1. UML Extensions for Web Design Design activities: –Partitioning of objects into tiers such as client, server, etc. –Separating and defining user interfaces of Web pages. Web pages serve as generalized user interface containers. Core UML notation does not suffice to express scripted Web pages as objects. Yet they need to coexist with the classes and objects of the system, since they perform important operations. Allocation of web pages to tiers is essential

2. Client Objects and Server Objects Objects having no associations or dependencies with server objects can exist on the client. Candidates for client objects: –UI controls, navigation controls, field validation objects, objects with associations to the browser Candidates for server objects: –Persistent objects, containers, shared objects,objects with associations to databases, …

3. Example: Sequence diagram with Web-Extensions The customer tells the system to check out. The system examines the contents of the shopping cart and produces an itemized list of all the items that are ready to be purchased. The customer confirmes the order and tells the system to process the order. (Conallen, Fig.10-3, p.153)

4. Example: Class diagram with Web- Extensions (Conallen, Fig.10-5, p.156)

5. Example: Expressing scripts in a client page (Conallen, Fig.10-14, p.162) The customer changes the quantity of one of the line items. The customer clicks the recalculate button. The system recalculates the subtotal, tax, and total amount for the order. The new values are displayed in the page.

6. Web-Extensions: Forms Forms are expressed in the model as aggregate of a client page. This object is a collection of standard input elements that accept input from the user and submit it to a server page for processing. Note: for the expression of frames see Conallen 1999, p. 160 Example: Shopping Cart component realizes Shopping Cart classes (Conallen, Fig.10-2, p.149)