Joy of Patterns: Using Patterns for Enterprise Development, The

Solution

Let's consider a simple framework to allow additional prices for a setup and reconfiguration by parts. We would also like to be able to display a description/invoice of parts. This framework will be more than a simple select from a product list; it should allow us to ensure that a valid configuration is built. Let's start by considering the major entities:

Parts: A part is an entity that may be sold.

1. All parts consume and provide resources.

2. All parts have a name.

3. All parts have a description.

4. All parts have a price (either fixed or set by an algorithm).

5. Complex parts may be composed of other parts.

Resources: A resource is any entity that is provided or consumed by a part.

1. A resource has a name.

2. A resource has a quantity.

Configuration: