Easy ASP.NET Shopping Cart

Sample Image - shopcart.gif

Introduction

If you take a look at my code, you will see that it is not well documented, but I will try and remedy that with this article. The shopping cart object that I will demonstrate here was written by me for use in an ecommerce web page, as part of a library.

Shopping Cart

Let's get right into the object. The following section will create our object. We pass the connection string from the web page so that it is common.

using System;
using System.Data;
using System.Data.OleDb;

namespace Coder2k
{
    public class Cart
    {
        private string strConnection;
        
        public Cart(string conn)
        {
            strConnection = conn;
        }

The following is where our web page will get its cart. We'll demonstrate that later. We use stored procedures so that we can use any database that has an OLE interface and supports stored procedures.

        public OleDbDataReader GetCart(string CartID)
        {
            OleDbConnection conCart = new OleDbConnection(strConnection);
            OleDbCommand comCart = new OleDbCommand("qryGetCart", conCart);
            
            comCart.CommandType = CommandType.StoredProcedure;
            
            OleDbParameter parmCartID = new 
              OleDbParameter("@CartID", OleDbType.VarChar, 50);
            parmCartID.Value = CartID;
            comCart.Parameters.Add(parmCartID);
            
            conCart.Open();
            
            OleDbDataReader result = 
              comCart.ExecuteReader(CommandBehavior.CloseConnection);
            
            return result;
        }

Now, let's look at the rest of it which is very similar to this. Because of stored procedures, we don't need to know anything about the database in this object, which makes it easier to code.

        public void AddItem(string CartID, int ProdID, int Quantity)
        {
            OleDbConnection conItem = new OleDbConnection(strConnection);
            OleDbCommand comItem = new OleDbCommand("qryAddItem", conItem);
            
            comItem.CommandType = CommandType.StoredProcedure;
            
            OleDbParameter parmCartID = new 
              OleDbParameter("@CartID", OleDbType.VarChar, 50);
            parmCartID.Value = CartID;
            comItem.Parameters.Add(parmCartID);
            
            OleDbParameter parmProdID = new 
              OleDbParameter("@ProdID", OleDbType.Integer, 4);
            parmProdID.Value = ProdID;
            comItem.Parameters.Add(parmProdID);
            
            OleDbParameter parmQuant = new 
              OleDbParameter("@Quant", OleDbType.Integer, 4);
            parmQuant.Value = Quantity;
            comItem.Parameters.Add(parmQuant);
            
            conItem.Open();
            comItem.ExecuteNonQuery();
            conItem.Close();
        }
        
        public string GetCartID()
        {
            System.Web.HttpContext context = 
                  System.Web.HttpContext.Current;
            
            if (context.Request.Cookies["West_CartID"] != null)
            {
                return context.Request.Cookies["West_CartID"].Value;
            }
            else
            {
                Guid tempGuid = Guid.NewGuid();
                
                context.Response.Cookies["West_CartID"].Value 
                                             = tempGuid.ToString();
                
                return tempGuid.ToString();
            }
        }
    }
}

Now, the getCartID function is a strange one. It checks to see if the current user has a cart. If they do, it returns that ID, otherwise, it creates a new cart.

Web Pages

I think that the web pages can pretty much speak for themselves if you know ASP web controls. In a later edition of this article, I will explain more on these files, and maybe add some more functionality to the whole thing.