ARTICLE

Let's Play Around With Facade Pattern - Design Pattern

Posted by Vijay Prativadi Articles | C# Language April 16, 2012
Today, in this article let's play around with an interesting and one of the most useful concepts of design pattern, which will be hosted in a web app.
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Introduction

Today, in this article let's play around with an interesting and one of the most useful concepts of design pattern, which will be hosted in a web app.

Question:
What is Facade Pattern?

In simple terms "It acts as a single set of unified wrappers for multiple complex classes, it wraps a bunch of complex classes into a single unique facade pattern class. By doing this we can minimize complexity faced when code keeps growing and growing. It provides a more sophisticated look when even looked at class diagram and easy understandability ".

The diagrammatic representation of the Facade Pattern - Design Pattern for this application looks like this:

Image1.png

I think we are now good to go to implement this wonderful concept.

Step 1:
The complete code of Default.aspx looks like this:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="FacadePatternApplication._Default" %>
 
<! DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title></title>
</head>
<
body>
    <form id="form1" runat="server">
    <div>
        <h1 style="text-align: center; font-family: Verdana; font-size: large; color: Maroon">
            Facade Pattern - Design Patterns</h1>
        <center>
            <table
                <tr>
                    <td>
                        <asp:Label ID="Label1" runat="server" Text="Please Enter First Number" Font-Size="Small"
                            Font-Bold="true" Font-Italic="true" Font-Names="Verdana"></asp:Label>
                    </td>
                    <td>
                        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
                    </td>
                </tr>
                <tr>
                    <td>
                        <asp:Label ID="Label2" runat="server" Text="Please Enter Second Number" Font-Size="Small"
                            Font-Bold="true" Font-Italic="true" Font-Names="Verdana"></asp:Label>
                    </td>
                    <td>
                        <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
                    </td>
                </tr>
                <tr>
                    <td colspan="2">
                        <asp:Button ID="Button1" runat="server" Text="Addition / Subtraction" Width="165px"
                            Font-Names="Verdana" BackColor="Orange" OnClick="Button1_Click" />
                    </td>
                </tr>
                <tr>
                    <td colspan="2">
                        <asp:Button ID="Button2" runat="server" Text="Multiply / Divide" Width="165px" Font-Names="Verdana"
                            BackColor="Orange" OnClick="Button2_Click" />
                    </td>
                </tr>
            </table>
            <table>
                <tr>
                    <td colspan="2">
                        <asp:Label ID="lblResult" runat="server" Font-Names="Verdana" ForeColor="Brown"></asp:Label>
                    </td>
                </tr>
                <tr>
                    <td colspan="2">
                        <asp:Label ID="lblResult1" runat="server" Font-Names="Verdana" ForeColor="Brown"></asp:Label>
                    </td>
                </tr>
            </table>
        </center>
    </div>
    </form>
</body>
</
html>

Step 2: The complete code of PartialAddClass.cs looks like this:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace FacadePatternApplication
{
    public class PartialAddClass
    {
        public double Add(double a, double b)
        {
            return a + b;
        }
    }
}

Step 3: The complete code of PartialSubClass.cs looks like this:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace FacadePatternApplication
{
    public class PartialSubClass
    {
        public double Sub(double a, double b)
        {
            return a - b;
        }
    }
}

Step 4: The complete code of PartialMulClass.cs looks like this:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace FacadePatternApplication
{
    public class PartialMulClass
    {
        public double Mul(double a, double b)
        {
            return a * b;
        }
    }
}


Step 5:
The complete code of PartialDivClass.cs looks like this:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace FacadePatternApplication
{
    public class PartialDivClass
    {
        public double Div(double a, double b)
        {
            return a / b;
        }
    }
}


Step 6: The complete code of Default.aspx.cs looks like this:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using WebApplication3;
 
namespace FacadePatternApplication
{
    public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
        }
        protected void Button1_Click(object sender, EventArgs e)
        {
            if (string.IsNullOrEmpty(TextBox1.Text) || string.IsNullOrEmpty(TextBox2.Text))
            {
                lblResult.Text = "Please Enter Some Values"; lblResult1.Text = "";
            }
            else
            {
                AddSub(); TextBox1.Text = ""; TextBox2.Text = "";
            }
        }
        protected void Button2_Click(object sender, EventArgs e)
        {
            if (string.IsNullOrEmpty(TextBox1.Text) || string.IsNullOrEmpty(TextBox2.Text))
            {
                lblResult.Text = "Please Enter Some Values"; lblResult1.Text = "";
            }
            else
            {
                MulDiv(); TextBox1.Text = ""; TextBox2.Text = "";
            }
        }
        public void AddSub()
        {
            lblResult.Text= "Addition Result is <b>"+objAdd.Add(Convert.ToDouble(TextBox1.Text),
                Convert.ToDouble(TextBox2.Text))+"</b></br>";
            lblResult1.Text = "Subtraction Result is <b>" + objSub.Sub(Convert.ToDouble(TextBox1.Text),
                Convert.ToDouble(TextBox2.Text)) + "</b></br>";
        }
        public void MulDiv()
        {
            lblResult.Text = "Multiplication Result is <b>" + objMul.Mul(Convert.ToDouble(TextBox1.Text),
                Convert.ToDouble(TextBox2.Text)) + "</b></br>";
            lblResult1.Text = "Division Result is <b>" + objDiv.Div(Convert.ToDouble(TextBox1.Text),
                Convert.ToDouble(TextBox2.Text)) + "</b></br>";
        }
        #region Instance Variables PartialAddClass objAdd = new PartialAddClass();
        PartialSubClass objSub = new PartialSubClass();
        PartialMulClass objMul = new PartialMulClass();
        PartialDivClass objDiv = new PartialDivClass();
        #endregion
    }
}

Step 7: The output of the application looks like this:

Output1.png

Step 8: The output of the nothing entered application looks like this:

Output2.png

Step 9: The output of the addition/subtraction operation application looks like this:

Output3.png
Output4.png

Step 10: The output of the multiplication/division operation application looks like this:

Output5.png

I hope this article is useful for you. I look forward for your comments and feedback. Thanks Vijay Prativadi

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