Composite Design Pattern - Structural

A tree (family / recipe) structure of simple and composite objects. A composite is an object designed as a composition of one-or-more similar objects, all exhibiting similar functionality.

Sample Code Download: CompositeDesignPattern.zip (Visual Studio 2017 Console App)

Interface IEmpoyee

Create an interface IEmployee

//Component
public interface IEmployee
{
    void GetDetails(int indentation);
}

Employee Class

Create Employee Class and implement the interface component

public class Employee : IEmployee
{
    public Employee(string name, string dept)
    {
        this.Name = name;
        this.Department = dept;
    }

    public string Name { get; set; }
    public string Department { get; set; }

    public void GetDetails(int indentation)
    {
        Console.WriteLine(
            $"{new String('-', indentation)}- Name:{Name.ToString()}, Dept:{Department} (Leaf) "
        );
    }
}

Manager Class

Create Manager Class which is the composite and implement the interface component and add the subordinates as shown below.

public class Manager : IEmployee
{
    public List SubOrdinates;

    public Manager(string name, string dept)
    {
        this.Name = name;
        this.Department = dept;
        SubOrdinates = new List();
    }

    public string Name { get; set; }
    public string Department { get; set; }

    public void GetDetails(int indentation)
    {
        Console.WriteLine();
        Console.WriteLine($"{new String('-', indentation)}+ Name:{this.Name.ToString()}, " +
                          $"Dept:{this.Department} - Manager(Composite)");
        foreach (var component in SubOrdinates)
        {
            component.GetDetails(indentation + 1);
        }
    }
}

Main

Switch to the client which is main program and implement the below code

class Program
{
    static void Main(string[] args)
    {
        IEmployee john = new Employee("John", "IT");
        IEmployee mike = new Employee("Mike", "IT");
        IEmployee jason = new Employee("Jason", "HR");
        IEmployee eric = new Employee("Eric", "HR");
        IEmployee henry = new Employee("Henry", "HR");

        IEmployee james = new Manager("James", "IT") { SubOrdinates = { john, mike } };

        IEmployee philip = new Manager("Philip", "HR") { SubOrdinates = { jason, eric, henry } };

        //bob is managers manager
        IEmployee bob = new Manager("Bob", "Head") { SubOrdinates = { james, philip } };
        bob.GetDetails(1);

        //print james and its leafs
        james.GetDetails(1);
       
        Console.ReadLine();
    }
}

Structural Design Patterns   Adapter | Bridge | Composite | Decorator | Facade | Flyweight | Proxy