B118 Web Programming

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B118 Web Programming

• IBuySpy.com Shopping Cart Mechanism

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IBuySpy.com Store

• http//cypress.cob.sjsu.edu/storevb
• Documentation http//cypress.cob.sjsu.edu/storevb
  /docs/docs.htm
• Well be concentrating on the Shopping Cart
  architecture topic

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ShoppingCartDB Class Methods

• GetItems(ByVal cartID As String) As
  OleDbDataReader
• AddItem(ByVal cartID As String, ByVal productID
  As String, ByVal quantity As Integer)
• UpdateItem(ByVal cartID As String, ByVal
  productID As String, ByVal quantity As Integer)
• RemoveItem(ByVal cartID As String, ByVal
  productID As String)
• GetItemCount(ByVal cartID As String) As Integer

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ShoppingCartDB Class Methods (contd)

• GetTotal(ByVal cartID As String) As Decimal
• MigrateCart(ByVal oldCartId As String, ByVal
  newCartId As String)
• EmptyCart(ByVal cartID As String)
• GetShoppingCartId() As String
• GetProductQty(ByVal cartID As String, ByVal
  productID As String) As Integer
• bEssentials addition

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Shopping Cart Implementation Architecture
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Why a separate set of routines?

• Improves maintainability
• Separates UI from Business Components
• Web page code contains very little database code,
  makes it easier to read
• Database code can be changed without affecting
  web page code
• Example Fall 2003 re-architecting to use
  ShoppingCartConnectionString
• Stored procedures isolates SQL-specific
  instructions
• Makes Business Components database-independent
• Prevents SQL-injection hacking

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Comparison of the two shopping cart mechanisms

• Previous cookie-based
• Cart contents accessible only from the same
  machine
• Has the potential to disappear over time
• Private contents, accessible only when user views
  web site
• Server-platform independent
• Now database-driven
• Cart contents accessible from different machines
• Permanent
• Server operator can view contents without users
  knowledge
• Coding depends on server environment