CocoaDev


Overview:


NSURL only goes so far in providing you access to chunks of a URL. If you need more parsing (like the parameters and query string etc) you can use these methods written by Jerry Krinock. http://goo.gl/General/OeSCu


Related Topics:


[Topic]


The Header


// NSSTRING METHODS WRITTEN BY JERRY KRINOCK [jerry]-[ieee]-[org]

@interface General/NSString (General/URIQuery)

// General/NSString has a method for decoding percent escapes but none for encoding // So, here they are: - (General/NSString)encodePercentEscapesPerRFC2396 ; - (General/NSString)encodePercentEscapesStrictlyPerRFC2396 ; // Decodes any existing percent escapes which should not be encoded per RFC 2396 sec. 2.4.3 // Encodes any characters which should be encoded per RFC 2396 sec. 2.4.3. - (General/NSString)encodePercentEscapesPerRFC2396ButNot:(General/NSString)butNot butAlso:(General/NSString*)butAlso ;

// butNot and/or butAlso may be nil // I did an experiment to find out which ASCII characters are encoded, // by encoding a string with all the nonalphanumeric characters available on the // Macintosh keyboard, with and without the shift key down. There were fourteen: // ` # % ^ [ ] { } \ | " < > // You only see thirteen because the fourtheenth one is the space character, " ". // This agrees with the lists of "space" "delims" and "unwise" in by RFC 2396 sec. 2.4.3 // Also, I found that all of the non-ASCII characters available on the Macintosh // keyboard by using option or shift+option are also encoded. Some of these have // two bytes of unicode to encode, for example %C2%A4 for 0xC2A4

/*! @brief Returns a string of the form "key0=value0&key1=value1&...". All keys and values are percent-escape encoded

@details For compatibility with POST, does not prepend a "?" All keys and all values must be General/NSString objects @param The dictionary of keys and values to be encoded into the string / + stringWithQueryDictionary:(General/NSDictionary)dictionary ;

/ Not sure how this is different than -stringByReplacingPercentEscapesUsingEncoding: Performing test in implementation to see if I can use that instead of this. / - (General/NSString*)decodeAllPercentEscapes ;

/*! @brief Assuming that the receiver is a query string of key=value pairs, of the form "key0=value0&key1=value1&...", with keys and values percent-escape encoded per RFC 2396, returns a dictionary of the keys and values.

@details Supports both ampersand "&" and semicolon ";" to delimit key-value pairs. The latter is recommended here: http://www.w3.org/TR/1998/REC-html40-19980424/appendix/notes.html#h-B.2.2 / - (General/NSDictionary)queryDictionaryUsingEncoding:(General/NSStringEncoding)encoding ;

@end


The Code


import "General/NSString+General/URIQuery.h"

@implementation General/NSString (General/URIQuery)

General/CFStringRef decodedString = (General/CFStringRef)[self decodeAllPercentEscapes] ; // The above may return NULL if url contains invalid escape sequences like %E8me, %E8fe, %E800 or %E811, // because General/CFURLCreateStringByReplacingPercentEscapes() isn't smart enough to ignore them. General/CFStringRef recodedString = General/CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, decodedString, NULL, NULL, kCFStringEncodingUTF8); // And then, if decodedString is NULL, recodedString will be NULL too. // So, we recover from this rare but possible error by returning the original self // because it's "better than nothing". General/NSString answer = (recodedString != NULL) ? [(General/NSString)recodedString autorelease] : self ; // Note that if recodedString is NULL, we don't need to General/CFRelease() it. // Actually, General/CFRelease(NULL) causes a crash. That's kind of stupid, Apple. return answer ; }

return cfWay ; }

return [[[NSDictionary dictionaryWithDictionary:pairs] ; }

@end