Encode NSString for XML/HTML
There isn't an NSString method that does that. You'll have to write your own function that does string replacements. It is sufficient to do the following replacements:
- '&' => "&"
- '"' => """
- '\'' => "'"
- '>' => ">"
- '<' => "<"
Something like this should do (haven't tried):
[[[[[myStr stringByReplacingOccurrencesOfString: @"&" withString: @"&"] stringByReplacingOccurrencesOfString: @"\"" withString: @"""] stringByReplacingOccurrencesOfString: @"'" withString: @"'"] stringByReplacingOccurrencesOfString: @">" withString: @">"] stringByReplacingOccurrencesOfString: @"<" withString: @"<"];
I took Mike's work and turn it into a category for NSMutableString and NSString
Make a Category for NSMutableString with:
- (NSMutableString *)xmlSimpleUnescape{ [self replaceOccurrencesOfString:@"&" withString:@"&" options:NSLiteralSearch range:NSMakeRange(0, [self length])]; [self replaceOccurrencesOfString:@""" withString:@"\"" options:NSLiteralSearch range:NSMakeRange(0, [self length])]; [self replaceOccurrencesOfString:@"'" withString:@"'" options:NSLiteralSearch range:NSMakeRange(0, [self length])]; [self replaceOccurrencesOfString:@"'" withString:@"'" options:NSLiteralSearch range:NSMakeRange(0, [self length])]; [self replaceOccurrencesOfString:@"’" withString:@"'" options:NSLiteralSearch range:NSMakeRange(0, [self length])]; [self replaceOccurrencesOfString:@"–" withString:@"-" options:NSLiteralSearch range:NSMakeRange(0, [self length])]; [self replaceOccurrencesOfString:@">" withString:@">" options:NSLiteralSearch range:NSMakeRange(0, [self length])]; [self replaceOccurrencesOfString:@"<" withString:@"<" options:NSLiteralSearch range:NSMakeRange(0, [self length])]; return self;}- (NSMutableString *)xmlSimpleEscape{ [self replaceOccurrencesOfString:@"&" withString:@"&" options:NSLiteralSearch range:NSMakeRange(0, [self length])]; [self replaceOccurrencesOfString:@"\"" withString:@""" options:NSLiteralSearch range:NSMakeRange(0, [self length])]; [self replaceOccurrencesOfString:@"'" withString:@"'" options:NSLiteralSearch range:NSMakeRange(0, [self length])]; [self replaceOccurrencesOfString:@">" withString:@">" options:NSLiteralSearch range:NSMakeRange(0, [self length])]; [self replaceOccurrencesOfString:@"<" withString:@"<" options:NSLiteralSearch range:NSMakeRange(0, [self length])]; return self;}Make a Category for NSString with:
- (NSString *)xmlSimpleUnescapeString{ NSMutableString *unescapeStr = [NSMutableString stringWithString:self]; return [unescapeStr xmlSimpleUnescape];}- (NSString *)xmlSimpleEscapeString{ NSMutableString *escapeStr = [NSMutableString stringWithString:self]; return [escapeStr xmlSimpleEscape];}* A Swift 2.0 Version *
The Objective-C version is a little more efficient as it does mutable operations on the string. However, this is a swift way to do simple escaping:
extension String{ typealias SimpleToFromRepalceList = [(fromSubString:String,toSubString:String)] // See http://stackoverflow.com/questions/24200888/any-way-to-replace-characters-on-swift-string // func simpleReplace( mapList:SimpleToFromRepalceList ) -> String { var string = self for (fromStr, toStr) in mapList { let separatedList = string.componentsSeparatedByString(fromStr) if separatedList.count > 1 { string = separatedList.joinWithSeparator(toStr) } } return string } func xmlSimpleUnescape() -> String { let mapList : SimpleToFromRepalceList = [ ("&", "&"), (""", "\""), ("'", "'"), ("'", "'"), ("’", "'"), ("–", "-"), (">", ">"), ("<", "<")] return self.simpleReplace(mapList) } func xmlSimpleEscape() -> String { let mapList : SimpleToFromRepalceList = [ ("&", "&"), ("\"", """), ("'", "'"), (">", ">"), ("<", "<")] return self.simpleReplace(mapList) }}I could have used the NSString bridging capabilities to write something very similar to the NSString version, but I decided to do it more swifty.
I use Google Toolbox for Mac (works on iPhone). In particular, see the additions to NSString in GTMNSString+HTML.h and GTMNSString+XML.h.