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mwaterfall/gist:953664

Created May 3, 2011 16:28
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  1. mwaterfall created this gist May 3, 2011.
    146 changes: 146 additions & 0 deletions gistfile1.m
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    Original file line number Diff line number Diff line change
    @@ -0,0 +1,146 @@
    //
    // NSDate+InternetDateTime.h
    // MWFeedParser
    //
    // Created by Michael Waterfall on 07/10/2010.
    // Copyright 2010 Michael Waterfall. All rights reserved.
    //

    #import <Foundation/Foundation.h>

    // Date format hints for parsing date from internet string
    typedef enum {DateFormatHintNone, DateFormatHintRFC822, DateFormatHintRFC3339} DateFormatHint;

    @interface NSDate (InternetDateTime)
    + (NSDate *)dateFromInternetDateTimeString:(NSString *)dateString formatHint:(DateFormatHint)hint;
    + (NSDate *)dateFromRFC3339String:(NSString *)dateString;
    + (NSDate *)dateFromRFC822String:(NSString *)dateString;
    @end

    //
    // NSDate+InternetDateTime.m
    // MWFeedParser
    //
    // Created by Michael Waterfall on 07/10/2010.
    // Copyright 2010 Michael Waterfall. All rights reserved.
    //

    #import "NSDate+InternetDateTime.h"

    @implementation NSDate (InternetDateTime)

    // Good info on internet dates here: http://developer.apple.com/iphone/library/qa/qa2010/qa1480.html

    // Get a date from a string - hit (from specs) can be used to speed up
    + (NSDate *)dateFromInternetDateTimeString:(NSString *)dateString formatHint:(DateFormatHint)hint {
    NSDate *date = nil;
    if (hint != DateFormatHintRFC3339) {
    // Try RFC822 first
    date = [NSDate dateFromRFC822String:dateString];
    if (!date) date = [NSDate dateFromRFC3339String:dateString];
    } else {
    // Try RFC3339 first
    date = [NSDate dateFromRFC3339String:dateString];
    if (!date) date = [NSDate dateFromRFC822String:dateString];
    }
    return date;
    }

    // See http://www.faqs.org/rfcs/rfc822.html
    + (NSDate *)dateFromRFC822String:(NSString *)dateString {

    // Create date formatter
    static NSDateFormatter *dateFormatter = nil;
    if (!dateFormatter) {
    NSLocale *en_US_POSIX = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"];
    dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setLocale:en_US_POSIX];
    [dateFormatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];
    [en_US_POSIX release];
    }

    // Process
    NSDate *date = nil;
    NSString *RFC822String = [[NSString stringWithString:dateString] uppercaseString];
    if ([RFC822String rangeOfString:@","].location != NSNotFound) {
    if (!date) { // Sun, 19 May 2002 15:21:36 GMT
    [dateFormatter setDateFormat:@"EEE, d MMM yyyy HH:mm:ss zzz"];
    date = [dateFormatter dateFromString:RFC822String];
    }
    if (!date) { // Sun, 19 May 2002 15:21 GMT
    [dateFormatter setDateFormat:@"EEE, d MMM yyyy HH:mm zzz"];
    date = [dateFormatter dateFromString:RFC822String];
    }
    if (!date) { // Sun, 19 May 2002 15:21:36
    [dateFormatter setDateFormat:@"EEE, d MMM yyyy HH:mm:ss"];
    date = [dateFormatter dateFromString:RFC822String];
    }
    if (!date) { // Sun, 19 May 2002 15:21
    [dateFormatter setDateFormat:@"EEE, d MMM yyyy HH:mm"];
    date = [dateFormatter dateFromString:RFC822String];
    }
    } else {
    if (!date) { // 19 May 2002 15:21:36 GMT
    [dateFormatter setDateFormat:@"d MMM yyyy HH:mm:ss zzz"];
    date = [dateFormatter dateFromString:RFC822String];
    }
    if (!date) { // 19 May 2002 15:21 GMT
    [dateFormatter setDateFormat:@"d MMM yyyy HH:mm zzz"];
    date = [dateFormatter dateFromString:RFC822String];
    }
    if (!date) { // 19 May 2002 15:21:36
    [dateFormatter setDateFormat:@"d MMM yyyy HH:mm:ss"];
    date = [dateFormatter dateFromString:RFC822String];
    }
    if (!date) { // 19 May 2002 15:21
    [dateFormatter setDateFormat:@"d MMM yyyy HH:mm"];
    date = [dateFormatter dateFromString:RFC822String];
    }
    }
    if (!date) NSLog(@"Could not parse RFC822 date: \"%@\" Possibly invalid format.", dateString);
    return date;

    }

    // See http://www.faqs.org/rfcs/rfc3339.html
    + (NSDate *)dateFromRFC3339String:(NSString *)dateString {

    // Create date formatter
    static NSDateFormatter *dateFormatter = nil;
    if (!dateFormatter) {
    NSLocale *en_US_POSIX = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"];
    dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setLocale:en_US_POSIX];
    [dateFormatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];
    [en_US_POSIX release];
    }

    // Process date
    NSDate *date = nil;
    NSString *RFC3339String = [[NSString stringWithString:dateString] uppercaseString];
    RFC3339String = [RFC3339String stringByReplacingOccurrencesOfString:@"Z" withString:@"-0000"];
    // Remove colon in timezone as iOS 4+ NSDateFormatter breaks. See https://devforums.apple.com/thread/45837
    if (RFC3339String.length > 20) {
    RFC3339String = [RFC3339String stringByReplacingOccurrencesOfString:@":"
    withString:@""
    options:0
    range:NSMakeRange(20, RFC3339String.length-20)];
    }
    if (!date) { // 1996-12-19T16:39:57-0800
    [dateFormatter setDateFormat:@"yyyy'-'MM'-'dd'T'HH':'mm':'ssZZZ"];
    date = [dateFormatter dateFromString:RFC3339String];
    }
    if (!date) { // 1937-01-01T12:00:27.87+0020
    [dateFormatter setDateFormat:@"yyyy'-'MM'-'dd'T'HH':'mm':'ss.SSSZZZ"];
    date = [dateFormatter dateFromString:RFC3339String];
    }
    if (!date) { // 1937-01-01T12:00:27
    [dateFormatter setDateFormat:@"yyyy'-'MM'-'dd'T'HH':'mm':'ss"];
    date = [dateFormatter dateFromString:RFC3339String];
    }
    if (!date) NSLog(@"Could not parse RFC3339 date: \"%@\" Possibly invalid format.", dateString);
    return date;

    }

    @end