TABLE OF CONTENTS The following steps are needed when a system is to be developed as an online application:
Transform the PIM of the system into a PSM oriented to online implementation by determining which entities and associations are to be persistent, ie, stored in a database or some other permanent data storage, and, if a relational database is to be used, transforming the classes and associations to produce a relational database schema.
Identify new entities (often derived directly from the persistent entities) which represent data groups to be entered or presented on web pages. In the case of input data, the entities will have an operation corresponding to the submit action on the web page, this operation should be stereotyped with one of the above standard actions, create, delete, list, etc, if possible. Other operations, such as reset (clear all the text fields to the empty string) may also be present for an entity representing an input form.
Identify invariants of the system: (i) invariants of entities representing web forms express validity criteria for the data input into the form; (ii) invariants of entities representing persistent data correspond to integrity constraints on the database; (iii) invariants linking view and repository data express the functionality of the system, ie, how it responds to submit actions or other client-side actions.
As discussed above, consideration of the interaction between users and the system, and the presentation of information, is particularly critical in the case...
