What is the purpose of NSManagedObjectContext?
An object space to manipulate and track changes to managed objects.
How do I save an object in Core Data?
To save an object with Core Data, you can simply create a new instance of the NSManagedObject subclass and save the managed context. In the code above, we’ve created a new Person instance and saved it locally using Core Data.
What is an NSManagedObject?
In some respects, an NSManagedObject acts like a dictionary—it’s a generic container object that provides efficient storage for the properties defined by its associated NSEntityDescription instance. Therefore, typically you don’t need to define instance variables in subclasses.
Is NSManagedObjectContext thread safe?
The NSManagedObjectContext class isn’t thread safe. Plain and simple. You should never share managed object contexts between threads. This is a hard rule you shouldn’t break.
Is Core Data is thread safe?
Core Data is designed to work in a multithreaded environment. However, not every object under the Core Data framework is thread safe. To use Core Data in a multithreaded environment, ensure that: Managed object contexts are bound to the thread (queue) that they are associated with upon initialization.
How do I know if core data is saved?
Steps I followed are :
- Open finder and Press Command(Windows) + Shift + G .
- Go to the folder add ~/Library/Developer.
- Search for the DB name you’ve created as in my case it was my. db in SQLite.
- Download and install DB browser for SQLite.
- Click open database.
- Now drag and drop the DB file from your finder.
Where does core data store data?
Speed up your tests and SwiftUI previews by creating your Core Data stack with an in-memory store. The Core Data stack uses an on-disk SQLite store by default.
What is @NSManaged?
The formal definition (in the Core Data Apple Docs): Like the @dynamic attribute in Objective-C, the @NSManaged attribute informs the Swift compiler that the storage and implementation of a property will be provided at runtime.
What is Nsfetchrequestresult?
An abstract protocol used with parameterized fetch requests. Language.
When to use nsmanagedobjectcontext in core data?
In situations such as store migration, Core Data will create instances of NSManagedObjectContext for its own use. Under these circumstances, you cannot rely on any features of your custom subclass.
How to access the same nsmanagedobject across threads?
One way to get access to the same NSManagedObject across threads is to pass the NSManagedObjectID across threads and read the object: Note: newly created Core Data objects have temporary object ids until the object is saved for the first time. Temporary object ids cannot be used to read objects on other threads.
What happens when you create a managed object context?
When you create a managed object context, you have two options for its thread (queue) association: Private: The context creates and manages a private queue. Main: The context associates with the main queue and is dependent on the application’s event loop; otherwise, it’s similar to a private context.
What happens when you save changes in a child context?
When you save changes in a context, the changes are only committed “one store up.” If you save a child context, changes are pushed to its parent. Changes are not saved to the persistent store until the root context is saved. (A root managed object context is one whose parent context is nil .)