Database Reference
In-Depth Information
CHAPTER 8
Programmatic Elements
This chapter covers the programmatic elements that can provide both simple and com-
plex features to the APEX framework. APEX provides simple declarative features with
wizards to guide you. Because of its integration with the database, APEX can also use
the full power of the PL/SQL engine inside the Oracle database. Now, with the imple-
mentation of APEX 4, even JavaScript interactivity has been made declarative and ex-
tendable in the framework.
Conditions
Throughout the building of the Help Desk application, there are times when you want to
take advantage of the conditional logic available with APEX components. Rather than
try to understand every type of condition (there are 60 in the list of condition types), you
should focus mainly on grasping the concept of a condition.
The condition feature provides a place where logic can turn on or off the particular
piece of APEX technology. Before action is taken to display or execute a particular
APEX component, the condition applied to that component is evaluated for a
TRUE
or
positive result.
The logic options available to develop a condition are very broad. The condition type
defines the particular mechanics used to evaluate the condition using parameters as ap-
propriate. Simple page-item comparisons are the easiest to explain. For example, a pro-
cess may only need to be run if a particular page item has a value. In the case of sending
an e-mail, an attempt to send a message should be made only if an e-mail address is giv-
en. From that simple start, conditions can become as complex as you need them to be. In
advanced cases, conditions can also include browser and web server options.
