QSStrings.m

/**
 * QSStrings.m
 * 
 * Copyright (c) 2010 - 2011, Quasidea Development, LLC
 * For more information, please go to http://www.quasidea.com/
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#import "QSUtilities.h"
#import "GTMNSString+HTML.h"

static const char _base64EncodingTable[64] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static const short _base64DecodingTable[256] = {
	-2, -2, -2, -2, -2, -2, -2, -2, -2, -1, -1, -2, -1, -1, -2, -2,
	-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
	-1, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, 62, -2, -2, -2, 63,
	52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -2, -2, -2, -2, -2, -2,
	-2,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
	15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -2, -2, -2, -2, -2,
	-2, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
	41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -2, -2, -2, -2, -2,
	-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
	-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
	-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
	-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
	-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
	-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
	-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
	-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2
};

@implementation QSStrings

+ (NSString *)implodeObjectArray:(NSArray *)objArray WithSelector:(SEL)selSelector Glue:(NSString *)strGlue {
	NSInteger intCount = [objArray count];
	if (intCount == 0) return nil;

	NSMutableString * strToReturn = [[[NSMutableString alloc] initWithString:(NSString *)[[objArray objectAtIndex:0] performSelector:selSelector]] autorelease];
	for (NSInteger intIndex = 1; intIndex < intCount; intIndex++) {
		[strToReturn appendFormat:@"%@%@", strGlue, (NSString *)[[objArray objectAtIndex:intIndex] performSelector:selSelector]];
	}
	
	return [NSString stringWithString:strToReturn];
}

+ (NSString *)implodeArray:(NSArray *)strArray WithGlue:(NSString *)strGlue {
	NSInteger intCount = [strArray count];
	if (intCount == 0) return nil;

	NSMutableString * strToReturn = [[[NSMutableString alloc] initWithString:(NSString *)[strArray objectAtIndex:0]] autorelease];
	for (NSInteger intIndex = 1; intIndex < intCount; intIndex++) {
		[strToReturn appendFormat:@"%@%@", strGlue, (NSString *)[strArray objectAtIndex:intIndex]];
	}

	return [NSString stringWithString:strToReturn];
}

+ (NSString *)trimString:(NSString *)strString {
	return [strString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
}

+ (NSString *)htmlEntities:(NSString *)strString {
	if (strString == nil) return @"";
	return [strString gtm_stringByEscapingForHTML];
}

+ (NSString *)escapeForXml:(NSString *)strString {
	if (strString == nil) return @"";
	return [NSString stringWithFormat:@"<![CDATA[%@]]>",
			[strString stringByReplacingOccurrencesOfString:@"]]>" withString:@"]]]]><![CDATA[>"]];
}

+ (NSString *)xmlDateStringForDate:(NSDate *)dttDate {
	if (dttDate == nil) return @"";

	NSDateComponents * objComponents = [[NSCalendar currentCalendar] components:(NSHourCalendarUnit|NSMinuteCalendarUnit|NSSecondCalendarUnit)
																	   fromDate:dttDate];

	NSDateFormatter * objDateFormatter = [[[NSDateFormatter alloc] init] autorelease];

	if (([objComponents hour] == 0) &&
		([objComponents minute] == 0) &&
		([objComponents second] == 0)) {
		// Date Only
		[objDateFormatter setDateFormat:@"yyyy-MM-dd"];
	} else {
		// Date AND Time which must include timezone
		[objDateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss zzz"];
	}

	return [objDateFormatter stringFromDate:dttDate];
}


+ (NSString *)encodeBase64UrlWithBase64:(NSString *)strBase64 {
	// Switch a base64 encoded string into a "base 64 url" encoded string
	// all that really means is no "=" padding and switch "-" for "+" and "_" for "/"
	
	// This is not a "standard" per se, but it is a widely used variant.
	// See http://en.wikipedia.org/wiki/Base64#URL_applications for more information

	return [[[strBase64 stringByReplacingOccurrencesOfString:@"=" withString:@""]
			 stringByReplacingOccurrencesOfString:@"+" withString:@"-"]
			stringByReplacingOccurrencesOfString:@"/" withString:@"_"];
}

+ (NSString *)encodeBase64WithString:(NSString *)strData {
	return [QSStrings encodeBase64WithData:[strData dataUsingEncoding:NSUTF8StringEncoding]];
}

/*
 Base64 Functions ported from PHP's Core

 +----------------------------------------------------------------------+
 | PHP Version 5                                                        |
 +----------------------------------------------------------------------+
 | Copyright (c) 1997-2010 The PHP Group                                |
 +----------------------------------------------------------------------+
 | This source file is subject to version 3.01 of the PHP license,      |
 | that is bundled with this package in the file LICENSE, and is        |
 | available through the world-wide-web at the following url:           |
 | http://www.php.net/license/3_01.txt                                  |
 | If you did not receive a copy of the PHP license and are unable to   |
 | obtain it through the world-wide-web, please send a note to          |
 | license@php.net so we can mail you a copy immediately.               |
 +----------------------------------------------------------------------+
 | Author: Jim Winstead <jimw@php.net>                                  |
 +----------------------------------------------------------------------+
*/

+ (NSString *)encodeBase64WithData:(NSData *)objData {
	const unsigned char * objRawData = [objData bytes];
	char * objPointer;
	char * strResult;

	// Get the Raw Data length and ensure we actually have data
	int intLength = [objData length];
	if (intLength == 0) return nil;

	// Setup the String-based Result placeholder and pointer within that placeholder
	strResult = (char *)calloc(((intLength + 2) / 3) * 4, sizeof(char));
	objPointer = strResult;
	
	// Iterate through everything
	while (intLength > 2) { // keep going until we have less than 24 bits
		*objPointer++ = _base64EncodingTable[objRawData[0] >> 2];
		*objPointer++ = _base64EncodingTable[((objRawData[0] & 0x03) << 4) + (objRawData[1] >> 4)];
		*objPointer++ = _base64EncodingTable[((objRawData[1] & 0x0f) << 2) + (objRawData[2] >> 6)];
		*objPointer++ = _base64EncodingTable[objRawData[2] & 0x3f];
		
		// we just handled 3 octets (24 bits) of data
		objRawData += 3;
		intLength -= 3; 
	}

	// now deal with the tail end of things
	if (intLength != 0) {
		*objPointer++ = _base64EncodingTable[objRawData[0] >> 2];
		if (intLength > 1) {
			*objPointer++ = _base64EncodingTable[((objRawData[0] & 0x03) << 4) + (objRawData[1] >> 4)];
			*objPointer++ = _base64EncodingTable[(objRawData[1] & 0x0f) << 2];
			*objPointer++ = '=';
		} else {
			*objPointer++ = _base64EncodingTable[(objRawData[0] & 0x03) << 4];
			*objPointer++ = '=';
			*objPointer++ = '=';
		}
	}

	// Terminate the string-based result
	*objPointer = '\0';

	// Return the results as an NSString object
	return [NSString stringWithCString:strResult encoding:NSASCIIStringEncoding];
}

+ (NSData *)decodeBase64WithString:(NSString *)strBase64 {
	const char * objPointer = [strBase64 cStringUsingEncoding:NSASCIIStringEncoding];
	int intLength = strlen(objPointer);
	int intCurrent;
	int i = 0, j = 0, k;

	unsigned char * objResult;
	objResult = calloc(intLength, sizeof(char));

	// Run through the whole string, converting as we go
	while ( ((intCurrent = *objPointer++) != '\0') && (intLength-- > 0) ) {
		if (intCurrent == '=') {
			if (*objPointer != '=' && ((i % 4) == 1)) {// || (intLength > 0)) {
				// the padding character is invalid at this point -- so this entire string is invalid
				free(objResult);
				return nil;
			}
			continue;
		}

		intCurrent = _base64DecodingTable[intCurrent];
		if (intCurrent == -1) {
			// we're at a whitespace -- simply skip over
			continue;
		} else if (intCurrent == -2) {
			// we're at an invalid character
			free(objResult);
			return nil;
		}

		switch (i % 4) {
			case 0:
				objResult[j] = intCurrent << 2;
				break;

			case 1:
				objResult[j++] |= intCurrent >> 4;
				objResult[j] = (intCurrent & 0x0f) << 4;
				break;

			case 2:
				objResult[j++] |= intCurrent >>2;
				objResult[j] = (intCurrent & 0x03) << 6;
				break;

			case 3:
				objResult[j++] |= intCurrent;
				break;
		}
		i++;
	}

	// mop things up if we ended on a boundary
	k = j;
	if (intCurrent == '=') {
		switch (i % 4) {
			case 1:
				// Invalid state
				free(objResult);
				return nil;

			case 2:
				k++;
				// flow through
			case 3:
				objResult[k] = 0;
		}
	}

	// Cleanup and setup the return NSData
	NSData * objData = [[[NSData alloc] initWithBytes:objResult length:j] autorelease];
	free(objResult);
	return objData;
}

@end