Security - Beginning Oracle Application Express 4.2 - page 234

Running the application now shows the results in Figure 9-8 for the Issue Tracker tab and Figure 9-9 for the
Admin tab. The page that is currently active changes the highlight applied to the different tab elements. The parent tab
location is dependent on the template used. In the template shown here, the parent tabs are located at upper right.
The standard tabs in this template are the same as they are for the one-level tab layout.
Figure 9-8. Selecting the Issue Tracker parent tab shows its five standard tabs
Figure 9-9. Selecting the Admin parent tab shows the Users standard tab
You now have a navigational framework that clearly distinguishes the items needed to administer the application.
This design is extensible. As the application grows with time, additional features requiring administration could be
added to this navigational structure.
User Maintenance Data Entry
As part of the Help Desk design, you should be able to maintain the users from the application. To do this, you need
to implement some new database objects by locating, uploading, and running the script ch9_security_objects.sql .
Refer to Chapter 4 if you need step-by-step instructions. You should see 13 rows, all of which complete successfully.
Let's walk through briefly what this script does for you:
• Lines 1-16 : Create a function called hash_password that encodes any string passed to it.
• Lines 18-24 : Create the USERS table that will hold the user records.
• Lines 26-27 : Create the USER_SEQ sequence that will be used as the primary key for the USERS table.
• Lines 29-37 : Create a Before Insert trigger on the USERS table that automatically assigns the
next sequence as the primary key, converts the username to uppercase, and calls the
hash_password function to encrypt the user's password.
• Lines 39-50 : Create a Before Update trigger that converts the username to uppercase and
hashes the user's password if it has changed.
• Lines 52- 87: Create the authenticate_user function that validates whether the passed
username and password are valid compared to what exists in the USERS table.
• Lines 90- 103: Create six entries in the USERS table, all with the password apress .