This method will mimic javascript function "encodeURIComponent(<string to be encoded>)" in Objective C

URICoder

+ (NSString *) encodeString: (NSString *) string {
	
	NSMutableString *output = [NSMutableString string];
	const unsigned char *source = (const unsigned char *)[string UTF8String];
	int sourceLen = (int)strlen((const char *)source);
	for (int i = 0; i < sourceLen; ++i) {
		const unsigned char thisChar = source[i];
		if (thisChar == ' '){
			[output appendString:@"%20"];
		} else if (thisChar == '.' || thisChar == '-' || thisChar == '_' || thisChar == '~' ||
				   (thisChar >= 'a' && thisChar <= 'z') ||
				   (thisChar >= 'A' && thisChar <= 'Z') ||
				   (thisChar >= '0' && thisChar <= '9')) {
			[output appendFormat:@"%c", thisChar];
		} else {
			[output appendFormat:@"%%%02X", thisChar];
		}
	}
	return output;
}