In this chapter we wrote a complete real-life shopping cart application for mobile devices, using PHP in the middle tier. This illustrates how PHP can be effectively used in the middle tier, to write highly scalable (non-HTML) web-based applications.
To keep the application simple, we chose only minimal features. Some features that you may like to add to this application could include:
An HTML interface to the same application. The HTML site should use the same back-end database. This will allow users to access the same site from their PC browsers as well.
Business workflow logic in the application. For example, sending e-mail to the shipping department after a user has purchased items.
An e-mail confirmation of the order.