awakeFromInsert用嵌套上下文调用两次

问题描述

这个项目使用Mogenerator和Magical Record。我跟踪了一个错误，事实是 awakeFromInsert 被调用两次。一次为我的每一个上下文我推定。这是一个问题，因为我需要听这NSManagedObject的NSNotifications像这样：

This project uses Mogenerator and Magical Record. I have tracked down a bug to the fact that awakeFromInsert is getting called twice. Once for each of my contexts I presume. This is an issue because I need to listen for NSNotifications on this NSManagedObject like this:

- (void)awakeFromInsert
{
    // Listen for a return from background mode
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(enteringForeground:) name:UIApplicationWillEnterForegroundNotification object:nil];
}

但是awakeFromInsert get被调用两次是很烦人。

But awakeFromInsert get's called twice which is rather annoying. I want to call a method ONCE when my NSManagedObject is first created.

在搜索。然而，我不能看到我可以添加一个类别到NSManagedObject当使用Mogenerator和MagicalRecord。没有一些复杂的重写。

After searching this solution seems to make a lot of sense. However I can't see how I can add a category onto NSManagedObject when using Mogenerator and MagicalRecord. Without some complex overriding.

在MagicalRecord MR_createEntity 调用

In MagicalRecord MR_createEntity calls

if ([self respondsToSelector:@selector(insertInManagedObjectContext:)]) 
    {
        id entity = [self performSelector:@selector(insertInManagedObjectContext:) withObject:context];
        return entity;
    }

这个问题有没有更好的解决方案？

Is there a neater solution to this issue?

推荐答案

好吧，这感觉非常黑客，但似乎工作。我在我的人类可读的NSManagedObject类上创建了以下类方法：

Ok well this feels very hacky but appears to work. I created the following class methods on my human readable NSManagedObject class:

+ (id)insertInManagedObjectContext:(NSManagedObjectContext*)moc_ {

    JWBoard *newobject = [super insertInManagedObjectContext:moc_];
    [JWBoard awakeFromCreate:newobject];
    return newobject;
}

+ (void)awakeFromCreate:(JWBoard *)board
{
    // do setup stuff & add observers
}

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