ProductReview Example

ProductReview Example page under construction

Introduction

This is an example of how to create a AJAX solution using Visual DataFlex.

In this example the overall goal is to be able to see what users think about a particular item . As an added benefit - users can also share information about where to buy the particular items.

To accomplish this, then users should be able to:

• login
• choose an item from a list (use a AJAX Lookup List )
• enter information about a known item ( AJAX Form )
• supply information about the place where an item was bought.
• supply a rating of an item
• Overview supplied ratings from other users

Data Dictionaries

We want to store information about users, places and known items. The other tables should hold sufficient information about the items and how the users liked them.

The following data dictionaries should now be available:

Address

• Place_id
• Name
• StreetAddress
• City
• ZIPCode
• Longitude
• latitude

User

• User_id
• LoginName
• FirstName
• LastName
• EmailAddress
• Address_id
• Rights (system user?)

Shop

• Shop_id
• Name
• Description
• Address_id

Item

• Item_id
• Name
• Description
• Manufacturer
• Price

Rating

• Item_Id
• User_id
• Rating
• Comment

VDF Ajax implementation

The implementation will be split up into Data Dictionaries, Web Service Objects and web markup . All of these should be familiar to you if you have taken the time to look at the other examples in the VDF Ajax library

Web Service objects

Create a AJAX WebService Object to call from the clientside VDF Ajax lib. This webservice will be responsible for handling the serverside calls.

The Web Service object should provide the following functionality for session management.

• UserLogin: checking if the supplied password is correct. Use User_DD
• HasRights: does the logged in user have the rights to perform the chosen function. Use User_DD

The HasRights function should identify whether the user is administrator or not.

Web Browser Objects

• SessionManager.wo: Handle session related information
• item.wo : handling information about items.
• user.wo : handling information about users
• place.wo: handling info about places
• purchase.wo: handle information about places
• rating.wo: handle information about ratings

The Web Object should use the corresponding data dictionaries

Access restrictions

"ordinary" users should only be allowed to alter information about themselves - e.g "Joe" should not be allowed to alter the address of "Bob". only "Administrators" should be allowed to add new products and places to the database. E.g "Joe" should not be able to add all his favourite places and products to the list. "Ordinary" users should only be able to rate an item allready in the system .

Web markup

The web markup should be designed around forms, that evolve around the web objects.

• login.asp: a page showing a login box
• frontpage.asp: display a greeting after a successfull login
• Rating.asp: a list of items with detailed ratings. show details about related users and items.
• Item.asp: Information about an item
• Shop.asp: information about a place where items can be bought ( AJAX Form )
• User.asp: Informaation about usres