Lesson6

ShoppingExample/ConsoleApp/ConsoleApp.csproj

@@ -7,4 +7,8 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\ProductsLib\ProductsLib.csproj" />
+  </ItemGroup>
+
 </Project>

ShoppingExample/ConsoleApp/Program.cs

@@ -1,4 +1,8 @@
 using System;
+using System.Reflection.Metadata.Ecma335;
+using ProductsLib;
+using ProductsLib.Clothing;
+using ProductsLib.Electronics;
 
 class Program
 {
@@ -7,7 +11,10 @@ static void Main(string[] args)
         var mansShirt = new MansShirt(
             "FormalShirt",
             "Smart white shirt for business meetings",
-            Price.Pounds(25.0)
+            Price.Pounds(25.0),
+            "Leather",
+            "Winter",
+            true
             );
 
         var laptop = new Laptop(
@@ -16,6 +23,8 @@ static void Main(string[] args)
             Price.Euros(999.99)
             );
 
+
+
         // Homework: create more products of different types, priced in different currencies,
         // and some power tools that work in different countries
 
@@ -53,203 +62,3 @@ private static void DisplayTheMostExpensiveProduct(Product[] products)
     }
 
 }
-
-// Product is something we can buy/sell
-// it's abstract. Why?
-// Product has a Price, a Name, a Description
-//
-public abstract class Product
-{
-    // Homework: Name, Description, Price are properties. Find out about this, and learn how
-    // a property combines a field and a method. Also, find out what "init" means here.
-    public string Name { get; init; }
-    public string Description { get; init; }
-    public Price Price { get; init; }
-    public Product(string name, string description, Price price)
-    {
-        Name = name;
-        Description = description;
-        Price = price;
-    }
-}
-
-
-// We want to sell our products to many countries, so
-// Price needs both a number and a currency.
-// We might be using Price a lot in many functions and these functions
-// might be called many times. It's a small object though (how many bytes?)
-// so what is the best way to represent it? a stack object or a heap object?
-public struct Price
-{
-    public double Amount { get; init; }
-    public string Currency { get; init; }
-    private Price(double amount, string currency)
-    {
-        Amount = amount;
-        Currency = currency;
-    }
-    // Homework: how does the factory method pattern help you to make
-    // sure that Price objects are always created correctly with currency names that are valid?
-    public static Price Pounds(double amount)
-    {
-        // Homework, throw exception if amount is negative
-        return new Price(amount, "GBP");
-    }
-
-    public static Price Euros(double amount)
-    {
-        // Homework, throw exception if amount is negative
-        return new Price(amount, "EUR");
-    }
-
-    // Homework: add more factory methods for other currencies like USD, CAD, AUD, JPY, etc.
-
-}
-
-// The first layer of derived classes are high level categories like
-// Electronics, Clothing, Food, Tools, Motor Vehicles even Services and Vouchers
-// These are still abstract classes because we can't create one without knowing
-// exactly what it is
-public abstract class Electronics : Product
-{
-    public Electronics(string name, string description, Price price)
-        : base(name, description, price)
-    {
-    }
-}
-public abstract class Clothing : Product
-{
-    public Clothing(string name, string description, Price price)
-        : base(name, description, price)
-    {
-    }
-}
-public abstract class Food : Product, IHasExpiryDate
-{
-    // Homework: what does "DateTime? expiryDate = null" mean?
-    public Food(string name, string description, Price price, DateTime? expiryDate = null)
-        : base(name, description, price)
-    {
-        // Homework: what does this line do? What does "??" mean?
-        ExpiryDate = expiryDate ?? DateTime.MaxValue;
-    }
-
-    // Homework: notice that the ExpiryDate property was declared on the
-    // interface and has to be implemented here (just like abstract methods)
-    public DateTime ExpiryDate { get; set; }
-}
-public abstract class Tools : Product
-{
-    public Tools(string name, string description, Price price)
-        : base(name, description, price)
-    {
-    }
-}
-public abstract class MotorVehicles : Product
-{
-    public MotorVehicles(string name, string description, Price price)
-        : base(name, description, price)
-    {
-    }
-}
-public abstract class Services : Product, IPhysicalOrDigital
-{
-    public Services(string name, string description, Price price, bool isDigital = false)
-        : base(name, description, price)
-    {
-        IsDigital = isDigital;
-    }
-
-    public bool IsDigital { get; init ; }
-}   
-public abstract class Vouchers : Product, IHasExpiryDate, IPhysicalOrDigital
-{
-    public Vouchers(string name, string description, Price price, DateTime? expiryDate, bool isDigital = true)
-        : base(name, description, price)
-    {
-        IsDigital = isDigital;
-    }
-
-    // Homework: implement this property from the interface
-    public DateTime ExpiryDate { 
-        get => throw new NotImplementedException(); 
-        set => throw new NotImplementedException(); 
-    }
-    public bool IsDigital { get; init; }
-}
-
-//
-// In clothing, we have Mens and Womens (still abstract!)
-//
-public abstract class MensClothing : Clothing
-{
-    public MensClothing(string name, string description, Price price)
-        : base(name, description, price)
-    {
-    }
-}
-public abstract class WomensClothing : Clothing
-{
-    public WomensClothing(string name, string description, Price price)
-        : base(name, description, price)
-    {
-    }
-}
-
-// Finally, we have concrete classes that we can instantiate
-// For example, in MensClothing, we have Shirts and MansTrousers
-// and in Electronics we have Phones and Laptops
-public class MansShirt : MensClothing
-{
-    public MansShirt(string name, string description, Price price)
-        : base(name, description, price)
-    {
-    }
-}
-public class MansTrousers : MensClothing
-{
-    public MansTrousers(string name, string description, Price price)
-        : base(name, description, price)
-    {
-    }
-}
-public class Phone : Electronics
-{
-    public Phone(string name, string description, Price price)
-        : base(name, description, price)
-    {
-    }
-}
-public class Laptop : Electronics
-{
-    public Laptop(string name, string description, Price price)
-        : base(name, description, price)
-    {
-    }
-}
-
-// Homework
-// 1. Add more concrete product classes like WomensClothing, Food items, Motor Vehicles
-// 2. Tools can be power tools or hand tools. Create classes for these. Abstract or not?
-// 3. Power tools only work in certain countries because of voltage differences and plug shapes.
-//    How would you represent this in your class design? You need to tell the customer whether
-//    the power tool will work in "UK", "USA/CANADA", "EUROPE", etc.
-// 4. Look at the interface I have specified below for items that have an expiry date, like Food or Vouchers.
-//    Some Foods need to be eaten before expiry date, and Vouchers sometimes need to be used before expiry date.
-
-public interface IHasExpiryDate
-{
-    DateTime ExpiryDate { get; set; }
-}
-
-// Vouchers and Services can be provided physically or digitally, so they implement this interface
-public interface IPhysicalOrDigital
-{
-    bool IsDigital { get; init; }
-}
-
-// 5. Look at the Vouchers class. Notice it inherits from Product but also implements more than
-//    one interface. This is the big difference between classes and interfaces in C#. If using only
-//    classes, we would have to use single inheritance, which means the structure can only be a tree.
-//    But with interfaces, we can implement multiple interfaces, so the structure can be a graph.
-//    Real life products are more like a graph than a tree!

ShoppingExample/ExtensionMethodTests/ExtensionMethodTests.csproj

@@ -0,0 +1,28 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="coverlet.collector" Version="6.0.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
+    <PackageReference Include="NUnit" Version="3.14.0" />
+    <PackageReference Include="NUnit.Analyzers" Version="3.9.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.5.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\ProductsLib\ProductsLib.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="NUnit.Framework" />
+  </ItemGroup>
+
+</Project>