Swift adapter design sample – The.Swift.Dev.

Fist of all let me emphasize that, that is the true world illustration of what we’ll construct on this little Swift adapter sample tutorial:

Adapter is a structural design sample that enables objects with incompatible interfaces to work collectively. In different phrases, it transforms the interface of an object to adapt it to a distinct object.

So adapter can remodel one factor into one other, typically it is referred to as wrapper, as a result of it wraps the item and offers a brand new interface round it. It is like a software program dongle for particular interfaces or legacy courses. (Dongle haters: it is time to depart the previous behind!) 😂

Adapter design sample implementation

Creating an adapter in Swift is definitely a brilliant straightforward job to do. You simply must make a brand new object, “field” the outdated one into it and implement the required interface in your new class or struct. In different phrases, a wrapper object will probably be our adapter to implement the goal interface by wrapping an different adaptee object. So once more:

Adaptee

The item we’re adapting to a selected goal (eg. old-school USB-A port).

Adapter

An object that wraps the unique one and produces the brand new necessities specified by some goal interface (this does the precise work, aka. the little dongle above).

Goal

It’s the object we wish to use adaptee with (our USB-C socket).

How one can use the adapter sample in Swift?

You should utilize an adapter if you wish to combine a third-party library in your code, nevertheless it’s interface does not match together with your necessities. For instance you possibly can create a wrapper round a whole SDK or backend API endpoints in an effort to create a typical denominator. 👽

In my instance, I will wrap an EKEvent object with an adapter class to implement a model new protocol. 📆

import Basis
import EventKit


protocol Occasion {
    var title: String { get }
    var startDate: String { get }
    var endDate: String { get }
}


class EventAdapter {

    personal lazy var dateFormatter: DateFormatter = {
        let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = "yyyy. MM. dd. HH:mm"
        return dateFormatter
    }()

    personal var occasion: EKEvent

    init(occasion: EKEvent) {
        self.occasion = occasion
    }
}


extension EventAdapter: Occasion {

    var title: String {
        return self.occasion.title
    }
    var startDate: String {
        return self.dateFormatter.string(from: occasion.startDate)
    }
    var endDate: String {
        return self.dateFormatter.string(from: occasion.endDate)
    }
}


let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "MM/dd/yyyy HH:mm"

let calendarEvent = EKEvent(eventStore: EKEventStore())
calendarEvent.title = "Adapter tutorial deadline"
calendarEvent.startDate = dateFormatter.date(from: "07/30/2018 10:00")
calendarEvent.endDate = dateFormatter.date(from: "07/30/2018 11:00")


let adapter = EventAdapter(occasion: calendarEvent)

One other use case is when it’s important to use a number of present ultimate courses or structs however they lack some performance and also you wish to construct a brand new goal interface on prime of them. Generally it is a sensible choice to implement an wrapper to deal with this messy state of affairs. 🤷‍♂️

That is all concerning the adapter design sample. Often it is very easy to implement it in Swift – or in every other programming language – nevertheless it’s tremendous helpful and typically unavoidable. Children, bear in mind: do not go too onerous on dongles! 😉 #himym