Oracle JHeadstart Developer's Guide - Downloads - Oracle

13.5. Handling Forms PL/SQL Logic
13.5.1. Moving PL/SQL Logic to the Database
The JHeadstart Forms2ADF Generator allows you to “copy” the PL/SQL logic used in
the form to the JHeadstart Application Definition, so you can easily see the logic in the
editor, and determine what to do with it. Below we have listed common types of
PL/SQL logic, with some suggestions on how you might handle it. Note that this is a
high-level overview, not a detailed cookbook on how to handle each piece of PL/SQL
logic. Always make sure you fully understand the PL/SQL logic before you take a final
decision on how to re-implement it in the ADF/JHeadstart stack.
• Canvas and window management logic: this kind of logic can typically be
ignored, as it is specific to how Oracle Forms works.
• Navigation logic: logic to navigate to detail windows within the same form can
typically be ignored, since JHeadstart will generate buttons to navigate between
parent and detail groups. Navigation logic to call other forms, passing along
context parameter(s) used to query information in the called form can be
implemented using the JHeadstart Deep Linking functionality. See chapter 6
“Generating User Interface Widgets” section 6.14 “Hyperlink to Navigate
Context-Sensitive to Another Page (Deep Linking)” for more information.
• Logic to implement conditionally dependent items: with this we mean PL/SQL
logic that changes the user interface properties like required, enabled, or visible
for one or more “dependent” items based on the value(s) of one or more
“depends on” items. In other words, this kind of logic creates dynamic user
interfaces that change based on the values you enter. JHeadstart offers extensive
declarative support for conditionally dependent items. See chapter 6
“Generating User Interface Widgets”, section 6.12 “Conditionally Dependent
Items” for more information.
• Business rule logic: logic that causes error or messages or dialogs to be displayed
when the user enters invalid data, or logic that automatically updates other
values either directly in the form or by executing SQL DML statements (change
event rules). This kind of logic can be implemented in ADF Business
Components, as described in the Business Rules White Paper, or can be moved to
the database (in case it is not yet implemented there).
Reference: For information about enforcing business logic within the ADF BC
Business Service, see the whitepaper Business Rules in ADF BC:
otn.oracle.com/products/jdev/collateral/papers/10131/businessrulesinadfbc
technicalwp.pdf
When analyzing the PL/SQL logic in older forms, you might encounter a lot of PL/SQL
logic to implement business rules or computations that might well be executed inside the
Oracle Database. Using the “Move to database” icon in the JHeadstart Application
Definition Editor, which is enabled when you select a PL/SQL program unit or trigger in
the navigator tree, you can easily move such logic to the database.
If you want to call out to PL/SQL procedures or functions that you moved to the
database from a button in your ADF web page, you need to do the following:
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