The simplest web shop

Suppose you wanted to develop a web shop. We can build on some tried and true patterns, our imagination, and some existing open source tools.

A basic web shop development story

Minimally we need:

• Customer information {customer number, title, first name, last name, street, number, zipcode (many formats depending on residence), place of residence, country, phone number, email address, password}
• Product information {product number, product name, price}
• Order {number ordered, order number, order date}
• Ordering {order number, product number, number ordered}

And around these, we need at least one shop window that displays products with a handle for customers to add products to their shopping cart, and that the shop manager can remove a product or add to (using cookies, session or temporary table as transport medium).

When looking in the shopping cart, the customer can see all products and prices in an overview including taxes and shipping costs, if applicable.

Oh, and we need a checkout. Our checkout interfaces to payment gateways. This is never going to be a straightforward thing to do and it is important that when signing up to a gateway service we are sure that they can interface to the software we use, if any.

Payment gateways are great because the sale goes through (almost) instantly, and both web shop manager and customer receive feedback that the payment has been received. Processing payments off-line is the simplest gateway: the customer’s credit card details are sent to the web shop manager who then proceeds further using off-line payment interfaces in his/her own time.

And I can easily imagine some next refinement stories …

• Including price in ordering, so that when the web shop manager changes the price of a product, existing orders (made before the price was changed) maintain the old price.
• Have a separate delivery and payment address. This makes gifting possible, and corporate customers will also be thrilled.
• Add the address to Order, so that when customers move and address changes, the historical data remains intact (is not rewritten).
• Addition of stock overview
• Category products in separate shop windows
• Do more than the above …

More on web shops

• Payment gateways
• More to follow on mash-ups and plug-ins …