CDShare - CoreData Share

Info

This work was inspired by how Apple iWork office suite applications work in iOS and a specific feature of how the documents are sharing between apps even in offline mode.

CDShare will answer the question:
How do we share CoreData between 2*n application, where n >= 1?

Before to go direct to the subject, let's have a short introduction for each part that is touched in this tutorial.

See the Wiki!

The contains documentation, samples, contributions, etc. Start there.

Setup

To run the example project, clone the repo, and run pod install from the Example directory first.

Requirements

iOS 11.0+ 
Xcode 10

Installation

CDShare is available through CocoaPods. To install it, simply add the following line to your Podfile:

pod 'CDShare'

Under the Example folder, you will find a project of how to use the CDShare.framework. The project will contain a showcase for an Application and an Extension for it and they will share the CoreData.

The logic of the framework looks like this:

1. Create a class/struct that implement ApplicationGroupInfo protocol.

struct ApplicationGroupInfoModel: ApplicationGroupInfo {
    var group: ApplicationIdentifier = ApplicationIdentifierModel(identifier: "group.voda.the.cdshare")
    var reading: ApplicationIdentifier = ApplicationIdentifierModel(identifier: "com.CDShareExample")
    var writing: [ApplicationIdentifier] = [ApplicationIdentifierModel(identifier: "com.CDShareExample.CDShareExampleToday")]
}

You can have diferent context for reading and writing, for the sake of the example I did use the same context.

Each parameter of the ApplicationGroupInfo protocol require to be descedent of the ApplicationIdentifier protocol.

struct ApplicationIdentifierModel: ApplicationIdentifier {
    var identifier: String
}

2. Create the CoreDataShareConfiguration instance.

let context: NSManagedObjectContext = ...
let configuration = try! CoreDataShareConfiguration(ApplicationGroupInfoModel(), readingContext: context, writingContext: context)

3. Create CoreDataShare instance.

let coreDataShare = try! CoreDataShare(configuration: configuration, viewContext: context)

4. Do not forget to add the class type that you want to update/reload objects in memory.

coreDataShare.sharedInScopeEntityNames = [String(describing: Counter.self)]

5. Add the notification of .CoreDataShareDidSave:.

let selector = #selector(reloadObjects)
NotificationCenter.default.addObserver(self, selector: selector, name: .CoreDataShareDidSave, object: nil)

Author

vodaion, vanea.voda@gmail.com

License

CDShare is available under the MIT license. See the LICENSE file for more info. Application documentation.