyle]; 
[timeFormatter setDateStyle:NSDateFormatterNoStyle]; 
NSDate *date = [timeFormatter dateFromString:theTime]; 
NSString *theString = [timeFormatter stringFromDate:date]; 
Example of [NSDateFormatter NSDateFormatterShortStyle]
- (NSString*) humanRelativeDateAndTimeAlt: (NSDate*) date;

NSDateFormatter* relativeDateFormatter = [[NSDateFormatter alloc] init];
[relativeDateFormatter setLocale: [NSLocale autoupdatingCurrentLocale]];
[relativeDateFormatter setTimeStyle:NSDateFormatterNoStyle]; // no time for this formatter
[relativeDateFormatter setDateStyle:NSDateFormatterMediumStyle];
[dateFormatter setDoesRelativeDateFormatting:YES]; // relative dates

NSString* datePart = [[self relativeDateFormatter] stringFromDate:date];

NSDateFormatter* timeDateFormatter = [[NSDateFormatter alloc] init];
[timeDateFormatter setLocale:[NSLocale autoupdatingCurrentLocale]];
[timeDateFormatter setDateStyle: NSDateFormatterNoStyle]; // no date for this formatter
[timeDateFormatter setTimeStyle: NSDateFormatterShortStyle]; // does respect 12/24 hour setting

NSString* timePart = [timeDateFormatter stringFromDate:date];

int skipZero = 0;  // extra code to remove leading zero if present 
if ([[timePart substringToIndex:1] isEqualToString:@"0"]) skipZero = 1;

[relativeDateFormater release];
[timeDateFormatter release];

return [NSString stringWithFormat:@"%@ %@", datePart, [timePart substringFromIndex:skipZero]];
Example of [NSDateFormatter NSDateFormatterShortStyle]
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setLocale:[NSLocale currentLocale]];
[formatter setDateStyle:NSDateFormatterNoStyle];
[formatter setTimeStyle:NSDateFormatterShortStyle];
NSString *dateString = [formatter stringFromDate:[NSDate date]];
NSRange amRange = [dateString rangeOfString:[formatter AMSymbol]];
NSRange pmRange = [dateString rangeOfString:[formatter PMSymbol]];
BOOL is24h = (amRange.location == NSNotFound && pmRange.location == NSNotFound);
[formatter release];
NSLog(@"%@\n",(is24h ? @"YES" : @"NO"));