Explanation of Template Design Pattern

Let's begin.

• AbstractClass defines the algorithm and what operations do we need for ConcreteClass. In here we define the template of the operations.
• ConcreteClass implements the the step operations of different type of algorithms according to Abstract Class template.

Before we start the example you should take a look at below article. I used somethings within this article : Type Class and typeof Keyword and GetType in C#

In our example we are going to make different types of soups. Almosts every soups have same mixtures : Tomatoes, paste, onions and water. The other elements are changing according to kind of soups.

First I have to create my abstract class. In this class I will have my abstract and virtual methods to get a soup ready. After I will derive soup classes from this abstract class.

Soup.cs

using System;

namespace TemplatePattern_Example
{
    public abstract class Soup
    {
        //My abstract methods
        public abstract void AddMaterials();
        public abstract void CookSoup();

        //My virtual method
        public virtual void AddSpecialMaterial(string specialMaterial)
        {
            Console.WriteLine("The Special material " + specialMaterial + " for " + GetType().Name + " has been added");
        }

        //My get Ready method.
        public void GetSoupReady()
        {
            AddMaterials();
            CookSoup();

            Console.WriteLine(GetType().Name + " is ready... Enjoooy :)");
            Console.WriteLine("-----------------------------" + Environment.NewLine);
        }
    }
}

Now I need to derive the sub classes which perform the specific operations. Below code blocks you will see my sub classes.

TomatoSoup.cs

using System;

namespace TemplatePattern_Example
{
    class TomatoSoup : Soup
    {
        public override void AddMaterials()
        {
            Console.WriteLine("Adding Essential Materials for Tomato Soup...");
        }

        public override void CookSoup()
        {
            Console.WriteLine("Tomato Soup is cooking...");
        }
    }
}

ChickenSoup.cs

using System;

namespace TemplatePattern_Example
{
    class ChickenSoup : Soup
    {
        public override void AddMaterials()
        {
            Console.WriteLine("Adding Essential Materials for Chicken Soup...");
            //I also add some other materials except the main materials
            AddSpecialMaterial("Delicious Chicken meat");
        }

        public override void CookSoup()
        {
            Console.WriteLine("Chicken Soup is cooking...");
        }
    }
}

EzoGelinSoup.cs

using System;

namespace TemplatePattern_Example
{
    class EzoGelinSoup : Soup
    {
        public override void AddMaterials()
        {
            Console.WriteLine("Adding Materials for EzoGelin Soup...");
            //I also add some other materials except the main materials
            AddSpecialMaterial("Lentils");
        }

        public override void CookSoup()
        {
            Console.WriteLine("EzoGelin Soup is cooking...");
        }
    }
}

OnionSoup.cs

using System;

namespace TemplatePattern_Example
{
    class OnionSoup : Soup
    {
        public override void AddMaterials()
        {
            Console.WriteLine("Adding Materials for Onion Soup...");
        }

        public override void CookSoup()
        {
            Console.WriteLine("Onion Soup is cooking...");
        }
    }
}

Program.cs

using System;

namespace TemplatePattern_Example
{
    class Program
    {
        static void Main(string[] args)
        {
            TomatoSoup tomSoup = new TomatoSoup();
            tomSoup.GetSoupReady();

            ChickenSoup chickSoup = new ChickenSoup();
            chickSoup.GetSoupReady();

            EzoGelinSoup ezoSoup = new EzoGelinSoup();
            ezoSoup.GetSoupReady();

            OnionSoup onionSoup = new OnionSoup();
            onionSoup.GetSoupReady();

            Console.ReadLine();
        }
    }
}

That is all in this article.

You can reach the example on Github : https://github.com/thecodeprogram/TemplatePattern_Example

Now you are good to use the Template Design pattern in your projects.

I wish you healthy days.

Burak Hamdi TUFAN.