实体序列化

gistfile1.m

+ (NSData *)jsonDataFromObject:(id)object;
{
	static Class NSObjectClass;
	static NSCharacterSet *ClassRestrictiveCharacterSet;
	
	if( !NSObjectClass )
	{
		NSObjectClass = [NSObject class];
		ClassRestrictiveCharacterSet = [NSCharacterSet characterSetWithCharactersInString:@" @\""];
	}
	
	NSMutableDictionary *kvpDict = [[NSMutableDictionary alloc] init];

	Class classItr = [object class];
	while( classItr && ( classItr != NSObjectClass ) )
	{
		unsigned int propertyCount = 0;
		objc_property_t *properties = class_copyPropertyList( classItr, &propertyCount );
		for( unsigned int ii = 0; ii < propertyCount; ++ii )
		{
			objc_property_t property = properties[ ii ];

			NSString *propertyName = @( property_getName( property ) );
			const char *backingIvarName = property_copyAttributeValue( property, "V" );
			Ivar ivar = class_getInstanceVariable( classItr, backingIvarName );
			id value = nil;
			
			NSString *propertyTypeName = @( property_copyAttributeValue( property, "T" ) );
			switch( [propertyTypeName characterAtIndex:0] )
			{
				case _C_ID:
					propertyTypeName = [propertyTypeName stringByTrimmingCharactersInSet:ClassRestrictiveCharacterSet];
					if( [propertyTypeName isEqualToString:@"NSString"]
						|| [propertyTypeName isEqualToString:@"NSNumber"]
						|| [propertyTypeName isEqualToString:@"NSArray"]
						|| [propertyTypeName isEqualToString:@"NSDictionary"]
						|| [propertyTypeName isEqualToString:@"NSNull"])
					{
						value = [object valueForKey:propertyName];
					}
					else if( [propertyTypeName isEqualToString:@"NSData"] )
					{
						NSData *dataValue = [object valueForKey:propertyName];
						value = [[NSString alloc] initWithData:dataValue encoding:NSUTF8StringEncoding];
					}
					else if( [propertyTypeName isEqualToString:@"NSURL"] )
					{
						NSURL *urlValue = [object valueForKey:propertyName];
						value = [urlValue absoluteString];
					}
					break;
				case _C_CHR:
				{
					char charValue = *( (char*)( (__bridge void*)object + ivar_getOffset( ivar ) ) );
					value = [NSNumber numberWithChar:charValue];
				}
					break;
				case _C_UCHR:
				{
					unsigned char unsignedCharValue = *( (unsigned char*)( (__bridge void*)object + ivar_getOffset( ivar ) ) );
					value = [NSNumber numberWithUnsignedChar:unsignedCharValue];
				}
					break;
				case _C_SHT:
				{
					short shortValue = *( (short*)( (__bridge void*)object + ivar_getOffset( ivar ) ) );
					value = [NSNumber numberWithShort:shortValue];
				}
					break;
				case _C_USHT:
				{
					unsigned char unsignedShortValue = *( (unsigned short*)( (__bridge void*)object + ivar_getOffset( ivar ) ) );
					value = [NSNumber numberWithUnsignedShort:unsignedShortValue];
				}
					break;
				case _C_INT:
				{
					int intValue = *( (int*)( (__bridge void*)object + ivar_getOffset( ivar ) ) );
					value = [NSNumber numberWithInteger:intValue];
				}
					break;
				case _C_UINT:
				{
					unsigned int unsignedIntValue = *( (unsigned int*)( (__bridge void*)object + ivar_getOffset( ivar ) ) );
					value = [NSNumber numberWithUnsignedInteger:unsignedIntValue];
				}
					break;
				case _C_LNG:
				{
					long longValue = *( (long*)( (__bridge void*)object + ivar_getOffset( ivar ) ) );
					value = [NSNumber numberWithLong:longValue];
				}
					break;
				case _C_ULNG:
				{
					unsigned long unsignedLongValue = *( (unsigned long*)( (__bridge void*)object + ivar_getOffset( ivar ) ) );
					value = [NSNumber numberWithUnsignedLong:unsignedLongValue];
				}
					break;
				case _C_LNG_LNG:
				{
					long long longLongValue = *( (long long*)( (__bridge void*)object + ivar_getOffset( ivar ) ) );
					value = [NSNumber numberWithLongLong:longLongValue];
				}
					break;
				case _C_ULNG_LNG:
				{
					unsigned long long unsignedLongLongValue = *( (unsigned long long*)( (__bridge void*)object + ivar_getOffset( ivar ) ) );
					value = [NSNumber numberWithUnsignedLongLong:unsignedLongLongValue];
				}
					break;
				case _C_FLT:
				{
					float floatValue = *( (float*)( (__bridge void*)object + ivar_getOffset( ivar ) ) );
					value = [NSNumber numberWithFloat:floatValue];
				}
					break;
				case _C_DBL:
				{
					double doubleValue = *( (double*)( (__bridge void*)object + ivar_getOffset( ivar ) ) );
					value = [NSNumber numberWithDouble:doubleValue];
				}
					break;
				case _C_BOOL:
				{
					bool boolValue = *( (bool*)( (__bridge void*)object + ivar_getOffset( ivar ) ) );
					value = [NSNumber numberWithBool:boolValue];
				}
					break;
			}
			
			if( value )
			{
				[kvpDict setObject:value forKey:propertyName];
			}
		}
		
		classItr = class_getSuperclass( classItr );
	}
	
	NSError *error = nil;
	return [NSJSONSerialization dataWithJSONObject:kvpDict options:0 error:&error];
}