实例化NSManagedObject而不保存它 [英] Instantiate a NSManagedObject without saving it

问题描述

我得到了一个类：

@objc(User)
class User: NSManagedObject {

    @NSManaged var id: String

    //MARK: - Initialize
    convenience init(id: String,  context: NSManagedObjectContext?) {

        // Create the NSEntityDescription
        let entity = NSEntityDescription.entityForName("User", inManagedObjectContext: context!)


        // Super init the top init
        self.init(entity: entity!, insertIntoManagedObjectContext: context)


        // Init class variables
        self.id = id

    }
}

我在ViewController中创建一个新用户：

I create a new User in a ViewController :

managedObjectContext = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext!

var aUser = User(id: "500T", context: managedObjectContext)

我有另一个班级Group，其中Group有很多用户。为了节省用户，我做了类似的事情。

I have another class "Group" where Group have many Users. To save user I do something like

aGroup!.users = NSSet(array: users!)
!managedObjectContext.save

我不想保存所有用户。如何在不保存的情况下实例化用户？

I don't want to save all users. How can I instantiate a user without saving it ?

推荐答案

我找到了答案，并向用户init添加了一个needSave布尔值。也许这不是最好的答案，但是它有效。

I found my answer and add a needSave boolean to the user init. Maybe it's not the best answer but it's working.

@objc(User)
class User: NSManagedObject {

    @NSManaged var id: String

    //MARK: - Initialize
    convenience init(id: String, needSave: Bool,  context: NSManagedObjectContext?) {

        // Create the NSEntityDescription
        let entity = NSEntityDescription.entityForName("User", inManagedObjectContext: context!)


        if(!needSave) {
            self.init(entity: entity!, insertIntoManagedObjectContext: nil)
        } else {
            self.init(entity: entity!, insertIntoManagedObjectContext: context)
        }

        // Init class variables
        self.id = id

    }
}

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