FLEXRuntimeUtility.m 28 KB

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  1. //
  2. // FLEXRuntimeUtility.m
  3. // Flipboard
  4. //
  5. // Created by Ryan Olson on 6/8/14.
  6. // Copyright (c) 2014 Flipboard. All rights reserved.
  7. //
  8. #import "FLEXRuntimeUtility.h"
  9. // See https://developer.apple.com/library/ios/documentation/Cocoa/Conceptual/ObjCRuntimeGuide/Articles/ocrtPropertyIntrospection.html#//apple_ref/doc/uid/TP40008048-CH101-SW6
  10. NSString *const kFLEXUtilityAttributeTypeEncoding = @"T";
  11. NSString *const kFLEXUtilityAttributeBackingIvar = @"V";
  12. NSString *const kFLEXUtilityAttributeReadOnly = @"R";
  13. NSString *const kFLEXUtilityAttributeCopy = @"C";
  14. NSString *const kFLEXUtilityAttributeRetain = @"&";
  15. NSString *const kFLEXUtilityAttributeNonAtomic = @"N";
  16. NSString *const kFLEXUtilityAttributeCustomGetter = @"G";
  17. NSString *const kFLEXUtilityAttributeCustomSetter = @"S";
  18. NSString *const kFLEXUtilityAttributeDynamic = @"D";
  19. NSString *const kFLEXUtilityAttributeWeak = @"W";
  20. NSString *const kFLEXUtilityAttributeGarbageCollectable = @"P";
  21. NSString *const kFLEXUtilityAttributeOldStyleTypeEncoding = @"t";
  22. static NSString *const FLEXRuntimeUtilityErrorDomain = @"FLEXRuntimeUtilityErrorDomain";
  23. typedef NS_ENUM(NSInteger, FLEXRuntimeUtilityErrorCode) {
  24. FLEXRuntimeUtilityErrorCodeDoesNotRecognizeSelector = 0,
  25. FLEXRuntimeUtilityErrorCodeInvocationFailed = 1,
  26. FLEXRuntimeUtilityErrorCodeArgumentTypeMismatch = 2
  27. };
  28. // Arguments 0 and 1 are self and _cmd always
  29. const unsigned int kFLEXNumberOfImplicitArgs = 2;
  30. @implementation FLEXRuntimeUtility
  31. #pragma mark - Property Helpers (Public)
  32. + (NSString *)prettyNameForProperty:(objc_property_t)property
  33. {
  34. NSString *name = @(property_getName(property));
  35. NSString *encoding = [self typeEncodingForProperty:property];
  36. NSString *readableType = [self readableTypeForEncoding:encoding];
  37. return [self appendName:name toType:readableType];
  38. }
  39. + (NSString *)typeEncodingForProperty:(objc_property_t)property
  40. {
  41. NSDictionary *attributesDictionary = [self attributesDictionaryForProperty:property];
  42. return [attributesDictionary objectForKey:kFLEXUtilityAttributeTypeEncoding];
  43. }
  44. + (BOOL)isReadonlyProperty:(objc_property_t)property
  45. {
  46. return [[self attributesDictionaryForProperty:property] objectForKey:kFLEXUtilityAttributeReadOnly] != nil;
  47. }
  48. + (SEL)setterSelectorForProperty:(objc_property_t)property
  49. {
  50. SEL setterSelector = NULL;
  51. NSString *setterSelectorString = [[self attributesDictionaryForProperty:property] objectForKey:kFLEXUtilityAttributeCustomSetter];
  52. if (!setterSelectorString) {
  53. NSString *propertyName = @(property_getName(property));
  54. setterSelectorString = [NSString stringWithFormat:@"set%@%@:", [[propertyName substringToIndex:1] uppercaseString], [propertyName substringFromIndex:1]];
  55. }
  56. if (setterSelectorString) {
  57. setterSelector = NSSelectorFromString(setterSelectorString);
  58. }
  59. return setterSelector;
  60. }
  61. + (NSString *)fullDescriptionForProperty:(objc_property_t)property
  62. {
  63. NSDictionary *attributesDictionary = [self attributesDictionaryForProperty:property];
  64. NSMutableArray *attributesStrings = [NSMutableArray array];
  65. // Atomicity
  66. if ([attributesDictionary objectForKey:kFLEXUtilityAttributeNonAtomic]) {
  67. [attributesStrings addObject:@"nonatomic"];
  68. } else {
  69. [attributesStrings addObject:@"atomic"];
  70. }
  71. // Storage
  72. if ([attributesDictionary objectForKey:kFLEXUtilityAttributeRetain]) {
  73. [attributesStrings addObject:@"strong"];
  74. } else if ([attributesDictionary objectForKey:kFLEXUtilityAttributeCopy]) {
  75. [attributesStrings addObject:@"copy"];
  76. } else if ([attributesDictionary objectForKey:kFLEXUtilityAttributeWeak]) {
  77. [attributesStrings addObject:@"weak"];
  78. } else {
  79. [attributesStrings addObject:@"assign"];
  80. }
  81. // Mutability
  82. if ([attributesDictionary objectForKey:kFLEXUtilityAttributeReadOnly]) {
  83. [attributesStrings addObject:@"readonly"];
  84. } else {
  85. [attributesStrings addObject:@"readwrite"];
  86. }
  87. // Custom getter/setter
  88. NSString *customGetter = [attributesDictionary objectForKey:kFLEXUtilityAttributeCustomGetter];
  89. NSString *customSetter = [attributesDictionary objectForKey:kFLEXUtilityAttributeCustomSetter];
  90. if (customGetter) {
  91. [attributesStrings addObject:[NSString stringWithFormat:@"getter=%@", customGetter]];
  92. }
  93. if (customSetter) {
  94. [attributesStrings addObject:[NSString stringWithFormat:@"setter=%@", customSetter]];
  95. }
  96. NSString *attributesString = [attributesStrings componentsJoinedByString:@", "];
  97. NSString *shortName = [self prettyNameForProperty:property];
  98. return [NSString stringWithFormat:@"@property (%@) %@", attributesString, shortName];
  99. }
  100. + (id)valueForProperty:(objc_property_t)property onObject:(id)object
  101. {
  102. NSString *customGetterString = nil;
  103. char *customGetterName = property_copyAttributeValue(property, "G");
  104. if (customGetterName) {
  105. customGetterString = @(customGetterName);
  106. free(customGetterName);
  107. }
  108. SEL getterSelector;
  109. if ([customGetterString length] > 0) {
  110. getterSelector = NSSelectorFromString(customGetterString);
  111. } else {
  112. NSString *propertyName = @(property_getName(property));
  113. getterSelector = NSSelectorFromString(propertyName);
  114. }
  115. return [self performSelector:getterSelector onObject:object withArguments:nil error:NULL];
  116. }
  117. + (NSString *)descriptionForIvarOrPropertyValue:(id)value
  118. {
  119. NSString *description = nil;
  120. // Special case BOOL for better readability.
  121. if ([value isKindOfClass:[NSValue class]]) {
  122. const char *type = [value objCType];
  123. if (strcmp(type, @encode(BOOL)) == 0) {
  124. BOOL boolValue = NO;
  125. [value getValue:&boolValue];
  126. description = boolValue ? @"YES" : @"NO";
  127. }
  128. }
  129. if (!description) {
  130. // Single line display - replace newlines and tabs with spaces.
  131. description = [[value description] stringByReplacingOccurrencesOfString:@"\n" withString:@" "];
  132. description = [description stringByReplacingOccurrencesOfString:@"\t" withString:@" "];
  133. }
  134. if (!description) {
  135. description = @"nil";
  136. }
  137. return description;
  138. }
  139. + (void)tryAddPropertyWithName:(const char *)name attributes:(NSDictionary *)attributePairs toClass:(__unsafe_unretained Class)theClass
  140. {
  141. objc_property_t property = class_getProperty(theClass, name);
  142. if (!property) {
  143. unsigned int totalAttributesCount = [attributePairs count];
  144. objc_property_attribute_t *attributes = malloc(sizeof(objc_property_attribute_t) * totalAttributesCount);
  145. if (attributes) {
  146. unsigned int attributeIndex = 0;
  147. for (NSString *attributeName in [attributePairs allKeys]) {
  148. objc_property_attribute_t attribute;
  149. attribute.name = [attributeName UTF8String];
  150. attribute.value = [[attributePairs objectForKey:attributeName] UTF8String];
  151. attributes[attributeIndex++] = attribute;
  152. }
  153. class_addProperty(theClass, name, attributes, totalAttributesCount);
  154. free(attributes);
  155. }
  156. }
  157. }
  158. #pragma mark - Ivar Helpers (Public)
  159. + (NSString *)prettyNameForIvar:(Ivar)ivar
  160. {
  161. NSString *name = @(ivar_getName(ivar));
  162. NSString *encoding = @(ivar_getTypeEncoding(ivar));
  163. NSString *readableType = [self readableTypeForEncoding:encoding];
  164. return [self appendName:name toType:readableType];
  165. }
  166. + (id)valueForIvar:(Ivar)ivar onObject:(id)object
  167. {
  168. id value = nil;
  169. const char *type = ivar_getTypeEncoding(ivar);
  170. if (type[0] == @encode(id)[0] || type[0] == @encode(Class)[0]) {
  171. value = object_getIvar(object, ivar);
  172. } else {
  173. ptrdiff_t offset = ivar_getOffset(ivar);
  174. void *pointer = (__bridge void *)object + offset;
  175. value = [self valueForPrimitivePointer:pointer objCType:type];
  176. }
  177. return value;
  178. }
  179. + (void)setValue:(id)value forIvar:(Ivar)ivar onObject:(id)object
  180. {
  181. const char *typeEncodingCString = ivar_getTypeEncoding(ivar);
  182. if (typeEncodingCString[0] == '@') {
  183. object_setIvar(object, ivar, value);
  184. } else if ([value isKindOfClass:[NSValue class]]) {
  185. // Primitive - unbox the NSValue.
  186. NSValue *valueValue = (NSValue *)value;
  187. // Make sure that the box contained the correct type.
  188. NSAssert(strcmp([valueValue objCType], typeEncodingCString) == 0, @"Type encoding mismatch (value: %s; ivar: %s) in setting ivar named: %s on object: %@", [valueValue objCType], typeEncodingCString, ivar_getName(ivar), object);
  189. NSUInteger bufferSize = 0;
  190. @try {
  191. // NSGetSizeAndAlignment barfs on type encoding for bitfields.
  192. NSGetSizeAndAlignment(typeEncodingCString, &bufferSize, NULL);
  193. } @catch (NSException *exception) { }
  194. if (bufferSize > 0) {
  195. void *buffer = calloc(bufferSize, 1);
  196. [valueValue getValue:buffer];
  197. ptrdiff_t offset = ivar_getOffset(ivar);
  198. void *pointer = (__bridge void *)object + offset;
  199. memcpy(pointer, buffer, bufferSize);
  200. free(buffer);
  201. }
  202. }
  203. }
  204. #pragma mark - Method Helpers (Public)
  205. + (NSString *)prettyNameForMethod:(Method)method isClassMethod:(BOOL)isClassMethod
  206. {
  207. NSString *selectorName = NSStringFromSelector(method_getName(method));
  208. NSString *methodTypeString = isClassMethod ? @"+" : @"-";
  209. char *returnType = method_copyReturnType(method);
  210. NSString *readableReturnType = [self readableTypeForEncoding:@(returnType)];
  211. free(returnType);
  212. NSString *prettyName = [NSString stringWithFormat:@"%@ (%@)", methodTypeString, readableReturnType];
  213. NSArray *components = [self prettyArgumentComponentsForMethod:method];
  214. if ([components count] > 0) {
  215. prettyName = [prettyName stringByAppendingString:[components componentsJoinedByString:@" "]];
  216. } else {
  217. prettyName = [prettyName stringByAppendingString:selectorName];
  218. }
  219. return prettyName;
  220. }
  221. + (NSArray *)prettyArgumentComponentsForMethod:(Method)method
  222. {
  223. NSMutableArray *components = [NSMutableArray array];
  224. NSString *selectorName = NSStringFromSelector(method_getName(method));
  225. NSArray *selectorComponents = [selectorName componentsSeparatedByString:@":"];
  226. unsigned int numberOfArguments = method_getNumberOfArguments(method);
  227. for (unsigned int argIndex = kFLEXNumberOfImplicitArgs; argIndex < numberOfArguments; argIndex++) {
  228. char *argType = method_copyArgumentType(method, argIndex);
  229. NSString *readableArgType = [self readableTypeForEncoding:@(argType)];
  230. free(argType);
  231. NSString *prettyComponent = [NSString stringWithFormat:@"%@:(%@) ", [selectorComponents objectAtIndex:argIndex - kFLEXNumberOfImplicitArgs], readableArgType];
  232. [components addObject:prettyComponent];
  233. }
  234. return components;
  235. }
  236. #pragma mark - Method Calling/Field Editing (Public)
  237. + (id)performSelector:(SEL)selector onObject:(id)object withArguments:(NSArray *)arguments error:(NSError * __autoreleasing *)error
  238. {
  239. // Bail if the object won't respond to this selector.
  240. if (![object respondsToSelector:selector]) {
  241. if (error) {
  242. NSDictionary *userInfo = @{ NSLocalizedDescriptionKey : [NSString stringWithFormat:@"%@ does not respond to the selector %@", object, NSStringFromSelector(selector)]};
  243. *error = [NSError errorWithDomain:FLEXRuntimeUtilityErrorDomain code:FLEXRuntimeUtilityErrorCodeDoesNotRecognizeSelector userInfo:userInfo];
  244. }
  245. return nil;
  246. }
  247. // Build the invocation
  248. NSMethodSignature *methodSignature = [object methodSignatureForSelector:selector];
  249. NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:methodSignature];
  250. [invocation setSelector:selector];
  251. [invocation setTarget:object];
  252. [invocation retainArguments];
  253. // Always self and _cmd
  254. NSUInteger numberOfArguments = [methodSignature numberOfArguments];
  255. for (NSUInteger argumentIndex = kFLEXNumberOfImplicitArgs; argumentIndex < numberOfArguments; argumentIndex++) {
  256. NSUInteger argumentsArrayIndex = argumentIndex - kFLEXNumberOfImplicitArgs;
  257. id argumentObject = [arguments count] > argumentsArrayIndex ? [arguments objectAtIndex:argumentsArrayIndex] : nil;
  258. // NSNull in the arguments array can be passed as a placeholder to indicate nil. We only need to set the argument if it will be non-nil.
  259. if (argumentObject && ![argumentObject isKindOfClass:[NSNull class]]) {
  260. const char *typeEncodingCString = [methodSignature getArgumentTypeAtIndex:argumentIndex];
  261. if (typeEncodingCString[0] == @encode(id)[0] || typeEncodingCString[0] == @encode(Class)[0]) {
  262. // Object
  263. [invocation setArgument:&argumentObject atIndex:argumentIndex];
  264. } else if ([argumentObject isKindOfClass:[NSValue class]]){
  265. // Primitive boxed in NSValue
  266. NSValue *argumentValue = (NSValue *)argumentObject;
  267. // Ensure that the type encoding on the NSValue matches the type encoding of the argument in the method signature
  268. if (strcmp([argumentValue objCType], typeEncodingCString) != 0) {
  269. if (error) {
  270. NSDictionary *userInfo = @{ NSLocalizedDescriptionKey : [NSString stringWithFormat:@"Type encoding mismatch for agrument at index %lu. Value type: %s; Method argument type: %s.", (unsigned long)argumentsArrayIndex, [argumentValue objCType], typeEncodingCString]};
  271. *error = [NSError errorWithDomain:FLEXRuntimeUtilityErrorDomain code:FLEXRuntimeUtilityErrorCodeArgumentTypeMismatch userInfo:userInfo];
  272. }
  273. return nil;
  274. }
  275. NSUInteger bufferSize = 0;
  276. @try {
  277. // NSGetSizeAndAlignment barfs on type encoding for bitfields.
  278. NSGetSizeAndAlignment(typeEncodingCString, &bufferSize, NULL);
  279. } @catch (NSException *exception) { }
  280. if (bufferSize > 0) {
  281. void *buffer = calloc(bufferSize, 1);
  282. [argumentValue getValue:buffer];
  283. [invocation setArgument:buffer atIndex:argumentIndex];
  284. free(buffer);
  285. }
  286. }
  287. }
  288. }
  289. // Try to invoke the invocation but guard against an exception being thrown.
  290. BOOL successfullyInvoked = NO;
  291. @try {
  292. // Some methods are not fit to be called...
  293. // Looking at you -[UIResponder(UITextInputAdditions) _caretRect]
  294. [invocation invoke];
  295. successfullyInvoked = YES;
  296. } @catch (NSException *exception) {
  297. // Bummer...
  298. if (error) {
  299. NSDictionary *userInfo = @{ NSLocalizedDescriptionKey : [NSString stringWithFormat:@"Exception thrown while performing selector %@ on object %@", object, NSStringFromSelector(selector)]};
  300. *error = [NSError errorWithDomain:FLEXRuntimeUtilityErrorDomain code:FLEXRuntimeUtilityErrorCodeInvocationFailed userInfo:userInfo];
  301. }
  302. }
  303. // Retreive the return value and box if necessary.
  304. id returnObject = nil;
  305. if (successfullyInvoked) {
  306. const char *returnType = [methodSignature methodReturnType];
  307. if (returnType[0] == @encode(id)[0] || returnType[0] == @encode(Class)[0]) {
  308. __unsafe_unretained id objectReturnedFromMethod = nil;
  309. [invocation getReturnValue:&objectReturnedFromMethod];
  310. returnObject = objectReturnedFromMethod;
  311. } else if (returnType[0] != @encode(void)[0]) {
  312. void *returnValue = malloc([methodSignature methodReturnLength]);
  313. if (returnValue) {
  314. [invocation getReturnValue:returnValue];
  315. returnObject = [self valueForPrimitivePointer:returnValue objCType:returnType];
  316. free(returnValue);
  317. }
  318. }
  319. }
  320. return returnObject;
  321. }
  322. + (NSString *)editableJSONStringForObject:(id)object
  323. {
  324. NSString *editableDescription = nil;
  325. if (object) {
  326. // This is a hack to use JSON serialzation for our editable objects.
  327. // NSJSONSerialization doesn't allow writing fragments - the top level object must be an array or dictionary.
  328. // We always wrap the object inside an array and then strip the outter square braces off the final string.
  329. NSArray *wrappedObject = @[object];
  330. if ([NSJSONSerialization isValidJSONObject:wrappedObject]) {
  331. NSString *wrappedDescription = [[NSString alloc] initWithData:[NSJSONSerialization dataWithJSONObject:wrappedObject options:0 error:NULL] encoding:NSUTF8StringEncoding];
  332. editableDescription = [wrappedDescription substringWithRange:NSMakeRange(1, [wrappedDescription length] - 2)];
  333. }
  334. }
  335. return editableDescription;
  336. }
  337. + (id)objectValueFromEditableJSONString:(NSString *)string
  338. {
  339. id value = nil;
  340. // nil for empty string/whitespace
  341. if ([[string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] length] > 0) {
  342. value = [NSJSONSerialization JSONObjectWithData:[string dataUsingEncoding:NSUTF8StringEncoding] options:NSJSONReadingAllowFragments error:NULL];
  343. }
  344. return value;
  345. }
  346. + (NSValue *)valueForNumberWithObjCType:(const char *)typeEncoding fromInputString:(NSString *)inputString
  347. {
  348. NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
  349. [formatter setNumberStyle:NSNumberFormatterDecimalStyle];
  350. NSNumber *number = [formatter numberFromString:inputString];
  351. // Make sure we box the number with the correct type encoding so it can be propperly unboxed later via getValue:
  352. NSValue *value = nil;
  353. if (strcmp(typeEncoding, @encode(char)) == 0) {
  354. char primitiveValue = [number charValue];
  355. value = [NSValue value:&primitiveValue withObjCType:typeEncoding];
  356. } else if (strcmp(typeEncoding, @encode(int)) == 0) {
  357. int primitiveValue = [number intValue];
  358. value = [NSValue value:&primitiveValue withObjCType:typeEncoding];
  359. } else if (strcmp(typeEncoding, @encode(short)) == 0) {
  360. short primitiveValue = [number shortValue];
  361. value = [NSValue value:&primitiveValue withObjCType:typeEncoding];
  362. } else if (strcmp(typeEncoding, @encode(long)) == 0) {
  363. long primitiveValue = [number longValue];
  364. value = [NSValue value:&primitiveValue withObjCType:typeEncoding];
  365. } else if (strcmp(typeEncoding, @encode(long long)) == 0) {
  366. long long primitiveValue = [number longLongValue];
  367. value = [NSValue value:&primitiveValue withObjCType:typeEncoding];
  368. } else if (strcmp(typeEncoding, @encode(unsigned char)) == 0) {
  369. unsigned char primitiveValue = [number unsignedCharValue];
  370. value = [NSValue value:&primitiveValue withObjCType:typeEncoding];
  371. } else if (strcmp(typeEncoding, @encode(unsigned int)) == 0) {
  372. unsigned int primitiveValue = [number unsignedIntValue];
  373. value = [NSValue value:&primitiveValue withObjCType:typeEncoding];
  374. } else if (strcmp(typeEncoding, @encode(unsigned short)) == 0) {
  375. unsigned short primitiveValue = [number unsignedShortValue];
  376. value = [NSValue value:&primitiveValue withObjCType:typeEncoding];
  377. } else if (strcmp(typeEncoding, @encode(unsigned long)) == 0) {
  378. unsigned long primitiveValue = [number unsignedLongValue];
  379. value = [NSValue value:&primitiveValue withObjCType:typeEncoding];
  380. } else if (strcmp(typeEncoding, @encode(unsigned long long)) == 0) {
  381. unsigned long long primitiveValue = [number unsignedLongValue];
  382. value = [NSValue value:&primitiveValue withObjCType:typeEncoding];
  383. } else if (strcmp(typeEncoding, @encode(float)) == 0) {
  384. float primitiveValue = [number floatValue];
  385. value = [NSValue value:&primitiveValue withObjCType:typeEncoding];
  386. } else if (strcmp(typeEncoding, @encode(double)) == 0) {
  387. double primitiveValue = [number doubleValue];
  388. value = [NSValue value:&primitiveValue withObjCType:typeEncoding];
  389. }
  390. return value;
  391. }
  392. + (void)enumerateTypesInStructEncoding:(const char *)structEncoding usingBlock:(void (^)(NSString *structName, const char *fieldTypeEncoding, NSString *prettyTypeEncoding, NSUInteger fieldIndex, NSUInteger fieldOffset))typeBlock
  393. {
  394. if (structEncoding && structEncoding[0] == '{') {
  395. const char *equals = strchr(structEncoding, '=');
  396. if (equals) {
  397. const char *nameStart = structEncoding + 1;
  398. NSString *structName = [@(structEncoding) substringWithRange:NSMakeRange(nameStart - structEncoding, equals - nameStart)];
  399. NSUInteger fieldAlignment = 0;
  400. NSUInteger structSize = 0;
  401. @try {
  402. // NSGetSizeAndAlignment barfs on type encoding for bitfields.
  403. NSGetSizeAndAlignment(structEncoding, &structSize, &fieldAlignment);
  404. } @catch (NSException *exception) { }
  405. if (structSize > 0) {
  406. NSUInteger runningFieldIndex = 0;
  407. NSUInteger runningFieldOffset = 0;
  408. const char *typeStart = equals + 1;
  409. while (*typeStart != '}') {
  410. NSUInteger fieldSize = 0;
  411. // If the struct type encoding was successfully handled by NSGetSizeAndAlignment above, we *should* be ok with the field here.
  412. const char *nextTypeStart = NSGetSizeAndAlignment(typeStart, &fieldSize, NULL);
  413. NSString *typeEncoding = [@(structEncoding) substringWithRange:NSMakeRange(typeStart - structEncoding, nextTypeStart - typeStart)];
  414. typeBlock(structName, [typeEncoding UTF8String], [self readableTypeForEncoding:typeEncoding], runningFieldIndex, runningFieldOffset);
  415. runningFieldOffset += fieldSize;
  416. // Padding to keep propper alignment. __attribute((packed)) structs will break here.
  417. // The type encoding is no different for packed structs, so it's not clear there's anything we can do for those.
  418. if (runningFieldOffset % fieldAlignment != 0) {
  419. runningFieldOffset += fieldAlignment - runningFieldOffset % fieldAlignment;
  420. }
  421. runningFieldIndex++;
  422. typeStart = nextTypeStart;
  423. }
  424. }
  425. }
  426. }
  427. }
  428. #pragma mark - Internal Helpers
  429. + (NSDictionary *)attributesDictionaryForProperty:(objc_property_t)property
  430. {
  431. NSString *attributes = @(property_getAttributes(property));
  432. // Thanks to MAObjcRuntime for inspiration here.
  433. NSArray *attributePairs = [attributes componentsSeparatedByString:@","];
  434. NSMutableDictionary *attributesDictionary = [NSMutableDictionary dictionaryWithCapacity:[attributePairs count]];
  435. for (NSString *attributePair in attributePairs) {
  436. [attributesDictionary setObject:[attributePair substringFromIndex:1] forKey:[attributePair substringToIndex:1]];
  437. }
  438. return attributesDictionary;
  439. }
  440. + (NSString *)appendName:(NSString *)name toType:(NSString *)type
  441. {
  442. NSString *combined = nil;
  443. if ([type characterAtIndex:[type length] - 1] == '*') {
  444. combined = [type stringByAppendingString:name];
  445. } else {
  446. combined = [type stringByAppendingFormat:@" %@", name];
  447. }
  448. return combined;
  449. }
  450. + (NSString *)readableTypeForEncoding:(NSString *)encodingString
  451. {
  452. // See https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/ObjCRuntimeGuide/Articles/ocrtTypeEncodings.html
  453. // class-dump has a much nicer and much more complete implementation for this task, but it is distributed under GPLv2 :/
  454. // See https://github.com/nygard/class-dump/blob/master/Source/CDType.m
  455. // Warning: this method uses multiple middle returns and macros to cut down on boilerplate.
  456. // The use of macros here was inspired by https://www.mikeash.com/pyblog/friday-qa-2013-02-08-lets-build-key-value-coding.html
  457. const char *encodingCString = [encodingString UTF8String];
  458. // Objects
  459. if (encodingCString[0] == '@') {
  460. NSString *class = [encodingString substringFromIndex:1];
  461. class = [class stringByReplacingOccurrencesOfString:@"\"" withString:@""];
  462. if ([class length] == 0) {
  463. class = @"id";
  464. } else {
  465. class = [class stringByAppendingString:@" *"];
  466. }
  467. return class;
  468. }
  469. // C Types
  470. #define TRANSLATE(ctype) \
  471. if (strcmp(encodingCString, @encode(ctype)) == 0) { \
  472. return (NSString *)CFSTR(#ctype); \
  473. }
  474. // Order matters here since some of the cocoa types are typedefed to c types.
  475. // We can't recover the exact mapping, but we choose to prefer the cocoa types.
  476. // This is not an exhaustive list, but it covers the most common types
  477. TRANSLATE(CGRect);
  478. TRANSLATE(CGPoint);
  479. TRANSLATE(CGSize);
  480. TRANSLATE(UIEdgeInsets);
  481. TRANSLATE(UIOffset);
  482. TRANSLATE(NSRange);
  483. TRANSLATE(CGAffineTransform);
  484. TRANSLATE(NSInteger);
  485. TRANSLATE(NSUInteger);
  486. TRANSLATE(CGFloat);
  487. TRANSLATE(BOOL);
  488. TRANSLATE(int);
  489. TRANSLATE(short);
  490. TRANSLATE(long);
  491. TRANSLATE(long long);
  492. TRANSLATE(unsigned char);
  493. TRANSLATE(unsigned int);
  494. TRANSLATE(unsigned short);
  495. TRANSLATE(unsigned long);
  496. TRANSLATE(unsigned long long);
  497. TRANSLATE(float);
  498. TRANSLATE(double);
  499. TRANSLATE(long double);
  500. TRANSLATE(char *);
  501. TRANSLATE(Class);
  502. TRANSLATE(objc_property_t);
  503. TRANSLATE(Ivar);
  504. TRANSLATE(Method);
  505. TRANSLATE(Category);
  506. TRANSLATE(NSZone *);
  507. TRANSLATE(SEL);
  508. TRANSLATE(void);
  509. #undef TRANSLATE
  510. // Qualifier Prefixes
  511. // Do this after the checks above since some of the direct translations (i.e. Method) contain a prefix.
  512. #define RECURSIVE_TRANSLATE(prefix, formatString) \
  513. if (encodingCString[0] == prefix) { \
  514. NSString *recursiveType = [self readableTypeForEncoding:[encodingString substringFromIndex:1]]; \
  515. return [NSString stringWithFormat:formatString, recursiveType]; \
  516. }
  517. // If there's a qualifier prefix on the encoding, translate it and then
  518. // recursively call this method with the rest of the encoding string.
  519. RECURSIVE_TRANSLATE('^', @"%@ *");
  520. RECURSIVE_TRANSLATE('r', @"const %@");
  521. RECURSIVE_TRANSLATE('n', @"in %@");
  522. RECURSIVE_TRANSLATE('N', @"inout %@");
  523. RECURSIVE_TRANSLATE('o', @"out %@");
  524. RECURSIVE_TRANSLATE('O', @"bycopy %@");
  525. RECURSIVE_TRANSLATE('R', @"byref %@");
  526. RECURSIVE_TRANSLATE('V', @"oneway %@");
  527. RECURSIVE_TRANSLATE('b', @"bitfield(%@)");
  528. #undef RECURSIVE_TRANSLATE
  529. // If we couldn't translate, just return the original encoding string
  530. return encodingString;
  531. }
  532. + (NSValue *)valueForPrimitivePointer:(void *)pointer objCType:(const char *)type
  533. {
  534. // CASE marcro inspired by https://www.mikeash.com/pyblog/friday-qa-2013-02-08-lets-build-key-value-coding.html
  535. #define CASE(ctype, selectorpart) \
  536. if(strcmp(type, @encode(ctype)) == 0) { \
  537. return [NSNumber numberWith ## selectorpart: *(ctype *)pointer]; \
  538. }
  539. CASE(BOOL, Bool);
  540. CASE(unsigned char, UnsignedChar);
  541. CASE(short, Short);
  542. CASE(unsigned short, UnsignedShort);
  543. CASE(int, Int);
  544. CASE(unsigned int, UnsignedInt);
  545. CASE(long, Long);
  546. CASE(unsigned long, UnsignedLong);
  547. CASE(long long, LongLong);
  548. CASE(unsigned long long, UnsignedLongLong);
  549. CASE(float, Float);
  550. CASE(double, Double);
  551. #undef CASE
  552. NSValue *value = nil;
  553. @try {
  554. value = [NSValue valueWithBytes:pointer objCType:type];
  555. } @catch (NSException *exception) {
  556. // Certain type encodings are not supported by valueWithBytes:objCType:. Just fail silently if an exception is thrown.
  557. }
  558. return value;
  559. }
  560. @end