Core Data Archives

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How to observe NSManagedObject changes in Core Data using Combine

Observing changes in Core Data NSManagedObject instances with Combine publishers can be a great solution to keep your user interface ...
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• 3 min read Apr 20, 2021 Combine Core Data

Data validation on insertion, update, and deletion in Core Data

Data validation in apps is important to make sure we save data conforming to the business rules. A name should ...
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• 3 min read Nov 10, 2020 Core Data

Derived Attributes to improve Core Data Fetch Performance

Derived attributes are available since iOS 13 and aim to improve fetch performance in many different scenarios. Although we have ...
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• 3 min read Nov 03, 2020 Core Data

Constraints in Core Data Entities explained

Constraints in Core Data are part of an entity configuration. Settings like the entity name and Spotlight display name might ...
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• 4 min read Oct 27, 2020 Core Data Swift

NSManagedObject events: handling state in Core Data

An NSManagedObject lifecycle goes from insertion and updates until deletion in the end. All those events come with their own ...
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• 4 min read Oct 20, 2020 Core Data Swift

How-to use Diffable Data Sources with Core Data

Diffable Data Sources were introduced at WWDC 2019 as a replacement for UICollectionViewDataSource and UITableViewDataSource. The API is available on ...
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• 6 min read Sep 22, 2020 Core Data Swift

Persistent History Tracking in Core Data

WWDC 2017 introduced a new concept available from iOS 11 which is persistent history tracking. It's Apple's answer for merging ...
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• 7 min read Sep 08, 2020 Core Data Swift

Write-Ahead Logging (WAL) disabled to force commits in Core Data

Write-Ahead Logging is the default journaling mode for Core Data SQLite stores since iOS 7 and OS X Mavericks. Journaling ...
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• 4 min read Aug 25, 2020 Core Data Swift

ValueTransformer in Core Data explained: Storing absolute URLs

ValueTransformers in Core Data are a powerful way of transforming values before they get inserted into the database and before ...
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• 7 min read Jul 14, 2020 Core Data Swift

Core Data Performance: 6 tips you should know

Writing Core Data code with performance in mind helps to prepare your app for the future. Your database might be ...
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• 5 min read Jun 02, 2020 Core Data Swift

NSFetchedResultsController extension to observe relationship changes

Apple provides us with great classes like the NSFetchedResultsController to interact with Core Data databases in our apps. The API ...
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• 8 min read Mar 24, 2020 Core Data Swift

Core Data and App extensions: Sharing a single database

Core Data got better and better over the years with improved APIs that make it easier to work with. The ...
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• 5 min read Oct 29, 2019 Core Data Swift

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