Transformer is a framework written in Swift that makes it easy for you to convert your database models to plain objects.

• Features
• Usage
• Requirements
• Communication
• Installation
• Author
• License

Features:

• Mapping database models to plain objects
• Nested Objects (stand alone, in arrays or in dictionaries)
• Struct support

Supported frameworks

• CoreData
• Realm

Usage

To support mapping, a class or struct just needs to implement the Mappable protocol which includes the following functions:

init(with resolver: Resolver) throws

CoreData:

class CategoryPlainObject: Mappable {
    
    let id: Int64
    let name: String
    
    var positions: [PositionPlainObject] = [] // Array of objects
    
    required init(with resolver: Resolver) throws {
        
        self.id        = try resolver.value("id")
        self.name      = try resolver.value("name")
        self.positions = try resolver.value("positions")
    }
}

class PositionPlainObject: Mappable {
    
    let id: Int64
    let name: String
    let price: Double
    
    var category: CategoryPlainObject? = nil // Nested object
    
    required init(with resolver: Resolver) throws {
        
        self.id       = try  resolver.value("id")
        self.name     = try  resolver.value("name")
        self.price    = try  resolver.value("price")
        self.category = try? resolver.value("category")
    }
}

struct User: Mappable {
    
    let id: Int64
    let name: String
    
    init(with resolver: Resolver) throws {
        
        self.id   = try resolver.value("id")
        self.name = try resolver.value("name")
    }
}

Example - mapping from CoreData objects

/// A simple protocol for a nice exmaple

protocol Storable: class {
    
    static var entityName: String { get }
}

extension Storable where Self: NSManagedObject {
    
    static var entityName: String {
        
        return NSStringFromClass(self).components(separatedBy: ".").last ?? ""
    }
    
    init(in context: NSManagedObjectContext) {
        
        guard let entity = NSEntityDescription.entity(forEntityName: Self.entityName, in: context) else {
            
            fatalError("Cannot create entity for entity name: \(self.entityName)")
        }
        
        self.init(entity: entity, insertInto: context)
    }
}

class CategoryModelObject: NSManagedObject, Storable {
    
    @NSManaged var id: Int64
    @NSManaged var name: String
    @NSManaged var positions: NSSet
}

class PositionModelObject: NSManagedObject, Storable {
    
    @NSManaged var id: Int64
    @NSManaged var name: String
    @NSManaged var price: Double
    @NSManaged var category: CategoryModelObject
}

let categoryModelObject = CategoryModelObject(in: context)
let positionModelObject = PositionModelObject(in: context)

/// Fill some data to categoryModelObject & positionModelObject

...

/// And mapping from CoreData objects

let transformer = Transformer(from: .coredata)

let categoryPlainObject: CategoryPlainObject = try transformer.transform(from: categoryModelObject)
let positionPlainObject: PositionPlainObject = try transformer.transform(from: positionModelObject)

Requirements

• iOS 8.0+ / macOS 10.9+ / tvOS 9.0+ / watchOS 2.0+
• Xcode 8.1, 8.2, 8.3, and 9.0
• Swift 3.0, 3.1, 3.2, and 4.0

Communication

• If you found a bug, open an issue.
• If you have a feature request, open an issue.
• If you want to contribute, submit a pull request.

Installation

Manually

If you prefer not to use any dependency managers, you can integrate Transformer into your project manually.

Embedded Framework

• Open up Terminal, cd into your top-level project directory, and run the following command "if" your project is not initialized as a git repository:

  $ git init

• Add Transformer as a git submodule by running the following command:

  $ git submodule add https://github.com/incetro/Transformer.git

• Open the new Transformer folder, and drag the Transformer.xcodeproj into the Project Navigator of your application's Xcode project.

  It should appear nested underneath your application's blue project icon. Whether it is above or below all the other Xcode groups does not matter.

• Select the Transformer.xcodeproj in the Project Navigator and verify the deployment target matches that of your application target.

• Next, select your application project in the Project Navigator (blue project icon) to navigate to the target configuration window and select the application target under the "Targets" heading in the sidebar.

• In the tab bar at the top of that window, open the "General" panel.

• Click on the + button under the "Embedded Binaries" section.

• You will see two different Transformer.xcodeproj folders each with two different versions of the Transformer.framework nested inside a Products folder.

  It does not matter which Products folder you choose from, but it does matter whether you choose the top or bottom Transformer.framework.

• Select the top Transformer.framework for iOS and the bottom one for OS X.

  You can verify which one you selected by inspecting the build log for your project. The build target for Transformer will be listed as either Transformer iOS, Transformer macOS, Transformer tvOS or Transformer watchOS.

• And that's it!

  The Transformer.framework is automagically added as a target dependency, linked framework and embedded framework in a copy files build phase which is all you need to build on the simulator and a device.

Author

incetro, [email protected]

License

Transformer is available under the MIT license. See the LICENSE file for more info.