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// DogToy.h
@interface DogToy : RLMObject
@property NSString *name;
@end
// Dog.h
@interface Dog : RLMObject
@property NSString *name;
@property int age;
@property NSString *color;
// To-one relationship
@property DogToy *favoriteToy;
@end
// Enable Dog for use in RLMArray
RLM_COLLECTION_TYPE(Dog)
// Person.h
// A person has a primary key ID, a collection of dogs, and can be a member of multiple clubs.
@interface Person : RLMObject
@property int _id;
@property NSString *name;
// To-many relationship - a person can have many dogs
@property RLMArray<Dog *><Dog> *dogs;
// Inverse relationship - a person can be a member of many clubs
@property (readonly) RLMLinkingObjects *clubs;
@end
RLM_COLLECTION_TYPE(Person)
// DogClub.h
@interface DogClub : RLMObject
@property NSString *name;
@property RLMArray<Person *><Person> *members;
@end
// Dog.m
@implementation Dog
@end
// DogToy.m
@implementation DogToy
@end
// Person.m
@implementation Person
// Define the primary key for the class
+ (NSString *)primaryKey {
    return @"_id";
}
// Define the inverse relationship to dog clubs
+ (NSDictionary *)linkingObjectsProperties {
    return @{
        @"clubs": [RLMPropertyDescriptor descriptorWithClass:DogClub.class propertyName:@"members"],
    };
}
@end
// DogClub.m
@implementation DogClub
@end

class Dog: Object {
    @Persisted var name = ""
    @Persisted var age = 0
    @Persisted var color = ""
    @Persisted var currentCity = ""
    @Persisted var citiesVisited: MutableSet<String>
    @Persisted var companion: AnyRealmValue
    // Map of city name -> favorite park in that city
    @Persisted var favoriteParksByCity: Map<String, String>
}
class Person: Object {
    @Persisted(primaryKey: true) var id = 0
    @Persisted var name = ""
    // To-many relationship - a person can have many dogs
    @Persisted var dogs: List<Dog>
    // Embed a single object.
    // Embedded object properties must be marked optional.
    @Persisted var address: Address?
}
class Address: EmbeddedObject {
    @Persisted var street: String?
    @Persisted var city: String?
    @Persisted var country: String?
    @Persisted var postalCode: String?
}

RLMRealm *realm = [RLMRealm defaultRealm];
// Open a thread-safe transaction.
[realm transactionWithBlock:^{
    // Get a dog to update.
    Dog *dog = [[Dog allObjectsInRealm: realm] firstObject];
    // Update some properties on the instance.
    // These changes are saved to the realm.
    dog.name = @"Wolfie";
    dog.age += 1;
}];

let realm = try! Realm()
// Get a dog to update
let dog = realm.objects(Dog.self).first!
// Open a thread-safe transaction
try! realm.write {
    // Update some properties on the instance.
    // These changes are saved to the realm
    dog.name = "Wolfie"
    dog.age += 1
}

RLMRealm *realm = [RLMRealm defaultRealm];
[realm transactionWithBlock:^() {
    // Create a person to take care of some dogs.
    Person *ali = [[Person alloc] initWithValue:@{@"_id": @1, @"name": @"Ali"}];
    [realm addObject:ali];
    // Find dogs younger than 2.
    RLMResults<Dog *> *puppies = [Dog objectsInRealm:realm where:@"age < 2"];
    // Batch update: give all puppies to Ali.
    [ali setValue:puppies forKey:@"dogs"];
}];

let realm = try! Realm()
try! realm.write {
    // Create a person to take care of some dogs.
    let person = Person(value: ["id": 1, "name": "Ali"])
    realm.add(person)
    let dog = Dog(value: ["name": "Rex", "age": 1])
    realm.add(dog)
    // Find dogs younger than 2.
    let puppies = realm.objects(Dog.self).filter("age < 2")
    // Give all puppies to Ali.
    person.setValue(puppies, forKey: "dogs")
}

RLMRealm *realm = [RLMRealm defaultRealm];
[realm transactionWithBlock:^{
    Person *jones = [[Person alloc] initWithValue:@{@"_id": @1234, @"name": @"Jones"}];
    // Add a new person to the realm. Since nobody with ID 1234
    // has been added yet, this adds the instance to the realm.
    [realm addOrUpdateObject:jones];
    
    Person *bowie = [[Person alloc] initWithValue:@{@"_id": @1234, @"name": @"Bowie"}];
    // Judging by the ID, it's the same person, just with a different name.
    // This overwrites the original entry (i.e. Jones -> Bowie).
    [realm addOrUpdateObject:bowie];
}];

let realm = try! Realm()
try! realm.write {
    let person1 = Person(value: ["id": 1234, "name": "Jones"])
    // Add a new person to the realm. Since nobody with ID 1234
    // has been added yet, this adds the instance to the realm.
    realm.add(person1, update: .modified)
    let person2 = Person(value: ["id": 1234, "name": "Bowie"])
    // Judging by the ID, it's the same person, just with a
    // different name. When `update` is:
    // - .modified: update the fields that have changed.
    // - .all: replace all of the fields regardless of
    //   whether they've changed.
    // - .error: throw an exception if a key with the same
    //   primary key already exists.
    realm.add(person2, update: .modified)
}

RLMRealm *realm = [RLMRealm defaultRealm];
[realm transactionWithBlock:^{
    // Only update the provided values.
    // Note that the "name" property will remain the same
    // for the person with primary key "_id" 123.
    [Person createOrUpdateModifiedInRealm:realm
        withValue:@{@"_id": @123, @"dogs": @[@[@"Buster", @5]]}];
}];

let realm = try! Realm()
try! realm.write {
    // Use .modified to only update the provided values.
    // Note that the "name" property will remain the same
    // for the person with primary key "id" 123.
    realm.create(Person.self,
                 value: ["id": 123, "dogs": [["Buster", 5]]],
                 update: .modified)
}

RLMRealm *realm = [RLMRealm defaultRealm];
[realm transactionWithBlock: ^{
    Contact *contact = [Contact objectInRealm:realm
                                forPrimaryKey:[[RLMObjectId alloc] initWithString:@"5f481c21f634a1f4eeaa7268" error:nil]];
    contact.address.street = @"Hollywood Upstairs Medical College";
    contact.address.city = @"Los Angeles";
    contact.address.postalCode = @"90210";
    NSLog(@"Updated contact: %@", contact);
}];

// Open the default realm
let realm = try! Realm()
let idOfPersonToUpdate = 123
// Find the person to update by ID
guard let person = realm.object(ofType: Person.self, forPrimaryKey: idOfPersonToUpdate) else {
    print("Person \(idOfPersonToUpdate) not found")
    return
}
try! realm.write {
    // Update the embedded object directly through the person
    // If the embedded object is null, updating these properties has no effect
    person.address?.street = "789 Any Street"
    person.address?.city = "Anytown"
    person.address?.postalCode = "12345"
    print("Updated person: \(person)")
}

RLMRealm *realm = [RLMRealm defaultRealm];
[realm transactionWithBlock: ^{
    Contact *contact = [Contact objectInRealm:realm
                                forPrimaryKey:[[RLMObjectId alloc] initWithString:@"5f481c21f634a1f4eeaa7268" error:nil]];
    Address *newAddress = [[Address alloc] init];
    newAddress.street = @"Hollywood Upstairs Medical College";
    newAddress.city = @"Los Angeles";
    newAddress.country = @"USA";
    newAddress.postalCode = @"90210";
    contact.address = newAddress;
    NSLog(@"Updated contact: %@", contact);
}];

// Open the default realm
let realm = try! Realm()
let idOfPersonToUpdate = 123
// Find the person to update by ID
guard let person = realm.object(ofType: Person.self, forPrimaryKey: idOfPersonToUpdate) else {
    print("Person \(idOfPersonToUpdate) not found")
    return
}
try! realm.write {
    let newAddress = Address()
    newAddress.street = "789 Any Street"
    newAddress.city = "Anytown"
    newAddress.country = "USA"
    newAddress.postalCode = "12345"
    // Overwrite the embedded object
    person.address = newAddress
    print("Updated person: \(person)")
}