CODEWITHSUNDEEP
iosrealm
mlevi
mlevi

Reputation: 1463

Updating an object in Realm

How exactly would I update an object in Realm? Can't seem to find anything on editing/updating objects. Any ideas? Thanks

Upvotes: 8

Views: 10702

Answers (4)

gagarwal
gagarwal

Reputation: 4244

You can use the following API from RLMRealm class:

– addOrUpdateObject:
– addOrUpdateObjectsFromArray:

https://realm.io/docs/objc/latest/api/Classes/RLMRealm.html#//api/name/addOrUpdateObject: https://realm.io/docs/objc/latest/api/Classes/RLMRealm.html#//api/name/addOrUpdateObjectsFromArray:

For updating the objects in Realm, you need to define some primary key in your RLMObject subclasses, so that Realm then knows what to update.

+ (NSString *) primaryKey
{
    return @"somePropertyNameAsString";
}

Upvotes: 4

A. Adam
A. Adam

Reputation: 3134

Here is a method I wrote to update my database which has a table called CDlevels.

You can call this method from any thread as it will allocate realm from that thread and do the needful.

-(void)updateLevel:(int)levelNo WithScore:(NSString*)strScore complete:(void (^)(BOOL))completed{

RLMRealm *realm = [RLMRealm defaultRealm];

NSPredicate *pred = [NSPredicate predicateWithFormat:@"levelNo = %d",levelNo];

RLMResults *RLMLevels = [CDLevels objectsWithPredicate:pred];

CDLevels *myLevel = [[CDLevels alloc]init];

myLevel = [RLMLevels objectAtIndex:0];

[realm beginWriteTransaction];
myLevel.score = strScore;
[realm commitWriteTransaction];

completed(YES);

}

This is how you can call this method, say to update level 1 with a score 100

[self updateLevel:1 WithScore:@"100" complete:^(BOOL completed) {

        if (completed) {
             NSLog(@"score updated");
        }

    }];

I have tasted this and it works very cool. I am trying to change one of my coredata app to Realm.

Hope this help. If the answer flagged as an answer is wrong please correct it.

This is a primitive method and I believe it can be made better.

cheers

Upvotes: -1

Jaymon
Jaymon

Reputation: 5748

Here is the documentation on updating objects in Realm.

And here is another option to update objects than the one discussed in the other answers.

A lot of times, when I want to update objects, I only really need to update one or two properties, one annoying thing about Realm is property changes of a persisted object need to be wrapped in a write transaction, so I usually add a wrapper method to my objects to clean the interface up a bit:

@implementation SomeRealmClass

    - (void)update:(void (^)(SomeRealmClass *instance))updateBlock
    {
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
            RLMRealm *realm = [RLMRealm defaultRealm];
            [realm beginWriteTransaction];
            updateBlock(self);
            [realm commitWriteTransaction];

        });
    }

@end

This way, I can update an object like so:

SomeRealmClass *instance = [[SomeRealmClass allObjects] objectAtIndex:0];

[instance update:^(SomeRealmClass *instance) {
    instance.foo = @"foo 2";
    instance.bar = @"bar 2";
}];

Upvotes: 4

segiddins
segiddins

Reputation: 4120

In Realm, whenever you retrieve an object from the database, you can update its properties and those changes will be reflected in the database.

Upvotes: 2

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