Cannot init the PersistentContainer

[YLKwan]

let persistentContainer = PersistentContainer()

Thread 1: Fatal error: 'try!' expression unexpectedly raised an error: AlecrimCoreData.PersistentContainerError.invalidManagedObjectModelURL

[vmartinelli]

Hello.

The framework is trying to infer the Core Data model URL using the framework name itself (AlecrimCoreData in this case). This code was made thinking about subclasses.

I think passing your Core Data model filename (without extension) as a constructor parameter may work. If not, let me know.

[YLKwan]

    public convenience init(name: String? = nil) {
        try! self.init(name: name, managedObjectModel: type(of: self).managedObjectModel(), storageType: .disk, persistentStoreURL: try! type(of: self).persistentStoreURL(), persistentStoreDescriptionOptions: nil, ubiquitousConfiguration: nil)
    }

The convenience 'init' method does not passing the 'name' parameter to 'managedObjectModel' method.

    public static func managedObjectModel(withName name: String? = nil, in bundle: Bundle? = nil) throws -> NSManagedObjectModel {
        let bundle = bundle ?? Bundle(for: Self.self)
        let name = name ?? bundle.bundleURL.deletingPathExtension().lastPathComponent

        let managedObjectModelURL = try self.managedObjectModelURL(withName: name, in: bundle)

        guard let managedObjectModel = NSManagedObjectModel(contentsOf: managedObjectModelURL) else {
            throw PersistentContainerError.managedObjectModelNotFound
        }

        return managedObjectModel
    }

And in the 'managedObjectModel' method, it using the bundle of AlecrimCoreData Framework but not the Application bundle.

Should I subclass the PersistentContainer before using it?

[kvacquier]

Same here, do you have any idea ?

[vmartinelli]

I'm going through personal problems, sorry for the delay in answering.

@YLKwan: Subclassing the PersistentContainer class may work, using a constructor like this:

public init() throws {
    let managedObjectModel = ...
    let persistentStoreURL = ...

    try super.init(managedObjectModel: managedObjectModel, storageType: .disk, persistentStoreURL: persistentStoreURL)
}

@kvacquier: A future update should improve how this is done in the framework.

[YLKwan]

try using this extension for temporary fix

import AlecrimCoreData
extension PersistentContainer {

	public convenience init(name: String? = nil) {
		try! self.init(name: name, managedObjectModel: type(of: self).managedObjectModel(withName: name, in: Bundle.main), storageType: .disk, persistentStoreURL: try! type(of: self).persistentStoreURL(), persistentStoreDescriptionOptions: nil, ubiquitousConfiguration: nil)
	}
}