NSStringAdditions.m

#import "NSStringAdditions.h"

@implementation NSString (NSStringAdditions)

+ (NSString *)stringByGeneratingUUID {
    CFUUIDRef UUIDReference = CFUUIDCreate(nil);
    CFStringRef temporaryUUIDString = CFUUIDCreateString(nil, UUIDReference);
    
    CFRelease(UUIDReference);
#if ! __has_feature(objc_arc)
    return [NSMakeCollectable(temporaryUUIDString) autorelease];
#else
    return (__bridge_transfer NSString*)temporaryUUIDString;
#endif
}

#pragma mark -

- (NSString *)unescapedString {
    NSMutableString *string = [NSMutableString stringWithString: self];
    
    [string replaceOccurrencesOfString: @"&"  withString: @"&" options: NSLiteralSearch range: NSMakeRange(0, [string length])];
    [string replaceOccurrencesOfString: @""" withString: @"\"" options: NSLiteralSearch range: NSMakeRange(0, [string length])];
    [string replaceOccurrencesOfString: @"'" withString: @"'" options: NSLiteralSearch range: NSMakeRange(0, [string length])];
    [string replaceOccurrencesOfString: @"9" withString: @"'" options: NSLiteralSearch range: NSMakeRange(0, [string length])];
    [string replaceOccurrencesOfString: @"’" withString: @"'" options: NSLiteralSearch range: NSMakeRange(0, [string length])];
    [string replaceOccurrencesOfString: @"–" withString: @"'" options: NSLiteralSearch range: NSMakeRange(0, [string length])];
    [string replaceOccurrencesOfString: @">" withString: @">" options: NSLiteralSearch range: NSMakeRange(0, [string length])];
    [string replaceOccurrencesOfString: @"&lt;" withString: @"<" options: NSLiteralSearch range: NSMakeRange(0, [string length])];
    
    return [NSString stringWithString: string];
}

- (NSString *)escapedString {
    NSMutableString *string = [NSMutableString stringWithString: self];
    
    // NOTE: we use unicode entities instead of &amp; &gt; &lt; etc. since some hosts (powweb, fatcow, and similar)
    // have a weird PHP/libxml2 combination that ignores regular entities
    [string replaceOccurrencesOfString: @"&"  withString: @"&#38;" options: NSLiteralSearch range: NSMakeRange(0, [string length])];
    [string replaceOccurrencesOfString: @">"  withString: @"&#62;" options: NSLiteralSearch range: NSMakeRange(0, [string length])];
    [string replaceOccurrencesOfString: @"<"  withString: @"&#60;" options: NSLiteralSearch range: NSMakeRange(0, [string length])];
    
    return [NSString stringWithString: string];
}

@end