Strategy.md

Introduction

Design Patterns that will be covered in this article:

• Strategy

Strategy

This design pattern defines a family of interchangeable objects that can be set or switched at runtime. Also, Strategy is categorized under Behavioral patterns because the Strategy pattern is ultimately about 1 object using another to do something.

This pattern has 3 parts in-total:

• The object using a strategy (typically, a view controller in an iOS app)
• The Strategy Protocol
  • This protocol defines methods that every strategy must implement
• The strategies are objects that conform to the Strategy Protocol

When Should You Use It?

1. Use the strategy pattern when you have 2 or more different interchangeable behaviors
2. Unlike Delegation, the strategy pattern defines a family of objects
3. Strategies are intended to be easily changeable at runtime whereas Delegation are often fixed at runtime

Code

AnimeViewController.swift

AnimeDetailViewController.swift

AttackOnTitansStrategy.swift

SwordArtOnlineStrategy.swift

AnimeView.swift

AnimeDetailView.swift

Main.storyboard

Finished Project

What Should You be Careful About?

• Be careful about pre-optimizing and overusing this pattern.
• If a behavior won't ever change, it's perfectly okay to code it in a controller / object.