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# NSManagedObjectContextWillSaveNotification

A notification that posts before a context writes unsaved changes.

```
extern NSString * const NSManagedObjectContextWillSaveNotification;
```

## Discussion

This notification’s `object` is the context that’s about to save. Only use the notification to operate on the in-process save operation. For example, to insert additional managed objects. Don’t peform any asynchronous work or block the calling thread. [`NSManagedObjectContext`](/documentation/CoreData/NSManagedObjectContext) posts notifications to the same thread that creates it.

There is no `userInfo` dictionary.

---

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