swin's Introduction

Swin

How to...

1. Register dependency

1.1 Using class name

Swin.register(type: DemoClassProtocol.self, using: DemoClass.self)

1.2 or, using blocks

Swin.register(type: DemoClassProtocol.self) {
    let instance = DemoClass()
    // do more configurations
    return instance
}

2. Create objects

2.1 With no args

let instanceObject = Swin.create(type: DemoClassProtocol.self)

2.2 or, with args

let instanceObject = Swin.create(type: DemoClassProtocol.self, args: [String: Any]())

3. How are dependencies resolved in above case?

3.1 When using class name to resolve the dependency - the class must implement SwinInitializer protocol. i.e. DemoClass should implement SwinInitializer protocol. For eg.

class DemoClass: DemoClassProtocol, SwinInitializer {
    class func create(_ args: [String : Any]?) -> Any? {
        return DemoClass()
    }
}

3.2 When using block notation to register dependency (1.2) - there is no additional requirement

4. How to replace & restore dependencies?

Swin allows you to create replacement tokens, to temporarily replace a predefined dependency. This is particularly useful when writing tests. In the example below both DemoClass and Democlass2 implements the DemoClassProtocol

Swin.register(type: DemoClassProtocol.self, using: DemoClass.self)

let replaceToken = Swin.replace { dependencies in
    dependencies.add(type: DemoClassProtocol.self) {
    return DemoClass2()
  }
}

let instance1 = Swin.create(type: DemoClassProtocol.self)
// instance1 object is of Type DemoClass2

// call restore() method to undo the replacement
replaceToken.restore()
let instance2 = Swin.create(type: DemoClassProtocol.self)
// instance2 object is of Type DemoClass