Created
June 20, 2021 19:58
-
-
Save ArisAgnew/30c9e7d7bdb8d272cc70c632539e5ed4 to your computer and use it in GitHub Desktop.
Refactoring If-Else to State Design Pattern
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
//If-Else Approach | |
public enum Reaction | |
{ | |
Initial = 1, | |
Liked = 2, | |
Disliked = 3 | |
} | |
public class LikeDislikeComponent | |
{ | |
public Reaction Current { get; private set; } = Reaction.Initial; | |
public int Likes { get; private set; } | |
public int Dislikes { get; private set; } | |
public void Like() | |
{ | |
if (Current == Reaction.Initial) | |
{ | |
Likes++; | |
Current = Reaction.Liked; | |
} | |
else if (Current == Reaction.Liked) | |
{ | |
Likes--; | |
Current = Reaction.Initial; | |
} | |
else if (Current == Reaction.Disliked) | |
{ | |
Dislikes--; | |
Likes++; | |
Current = Reaction.Liked; | |
} | |
} | |
public void Dislike() | |
{ | |
if (Current == Reaction.Initial) | |
{ | |
Dislikes++; | |
Current = Reaction.Disliked; | |
} | |
else if (Current == Reaction.Liked) | |
{ | |
Likes--; | |
Dislikes++; | |
Current = Reaction.Disliked; | |
} | |
else if (Current == Reaction.Disliked) | |
{ | |
Dislikes--; | |
Current = Reaction.Initial; | |
} | |
} | |
} | |
//State Design Pattern | |
namespace LikesDislikes | |
{ | |
using System; | |
public class LikeDislikeComponent | |
{ | |
//constructors | |
public LikeDislikeComponent(ILikeDislikeComponentState state) | |
{ | |
_currentState = state; | |
} | |
public LikeDislikeComponent( | |
int likesCount, | |
int dislikesCount, | |
ILikeDislikeComponentState state) : this (state) | |
{ | |
LikesCount = likesCount; | |
DislikesCount = dislikesCount; | |
} | |
//private properties | |
private ILikeDislikeComponentState _currentState; | |
//public properties | |
public int LikesCount { get; set; } | |
public int DislikesCount { get; set; } | |
//methods | |
public void ChangeState(ILikeDislikeComponentState state) => _currentState = state; | |
public void Like() => _currentState.Like(this); | |
public void Dislike() => _currentState.Dislike(this); | |
} | |
public interface ILikeDislikeComponentState | |
{ | |
void Like(LikeDislikeComponent component); | |
void Dislike(LikeDislikeComponent component); | |
} | |
public class InitialState : ILikeDislikeComponentState | |
{ | |
public void Like(LikeDislikeComponent component) | |
{ | |
component.LikesCount++; | |
component.ChangeState(new LikedState()); | |
} | |
public void Dislike(LikeDislikeComponent component) | |
{ | |
component.DislikesCount++; | |
component.ChangeState(new DislikedState()); | |
} | |
} | |
public class LikedState : ILikeDislikeComponentState | |
{ | |
public void Like(LikeDislikeComponent component) | |
{ | |
component.LikesCount--; | |
component.ChangeState(new InitialState()); | |
} | |
public void Dislike(LikeDislikeComponent component) | |
{ | |
component.LikesCount--; | |
component.DislikesCount++; | |
component.ChangeState(new DislikedState()); | |
} | |
} | |
public class DislikedState : ILikeDislikeComponentState | |
{ | |
public void Like(LikeDislikeComponent component) | |
{ | |
component.DislikesCount--; | |
component.LikesCount++; | |
component.ChangeState(new LikedState()); | |
} | |
public void Dislike(LikeDislikeComponent component) | |
{ | |
component.DislikesCount--; | |
component.ChangeState(new InitialState()); | |
} | |
} | |
class Program | |
{ | |
static void Main() | |
{ | |
var component = new LikeDislikeComponent(34, 5, new InitialState()); | |
component.Like(); //Likes: 35, Dislikes 5 | |
component.Like(); //Likes: 34, Dislikes 5 | |
component.Dislike(); //Likes: 34, Dislikes 6 | |
component.Dislike(); //Likes: 34, Dislikes 5 | |
component.Like(); //Likes: 35, Dislikes 5 | |
} | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment