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Cosy NSObject
// (C)opyright 2018-04-25 Dirk Holtwick, holtwick.it. All rights reserved.
#import <Foundation/Foundation.h>
/* A dictionary like object that allows to define custom dynamic properties
* for typed and easy access. Only simple types like string, number, array and
* dictionary are supported. It is mainly thought to be a convenience class that
* can be serialized easily to JSON and other formats.
*
* MAKE SURE to add @dynamic for any property you define in a subclass of SeaObject!
*/
@interface SeaObject : NSObject <NSCopying>
@property (nonatomic, assign) BOOL needsSave;
@property (nonatomic, readonly) NSUInteger count;
@property (nonatomic, readonly) NSEnumerator *keyEnumerator;
@property (nonatomic, readonly) NSArray<NSString *> *allKeys;
@property (nonatomic, copy) NSDictionary *jsonDictionary;
- (instancetype)initWithDictionary:(NSDictionary *)dict;
- (void)configure;
- (id)objectForKey:(id)aKey;
- (void)setObject:(id)anObject forKey:(id<NSCopying>)aKey;
- (void)removeObjectForKey:(id)key;
- (void)setObject:(id)obj forKeyedSubscript:(NSString *)key;
- (id)objectForKeyedSubscript:(NSString *)key;
- (BOOL)writeAsJSON:(id)path;
- (BOOL)readAsJSON:(id)path;
@end
// (C)opyright 2018-04-25 Dirk Holtwick, holtwick.it. All rights reserved.
#import "SeaObject.h"
@implementation SeaObject {
__strong NSMutableDictionary *_properties;
BOOL _needsSave;
}
+ (void)initialize {
[super initialize];
if (self != [SeaObject self]) {
NSArray *danger = [self getDangerousPropertyNames];
if (danger) {
NSLog(@"In class <%@> dangerous properties have been identified. Add the follwing code:\n\n@dynamic %@\n",
NSStringFromClass(self),
[danger componentsJoinedByString:@", "]);
id reason = [NSString stringWithFormat:@"In class <%@> dangerous properties have been identified. Add the follwing code: @dynamic %@",
NSStringFromClass(self),
[danger componentsJoinedByString:@", "]];
@throw [NSException exceptionWithName:@"Missing @dynamic"
reason:reason
userInfo:nil];
}
}
}
- (void)setJsonDictionary:(NSDictionary *)obj {
[self willChangeValueForKey:@"allKeys"];
if (obj) {
_properties = [self cleanedObject:obj forImport:YES];
}
if (!_properties) {
_properties = [NSMutableDictionary dictionary];
}
[self didChangeValueForKey:@"allKeys"];
}
- (NSMutableDictionary *)jsonDictionary {
return [self cleanedObject:_properties forImport:NO] ?: [NSMutableDictionary dictionary];
}
- (void)configure {
// Can be overridden
}
- (instancetype)initWithDictionary:(NSDictionary *)dict {
self = [super init];
if (self) {
[self setJsonDictionary:dict];
[self configure];
}
return self;
}
- (instancetype)init {
self = [super init];
if (self) {
[self setJsonDictionary:nil];
[self configure];
}
return self;
}
#pragma mark - Subclassing
- (NSUInteger)count {
return _properties.count;
}
- (id)objectForKey:(id)aKey {
return [_properties objectForKey:aKey];
}
- (void)setObject:(id)value forKey:(id<NSCopying>)aKey {
NSString *key = (id)aKey;
if (!value) {
[self removeObjectForKey:key];
} else {
// Asset, Reference
if (!([value isKindOfClass:[NSNumber class]] ||
[value isKindOfClass:[NSArray class]] ||
[value isKindOfClass:[NSDictionary class]] ||
[value isKindOfClass:[SeaObject class]] ||
[value isKindOfClass:[NSString class]]
)) {
@throw [NSString stringWithFormat:@"Unsupported object class %@", NSStringFromClass([value class])];
}
id oldValue = [_properties objectForKey:key];
if (oldValue != value && ![oldValue isEqual:key]) {
[self willChangeValueForKey:key];
[_properties setObject:value forKey:key];
[self didChangeValueForKey:key];
self.needsSave = YES;
}
}
}
- (void)removeObjectForKey:(id)key {
id oldValue = [_properties objectForKey:key];
if (oldValue) {
[self willChangeValueForKey:key];
[_properties removeObjectForKey:key];
[self didChangeValueForKey:key];
}
}
- (NSEnumerator *)keyEnumerator {
return _properties.keyEnumerator;
}
- (NSArray<NSString *> *)allKeys {
return _properties.allKeys;
}
- (void)setObject:(id)obj forKeyedSubscript:(NSString *)key {
[self setObject:obj forKey:key];
}
- (id)objectForKeyedSubscript:(NSString *)key {
return [self objectForKey:key];
}
- (void)setValue:(id)value forUndefinedKey:(NSString *)key {
[self setObject:value forKey:key];
}
- (id)valueForUndefinedKey:(NSString *)key {
return [self objectForKey:key];
}
#pragma mark - Serializing
- (id)cleanedObject:(id)objectToBeCleaned forImport:(BOOL)forImport {
if (!objectToBeCleaned) {
return nil;
}
__strong id obj = objectToBeCleaned;
if ([obj isKindOfClass:[NSDictionary class]]) {
if (forImport) {
SeaObject *dict = [[SeaObject alloc] initWithDictionary:nil];
for(id key in obj) {
id value = [obj objectForKey:key];
if (value) { // Strip null
value = [self cleanedObject:value forImport:forImport];
if (value) { // Strip null
dict[key] = value;
}
}
}
obj = dict;
}
else {
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
for(id key in obj) {
id value = [obj objectForKey:key];
if (value) { // Strip null
value = [self cleanedObject:value forImport:forImport];
if (value) { // Strip null
dict[key] = value;
}
}
}
obj = dict;
}
}
else if ([obj isKindOfClass:[SeaObject class]]) {
if (!forImport) {
obj = [obj jsonDictionary];
}
}
else if ([obj isKindOfClass:[NSArray class]] || [obj isKindOfClass:[NSSet class]]) {
NSMutableArray *array = [NSMutableArray array];
for(id value in obj) {
if (value) { // Strip null
[array addObject:[self cleanedObject:value forImport:forImport]];
}
}
obj = array;
}
return obj;
}
#pragma mark - Check dynamic properties!
+ (NSArray *)getDangerousPropertyNames { // https://stackoverflow.com/a/11774276/140927
unsigned count;
objc_property_t *properties = class_copyPropertyList(self, &count);
NSMutableArray *dangerousPropertiyNames = [NSMutableArray array];
for (unsigned i = 0; i < count; i++) {
objc_property_t property = properties[i];
NSString *name = [NSString stringWithUTF8String:property_getName(property)];
NSString *attr = @(property_getAttributes(property));
if ([attr containsString:@",V_"]) {
[dangerousPropertiyNames addObject:name];
}
}
free(properties);
return dangerousPropertiyNames.count > 0 ? dangerousPropertiyNames : nil;
}
#pragma mark - Dynamic Properties
- (NSMethodSignature *)methodSignatureForSelector:(SEL)selector {
NSString *sel = NSStringFromSelector(selector);
// NSLog(@"methodSignatureForSelector:%@", sel);
if ([sel rangeOfString:@"set"].location == 0) {
return [NSMethodSignature signatureWithObjCTypes:"v@:@"];
} else {
return [NSMethodSignature signatureWithObjCTypes:"@@:"];
}
}
- (void)forwardInvocation:(NSInvocation *)invocation {
NSString *sel = NSStringFromSelector(invocation.selector);
// NSLog(@"forwardInvocation:%@", sel);
if ([sel rangeOfString:@"set"].location == 0) {
sel = [NSString stringWithFormat:@"%@%@",
[sel substringWithRange:NSMakeRange(3, 1)].lowercaseString,
[sel substringWithRange:NSMakeRange(4, sel.length-5)]];
id __unsafe_unretained obj;
[invocation getArgument:&obj atIndex:2];
[self setObject:obj forKey:sel];
} else {
id obj = [_properties objectForKey:sel];
[invocation setReturnValue:&obj];
}
}
#pragma mark - Debug
- (NSString *)description {
return [NSString stringWithFormat:@"<%@\n _properties=%@>",
self.className,
_properties];
}
- (id)copyWithZone:(NSZone *)zone {
return [[self.class alloc] initWithDictionary:[self jsonDictionary]];
}
#pragma mark - IO
- (BOOL)writeAsJSON:(id)path {
id data = [NSJSONSerialization dataWithJSONObject:self.jsonDictionary
options:NSJSONWritingPrettyPrinted
error:nil];
if (data) {
if ([data writeToFile:path atomically:YES]) {
self.needsSave = NO;
return YES;
}
}
return NO;
}
- (BOOL)readAsJSON:(id)path {
NSError *error = nil;
id data = [NSData dataWithContentsOfFile:path];
id json = [NSJSONSerialization JSONObjectWithData:data
options:NSJSONReadingMutableLeaves | NSJSONReadingMutableContainers
error:&error];
self.jsonDictionary = json;
self.needsSave = NO;
if (!json) {
NSLog(@"Error %@", error);
return NO;
}
return YES;
}
@end
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