Add Memento pattern

Author: ivandrofly

Memento/Memento.csproj

@@ -42,12 +42,22 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
-    <Compile Include="Program.cs" />
+    <Compile Include="RealWorld\Memento.cs" />
+    <Compile Include="RealWorld\Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="RealWorld\ProspectMemory.cs" />
+    <Compile Include="RealWorld\SalesProspect.cs" />
+    <Compile Include="Structural\Caretaker.cs" />
+    <Compile Include="Structural\Memento.cs" />
+    <Compile Include="Structural\Originator.cs" />
+    <Compile Include="Structural\Program.cs" />
   </ItemGroup>
   <ItemGroup>
     <None Include="App.config" />
   </ItemGroup>
+  <ItemGroup>
+    <Content Include="Participants.txt" />
+  </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.

Memento/Participants.txt

@@ -0,0 +1,20 @@
+Participants:
+
+ The classes and objects participating in this pattern are:
+
+    Memento  (Memento)
+        stores internal state of the Originator object. The memento may store as much or as little of the originator's
+		internal state as necessary at its originator's discretion.
+        protect against access by objects of other than the originator. Mementos have effectively two interfaces.
+		Caretaker sees a narrow interface to the Memento -- it can only pass the memento to the other objects.
+		Originator, in contrast, sees a wide interface, one that lets it access all the data necessary to restore
+		itself to its previous state. Ideally, only the originator that produces the memento would be permitted
+		to access the memento's internal state.
+
+    Originator  (SalesProspect)
+        creates a memento containing a snapshot of its current internal state.
+        uses the memento to restore its internal state
+
+    Caretaker  (Caretaker)
+        is responsible for the memento's safekeeping
+        never operates on or examines the contents of a memento

Memento/Program.cs

@@ -0,0 +1,41 @@
+namespace DoFactory.GangOfFour.Memento.RealWorld
+{
+    /// <summary>
+    /// The 'Memento' class
+    /// </summary>
+    class Memento
+    {
+        private string _name;
+        private string _phone;
+        private double _budget;
+
+        // Constructor
+        public Memento(string name, string phone, double budget)
+        {
+            this._name = name;
+            this._phone = phone;
+            this._budget = budget;
+        }
+
+        // Gets or sets name
+        public string Name
+        {
+            get { return _name; }
+            set { _name = value; }
+        }
+
+        // Gets or set phone
+        public string Phone
+        {
+            get { return _phone; }
+            set { _phone = value; }
+        }
+
+        // Gets or sets budget
+        public double Budget
+        {
+            get { return _budget; }
+            set { _budget = value; }
+        }
+    }
+}

Memento/RealWorld/Memento.cs

@@ -0,0 +1,58 @@
+using System;
+
+/// <summary>
+/// This real-world code demonstrates the Memento pattern which temporarily saves and then restores the SalesProspect's internal state.
+/// </summary>
+namespace DoFactory.GangOfFour.Memento.RealWorld
+{
+    /// <summary>
+    /// MainApp startup class for Real-World 
+    /// Memento Design Pattern.
+    /// </summary>
+    class MainApp
+    {
+        /// <summary>
+        /// Entry point into console application.
+        /// </summary>
+        static void Main()
+        {
+            SalesProspect s = new SalesProspect();
+            s.Name = "Noel van Halen";
+            s.Phone = "(412) 256-0990";
+            s.Budget = 25000.0;
+
+            // Store internal state
+            ProspectMemory m = new ProspectMemory();
+            m.Memento = s.SaveMemento();
+
+            // Continue changing originator
+            s.Name = "Leo Welch";
+            s.Phone = "(310) 209-7111";
+            s.Budget = 1000000.0;
+
+            // Restore saved state
+            s.RestoreMemento(m.Memento);
+
+            // Wait for user
+            Console.ReadKey();
+
+        }
+
+    }
+}
+
+//Name:   Noel van Halen
+//Phone:  (412) 256-0990
+//Budget: 25000
+
+//Saving state --
+
+//Name:   Leo Welch
+//Phone:  (310) 209-7111
+//Budget: 1000000
+
+//Restoring state --
+
+//Name:   Noel van Halen
+//Phone:  (412) 256-0990
+//Budget: 25000

Memento/RealWorld/Program.cs

@@ -0,0 +1,17 @@
+namespace DoFactory.GangOfFour.Memento.RealWorld
+{
+    /// <summary>
+    /// The 'Caretaker' class
+    /// </summary>
+    class ProspectMemory
+    {
+        private Memento _memento;
+
+        // Property
+        public Memento Memento
+        {
+            set { _memento = value; }
+            get { return _memento; }
+        }
+    }
+}

Memento/RealWorld/ProspectMemory.cs

@@ -0,0 +1,63 @@
+using System;
+
+namespace DoFactory.GangOfFour.Memento.RealWorld
+{
+    /// <summary>
+    /// The 'Originator' class
+    /// </summary>
+    class SalesProspect
+    {
+        private string _name;
+        private string _phone;
+        private double _budget;
+
+        // Gets or sets name
+        public string Name
+        {
+            get { return _name; }
+            set
+            {
+                _name = value;
+                Console.WriteLine("Name:  " + _name);
+            }
+        }
+
+        // Gets or sets phone
+        public string Phone
+        {
+            get { return _phone; }
+            set
+            {
+                _phone = value;
+                Console.WriteLine("Phone: " + _phone);
+            }
+        }
+
+        // Gets or sets budget
+        public double Budget
+        {
+            get { return _budget; }
+            set
+            {
+                _budget = value;
+                Console.WriteLine("Budget: " + _budget);
+            }
+        }
+
+        // Stores memento
+        public Memento SaveMemento()
+        {
+            Console.WriteLine("\nSaving state --\n");
+            return new Memento(_name, _phone, _budget);
+        }
+
+        // Restores memento
+        public void RestoreMemento(Memento memento)
+        {
+            Console.WriteLine("\nRestoring state --\n");
+            this.Name = memento.Name;
+            this.Phone = memento.Phone;
+            this.Budget = memento.Budget;
+        }
+    }
+}

Memento/RealWorld/SalesProspect.cs

@@ -0,0 +1,17 @@
+namespace DoFactory.GangOfFour.Memento.Structural
+{
+    /// <summary>
+    /// The 'Caretaker' class
+    /// </summary>
+    class Caretaker
+    {
+        private Memento _memento;
+
+        // Gets or sets memento
+        public Memento Memento
+        {
+            set { _memento = value; }
+            get { return _memento; }
+        }
+    }
+}

Memento/Structural/Caretaker.cs

@@ -0,0 +1,22 @@
+namespace DoFactory.GangOfFour.Memento.Structural
+{
+    /// <summary>
+    /// The 'Memento' class
+    /// </summary>
+    class Memento
+    {
+        private string _state;
+
+        // Constructor
+        public Memento(string state)
+        {
+            this._state = state;
+        }
+
+        // Gets or sets state
+        public string State
+        {
+            get { return _state; }
+        }
+    }
+}

Memento/Structural/Memento.cs

@@ -0,0 +1,36 @@
+using System;
+
+namespace DoFactory.GangOfFour.Memento.Structural
+{
+    /// <summary>
+    /// The 'Originator' class
+    /// </summary>
+    class Originator
+    {
+        private string _state;
+
+        // Property
+        public string State
+        {
+            get { return _state; }
+            set
+            {
+                _state = value;
+                Console.WriteLine("State = " + _state);
+            }
+        }
+
+        // Creates memento 
+        public Memento CreateMemento()
+        {
+            return (new Memento(_state));
+        }
+
+        // Restores original state
+        public void SetMemento(Memento memento)
+        {
+            Console.WriteLine("Restoring state...");
+            State = memento.State;
+        }
+    }
+}

Memento/Structural/Originator.cs

@@ -0,0 +1,41 @@
+using System;
+
+/// <summary>
+/// This structural code demonstrates the Memento pattern which temporary saves and restores another object's internal state. 
+/// </summary>
+namespace DoFactory.GangOfFour.Memento.Structural
+{
+    /// <summary>
+    /// MainApp startup class for Structural 
+    /// Memento Design Pattern.
+    /// </summary>
+    class MainApp
+    {
+        /// <summary>
+        /// Entry point into console application.
+        /// </summary>
+        static void Main()
+        {
+            Originator o = new Originator();
+            o.State = "On";
+
+            // Store internal state
+            Caretaker c = new Caretaker();
+            c.Memento = o.CreateMemento();
+
+            // Continue changing originator
+            o.State = "Off";
+
+            // Restore saved state
+            o.SetMemento(c.Memento);
+
+            // Wait for user
+            Console.ReadKey();
+        }
+    }
+}
+
+//State = On
+//State = Off
+//Restoring state:
+//State = On