mods/atsocial_iphone_app/TouchJSON/JSON/CJSONScanner.m

   1 //
   2 //  CJSONScanner.m
   3 //  TouchJSON
   4 //
   5 //  Created by Jonathan Wight on 12/07/2005.
   6 //  Copyright 2005 Toxic Software. All rights reserved.
   7 //
   8
   9 #import "CJSONScanner.h"
  10
  11 #import "NSCharacterSet_Extensions.h"
  12 #import "CDataScanner_Extensions.h"
  13
  14 inline static int HexToInt(char inCharacter)
  15 {
  16 int theValues[] = { 0x0 /* 48 '0' */, 0x1 /* 49 '1' */, 0x2 /* 50 '2' */, 0x3 /* 51 '3' */, 0x4 /* 52 '4' */, 0x5 /* 53 '5' */, 0x6 /* 54 '6' */, 0x7 /* 55 '7' */, 0x8 /* 56 '8' */, 0x9 /* 57 '9' */, -1 /* 58 ':' */, -1 /* 59 ';' */, -1 /* 60 '<' */, -1 /* 61 '=' */, -1 /* 62 '>' */, -1 /* 63 '?' */, -1 /* 64 '@' */, 0xa /* 65 'A' */, 0xb /* 66 'B' */, 0xc /* 67 'C' */, 0xd /* 68 'D' */, 0xe /* 69 'E' */, 0xf /* 70 'F' */, -1 /* 71 'G' */, -1 /* 72 'H' */, -1 /* 73 'I' */, -1 /* 74 'J' */, -1 /* 75 'K' */, -1 /* 76 'L' */, -1 /* 77 'M' */, -1 /* 78 'N' */, -1 /* 79 'O' */, -1 /* 80 'P' */, -1 /* 81 'Q' */, -1 /* 82 'R' */, -1 /* 83 'S' */, -1 /* 84 'T' */, -1 /* 85 'U' */, -1 /* 86 'V' */, -1 /* 87 'W' */, -1 /* 88 'X' */, -1 /* 89 'Y' */, -1 /* 90 'Z' */, -1 /* 91 '[' */, -1 /* 92 '\' */, -1 /* 93 ']' */, -1 /* 94 '^' */, -1 /* 95 '_' */, -1 /* 96 '`' */, 0xa /* 97 'a' */, 0xb /* 98 'b' */, 0xc /* 99 'c' */, 0xd /* 100 'd' */, 0xe /* 101 'e' */, 0xf /* 102 'f' */, };
  17 if (inCharacter >= '0' && inCharacter <= 'f')
  18         return(theValues[inCharacter - '0']);
  19 else
  20         return(-1);
  21 }
  22
  23 @interface CJSONScanner ()
  24 @property (readwrite, retain) NSCharacterSet *notQuoteCharacters;
  25 @property (readwrite, retain) NSCharacterSet *whitespaceCharacterSet;
  26 @end
  27
  28 #pragma mark -
  29
  30 @implementation CJSONScanner
  31
  32 @synthesize scanComments;
  33 @synthesize notQuoteCharacters;
  34 @synthesize whitespaceCharacterSet;
  35
  36 - (id)init
  37 {
  38 if ((self = [super init]) != nil)
  39         {
  40         self.notQuoteCharacters = [[NSCharacterSet characterSetWithCharactersInString:@"\\\""] invertedSet];
  41         self.whitespaceCharacterSet = [NSCharacterSet whitespaceAndNewlineCharacterSet];
  42         }
  43 return(self);
  44 }
  45
  46 - (void)dealloc
  47 {
  48 self.notQuoteCharacters = NULL;
  49 self.whitespaceCharacterSet = NULL;
  50 //
  51 [super dealloc];
  52 }
  53
  54 #pragma mark -
  55
  56 - (void)setData:(NSData *)inData
  57 {
  58 NSData *theData = inData;
  59 if (theData && theData.length >= 4)
  60         {
  61         // This code is lame, but it works. Because the first character of any JSON string will always be a control character we can work out the Unicode encoding by the bit pattern. See section 3 of http://www.ietf.org/rfc/rfc4627.txt
  62         const char *theChars = theData.bytes;
  63         NSStringEncoding theEncoding = NSUTF8StringEncoding;
  64         if (theChars[0] != 0 && theChars[1] == 0)
  65                 {
  66                 if (theChars[2] != 0 && theChars[3] == 0)
  67                         theEncoding = NSUTF16LittleEndianStringEncoding;
  68                 else if (theChars[2] == 0 && theChars[3] == 0)
  69                         theEncoding = NSUTF32LittleEndianStringEncoding;
  70                 }
  71         else if (theChars[0] == 0 && theChars[2] == 0 && theChars[3] != 0)
  72                 {
  73                 if (theChars[1] == 0)
  74                         theEncoding = NSUTF32BigEndianStringEncoding;
  75                 else if (theChars[1] != 0)
  76                         theEncoding = NSUTF16BigEndianStringEncoding;
  77                 }
  78
  79         if (theEncoding != NSUTF8StringEncoding)
  80                 {
  81                 NSString *theString = [[[NSString alloc] initWithData:theData encoding:theEncoding] autorelease];
  82                 theData = [theString dataUsingEncoding:NSUTF8StringEncoding];
  83                 }
  84         }
  85 [super setData:theData];
  86 }
  87
  88 #pragma mark -
  89
  90 - (BOOL)scanJSONObject:(id *)outObject error:(NSError **)outError
  91 {
  92 [self skipJSONWhitespace];
  93
  94 id theObject = NULL;
  95
  96 const unichar C = [self currentCharacter];
  97 switch (C)
  98         {
  99         case 't':
 100                 if ([self scanUTF8String:"true" intoString:NULL])
 101                         {
 102                         theObject = [NSNumber numberWithBool:YES];
 103                         }
 104                 break;
 105         case 'f':
 106                 if ([self scanUTF8String:"false" intoString:NULL])
 107                         {
 108                         theObject = [NSNumber numberWithBool:NO];
 109                         }
 110                 break;
 111         case 'n':
 112                 if ([self scanUTF8String:"null" intoString:NULL])
 113                         {
 114                         theObject = [NSNull null];
 115                         }
 116                 break;
 117         case '\"':
 118         case '\'':
 119                 [self scanJSONStringConstant:&theObject error:outError];
 120                 break;
 121         case '0':
 122         case '1':
 123         case '2':
 124         case '3':
 125         case '4':
 126         case '5':
 127         case '6':
 128         case '7':
 129         case '8':
 130         case '9':
 131         case '-':
 132                 [self scanJSONNumberConstant:&theObject error:outError];
 133                 break;
 134         case '{':
 135                 [self scanJSONDictionary:&theObject error:outError];
 136                 break;
 137         case '[':
 138                 [self scanJSONArray:&theObject error:outError];
 139                 break;
 140         default:
 141
 142                 break;
 143         }
 144
 145 if (outObject != NULL)
 146         *outObject = theObject;
 147 return(YES);
 148 }
 149
 150 - (BOOL)scanJSONDictionary:(NSDictionary **)outDictionary error:(NSError **)outError
 151 {
 152 unsigned theScanLocation = [self scanLocation];
 153
 154 //[self skipJSONWhitespace];
 155
 156 if ([self scanCharacter:'{'] == NO)
 157         {
 158         if (outError)
 159                 {
 160                 *outError = [NSError errorWithDomain:@"CJSONScannerErrorDomain" code:-1 userInfo:NULL];
 161                 }
 162         return(NO);
 163         }
 164
 165 NSMutableDictionary *theDictionary = [NSMutableDictionary dictionary];
 166
 167 while ([self scanCharacter:'}'] == NO)
 168         {
 169         NSString *theKey = NULL;
 170         if ([self scanJSONStringConstant:&theKey error:outError] == NO)
 171                 {
 172                 [self setScanLocation:theScanLocation];
 173                 if (outError)
 174                         {
 175                         *outError = [NSError errorWithDomain:@"CJSONScannerErrorDomain" code:-2 userInfo:NULL];
 176                         }
 177                 return(NO);
 178                 }
 179
 180         [self skipJSONWhitespace];
 181
 182         if ([self scanCharacter:':'] == NO)
 183                 {
 184                 [self setScanLocation:theScanLocation];
 185                 if (outError)
 186                         {
 187                         *outError = [NSError errorWithDomain:@"CJSONScannerErrorDomain" code:-3 userInfo:NULL];
 188                         }
 189                 return(NO);
 190                 }
 191
 192         id theValue = NULL;
 193         if ([self scanJSONObject:&theValue error:outError] == NO)
 194                 {
 195                 [self setScanLocation:theScanLocation];
 196                 if (outError)
 197                         {
 198                         *outError = [NSError errorWithDomain:@"CJSONScannerErrorDomain" code:-4 userInfo:NULL];
 199                         }
 200                 return(NO);
 201                 }
 202
 203         [theDictionary setValue:theValue forKey:theKey];
 204
 205         [self skipJSONWhitespace];
 206         if ([self scanCharacter:','] == NO)
 207                 {
 208                 if ([self currentCharacter] != '}')
 209                         {
 210                         [self setScanLocation:theScanLocation];
 211                         if (outError)
 212                                 {
 213                                 *outError = [NSError errorWithDomain:@"CJSONScannerErrorDomain" code:-5 userInfo:NULL];
 214                                 }
 215                         return(NO);
 216                         }
 217                 break;
 218                 }
 219         else
 220                 {
 221                 [self skipJSONWhitespace];
 222                 if ([self currentCharacter] == '}')
 223                         break;
 224                 }
 225         }
 226
 227 if ([self scanCharacter:'}'] == NO)
 228         {
 229         [self setScanLocation:theScanLocation];
 230         if (outError)
 231                 {
 232                 *outError = [NSError errorWithDomain:@"CJSONScannerErrorDomain" code:-6 userInfo:NULL];
 233                 }
 234         return(NO);
 235         }
 236
 237 if (outDictionary != NULL)
 238         *outDictionary = theDictionary;
 239 return(YES);
 240 }
 241
 242 - (BOOL)scanJSONArray:(NSArray **)outArray error:(NSError **)outError
 243 {
 244 unsigned theScanLocation = [self scanLocation];
 245
 246 //[self skipJSONWhitespace];
 247 if ([self scanCharacter:'['] == NO)
 248         {
 249         if (outError)
 250                 {
 251                 *outError = [NSError errorWithDomain:@"CJSONScannerErrorDomain" code:-7 userInfo:NULL];
 252                 }
 253         return(NO);
 254         }
 255
 256 NSMutableArray *theArray = [NSMutableArray array];
 257
 258 [self skipJSONWhitespace];
 259 while ([self currentCharacter] != ']')
 260         {
 261         NSString *theValue = NULL;
 262         if ([self scanJSONObject:&theValue error:outError] == NO)
 263                 {
 264                 [self setScanLocation:theScanLocation];
 265                 if (outError)
 266                         {
 267                         *outError = [NSError errorWithDomain:@"CJSONScannerErrorDomain" code:-8 userInfo:NULL];
 268                         }
 269                 return(NO);
 270                 }
 271
 272         [theArray addObject:theValue];
 273
 274         [self skipJSONWhitespace];
 275         if ([self scanCharacter:','] == NO)
 276                 {
 277                 [self skipJSONWhitespace];
 278                 if ([self currentCharacter] != ']')
 279                         {
 280                         [self setScanLocation:theScanLocation];
 281                         if (outError)
 282                                 {
 283                                 *outError = [NSError errorWithDomain:@"CJSONScannerErrorDomain" code:-9 userInfo:NULL];
 284                                 }
 285                         return(NO);
 286                         }
 287
 288                 break;
 289                 }
 290         [self skipJSONWhitespace];
 291         }
 292
 293 [self skipJSONWhitespace];
 294
 295 if ([self scanCharacter:']'] == NO)
 296         {
 297         [self setScanLocation:theScanLocation];
 298         if (outError)
 299                 {
 300                 *outError = [NSError errorWithDomain:@"CJSONScannerErrorDomain" code:-10 userInfo:NULL];
 301                 }
 302         return(NO);
 303         }
 304
 305 if (outArray != NULL)
 306         *outArray = theArray;
 307 return(YES);
 308 }
 309
 310 - (BOOL)scanJSONStringConstant:(NSString **)outStringConstant error:(NSError **)outError
 311 {
 312 unsigned theScanLocation = [self scanLocation];
 313
 314 [self skipJSONWhitespace]; //  TODO - i want to remove this method. But breaks unit tests.
 315
 316 NSMutableString *theString = [NSMutableString string];
 317
 318 if ([self scanCharacter:'"'] == NO)
 319         {
 320         [self setScanLocation:theScanLocation];
 321         if (outError)
 322                 {
 323                 *outError = [NSError errorWithDomain:@"CJSONScannerErrorDomain" code:-11 userInfo:NULL];
 324                 }
 325         return(NO);
 326         }
 327
 328 while ([self scanCharacter:'"'] == NO)
 329         {
 330         NSString *theStringChunk = NULL;
 331         if ([self scanCharactersFromSet:notQuoteCharacters intoString:&theStringChunk])
 332                 {
 333                 [theString appendString:theStringChunk];
 334                 }
 335
 336         if ([self scanCharacter:'\\'] == YES)
 337                 {
 338                 unichar theCharacter = [self scanCharacter];
 339                 switch (theCharacter)
 340                         {
 341                         case '"':
 342                         case '\\':
 343                         case '/':
 344                                 break;
 345                         case 'b':
 346                                 theCharacter = '\b';
 347                                 break;
 348                         case 'f':
 349                                 theCharacter = '\f';
 350                                 break;
 351                         case 'n':
 352                                 theCharacter = '\n';
 353                                 break;
 354                         case 'r':
 355                                 theCharacter = '\r';
 356                                 break;
 357                         case 't':
 358                                 theCharacter = '\t';
 359                                 break;
 360                         case 'u':
 361                                 {
 362                                 theCharacter = 0;
 363
 364                                 int theShift;
 365                                 for (theShift = 12; theShift >= 0; theShift -= 4)
 366                                         {
 367                                         const int theDigit = HexToInt([self scanCharacter]);
 368                                         if (theDigit == -1)
 369                                                 {
 370                                                 [self setScanLocation:theScanLocation];
 371                                                 if (outError)
 372                                                         {
 373                                                         *outError = [NSError errorWithDomain:@"CJSONScannerErrorDomain" code:-12 userInfo:NULL];
 374                                                         }
 375                                                 return(NO);
 376                                                 }
 377                                         theCharacter |= (theDigit << theShift);
 378                                         }
 379                                 }
 380                                 break;
 381                         default:
 382                                 {
 383                                 [self setScanLocation:theScanLocation];
 384                                 if (outError)
 385                                         {
 386                                         *outError = [NSError errorWithDomain:@"CJSONScannerErrorDomain" code:-13 userInfo:NULL];
 387                                         }
 388                                 return(NO);
 389                                 }
 390                                 break;
 391                         }
 392                 CFStringAppendCharacters((CFMutableStringRef)theString, &theCharacter, 1);
 393 //              [theString appendFormat:@"%C", theCharacter];
 394                 }
 395         }
 396
 397 if (outStringConstant != NULL)
 398         *outStringConstant = theString;
 399
 400 return(YES);
 401 }
 402
 403 - (BOOL)scanJSONNumberConstant:(NSNumber **)outNumberConstant error:(NSError **)outError
 404 {
 405 //[self skipJSONWhitespace];
 406
 407 NSNumber *theNumber = NULL;
 408 if ([self scanNumber:&theNumber] == YES)
 409         {
 410         if (outNumberConstant != NULL)
 411                 *outNumberConstant = theNumber;
 412         return(YES);
 413         }
 414 else
 415         {
 416         if (outError)
 417                 {
 418                 *outError = [NSError errorWithDomain:@"CJSONScannerErrorDomain" code:-14 userInfo:NULL];
 419                 }
 420         return(NO);
 421         }
 422 }
 423
 424 - (void)skipJSONWhitespace
 425 {
 426 [self scanCharactersFromSet:whitespaceCharacterSet intoString:NULL];
 427 if (scanComments)
 428         {
 429         [self scanCStyleComment:NULL];
 430         [self scanCPlusPlusStyleComment:NULL];
 431         [self scanCharactersFromSet:whitespaceCharacterSet intoString:NULL];
 432         }
 433 }
 434
 435 @end