YYModel Documentation

To perform custom logic or validation during conversion, implement these two instance methods:

• - (BOOL)modelCustomTransformFromDictionary:(NSDictionary *)dic: Called after JSON is converted to a model. Return YES if valid, or NO to ignore the model. Use this for manual type conversion (e.g., timestamp to NSDate).
• - (BOOL)modelCustomTransformToDictionary:(NSMutableDictionary *)dic: Called before the model is converted to JSON. Return YES if valid, or NO to ignore the conversion.

@implementation User
- (BOOL)modelCustomTransformFromDictionary:(NSDictionary *)dic {
    // Custom logic here
    return YES;
}

- (BOOL)modelCustomTransformToDictionary:(NSMutableDictionary *)dic {
    // Custom logic here
    return YES;
}
@end

YYModel provides helper methods to simplify the implementation of standard Objective-C protocols. Instead of manually mapping every property, call the yy_model prefixed methods within the standard protocol methods.

@implementation YYShadow
- (void)encodeWithCoder:(NSCoder *)aCoder { [self yy_modelEncodeWithCoder:aCoder]; }
- (id)initWithCoder:(NSCoder *)aDecoder { self = [super init]; return [self yy_modelInitWithCoder:aDecoder]; }
- (id)copyWithZone:(NSZone *)zone { return [self yy_modelCopy]; }
- (NSUInteger)hash { return [self yy_modelHash]; }
- (BOOL)isEqual:(id)object { return [self yy_modelIsEqual:object]; }
- (NSString *)description { return [self yy_modelDescription]; }
@end

For container properties like NSArray, NSSet, or NSMutableDictionary, you must specify the type of the elements contained within them by implementing the + (NSDictionary *)modelContainerPropertyGenericClass class method. The value in the returned dictionary should be the Class or the class name as a string.

```objc
@implementation Attributes
+ (NSDictionary *)modelContainerPropertyGenericClass {
    return @{@

You can control which properties are included or excluded during conversion by implementing the following class methods:

• + (NSArray *)modelPropertyBlacklist: Properties in this list will be ignored.
• + (NSArray *)modelPropertyWhitelist: Only properties in this list will be processed.

```objc
@implementation Attributes
+ (NSArray *)modelPropertyBlacklist {
    return @[@"test1", @

If your model property names do not match the JSON keys, implement the + (NSDictionary *)modelCustomPropertyMapper class method. You can map a property to a single key path string or an array of key paths.

• JSON to Model: If a property maps to multiple keys, YYModel uses the first non-null value found in the order provided.
• Model to JSON: If a property maps to multiple keys, YYModel only processes the first key path. If multiple properties map to the same key, it uses any non-null value.

```objc
@implementation Book
+ (NSDictionary *)modelCustomPropertyMapper {
    return @{@

Use yy_modelWithJSON: to convert JSON (NSData, NSString, or NSDictionary) into a model instance. Use yy_modelToJSONObject to convert a model instance back into a JSON object (NSDictionary).

// Convert json to model:
User *user = [User yy_modelWithJSON:json];

// Convert model to json:
NSDictionary *json = [user yy_modelToJSONObject];