Template Method

Template Method

The Template Method is know as a behavioral pattern which lets subclasses implement behaviour that can vary. In the example below we use the Template Method to allow sub classes to implement how a hot drink is made.

A VB example of the Temple Method Pattern

Public Class MyPage
          Public Sub Page_Load()
     
        Dim CupOfTea As HotDrink
        CupOfTea = New Tea

        Dim CupOfCoffee As HotDrink
        CupOfCoffee = New Coffee

        MakeDrink(CupOfTea)        

        Response.write(".........<br/>")

        MakeDrink(CupOfCoffee)

     End Sub
     ''' <summary>
     ''' Generic Method that will make the hot Drink
     ''' </summary>
     Public Sub MakeDrink(ByVal HotDrink As HotDrink)
      
        HotDrink.boilWater()
        HotDrink.addIngredients()
        HotDrink.addCondiments()
     End SubEnd Class
''' <summary>''' Abstract Class
''' </summary>Public MustInherit Class HotDrink

     Public Sub boilWater()
          Response.write("Boiling Water...<br/>")
     End Sub
     Public MustOverride Sub addIngredients()

     Public MustOverride Sub addCondiments()End Class
''' <summary>''' Tea Class that implements behaviour that can vary i.e.
''' the addIngredients & addCondiments methods
''' </summary>Public Class Tea
     Inherits HotDrink

     Public Overrides Sub addCondiments()
         Response.write("Add Milk ...<br/>")
     End Sub
     Public Overrides Sub addIngredients()
         Response.write("Add Tea Bags ...<br/>")
     End SubEnd Class
''' <summary>''' Coffee Class that implements behaviour that can vary i.e.
''' the addIngredients & addCondiments methods
''' </summary>Public Class Coffee
     Inherits HotDrink

     Public Overrides Sub addCondiments()
         Response.write("Add Milk ...<br/>")
     End Sub
     Public Overrides Sub addIngredients()
         Response.write("Add Coffee Granules ...<br/>")
     End Sub
End Class

UML