Handle tab backward from required item in Oracle Forms 12C - oracle12c

Question

I have migrated Oracle Forms 10g to 12c and unusual issues occurring in 12c. Here is one of the issues feedback from users.
I have a form that have certain required fields. When users leave the item blank, error message "Field are required" display on form status bar. It is usual that users cannot go to next field until put something in the required item.
In 10g, users could tab backward leaving required field blank without error, but not in 12c anymore.
I came out a method which something like that (cannot say it is solution at all):
Step1. Initial Required to "Yes" in the item property platelet.
Step2. Create key-prev-item to the required items and put the following code:
If get_item_property(:system.cursor_name, required) = ‘true’ then
Set_item_property(:system.cursor_name, required, property_false);
End if;
Step3. Create key-next-item to the required items and reset the required property to true.
It looks silly and unreliable since the more codes you create, the more bugs will coming out.
Is there any build-in function in Oracle Form 12c handle such case?
Many many thanks

Answer 1

I think it is better to use the DEFER_REQUIRED_ENFORCEMENT at that moment.
We do this like that, we set it to true if we navigate out of the item and false after the navigation.
Usage Notes from oracle formsbuilder help to explain difference between option Yes and 4.5:
This property applies only when item-level validation is in effect. By default, when an item has Required set to true, Oracle Forms will not allow navigation out of the item until a valid value is entered. This behavior will be in effect if you set Defer Required Enforcement to No. (An exception is made when the item instance does not allow end-user update; in this unusual case, a Defer Required Enforcement setting of No is ignored and item-level validation does not take place.)
If you set Defer Required Enforcement to Yes (PROPERTY_TRUE for runtime) or to 4.5 (PROPERTY_4_5 for runtime), you allow the end user to move freely among the items in the record, even if they are null, postponing enforcement of the Required attribute until validation occurs at the record level.
When Defer Required Enforcement is set to Yes, null-valued Required items are not validated when navigated out of. That is, the WHEN-VALIDATE-ITEM trigger (if any) does not fire, and the item's Item Is Valid property is unchanged. If the item value is still null when record-level validation occurs later, Oracle Forms will issue an error.
When Defer Required Enforcement is set to 4.5, null-valued Required items are not validated when navigated out of, and the item's Item Is Valid property is unchanged. However, the WHEN-VALIDATE-ITEM trigger (if any) does fire. If it fails (raises Form_Trigger_Failure), the item is considered to have failed validation and Oracle Forms will issue an error. If the trigger ends normally, processing continues normally. If the item value is still null when record-level validation occurs later, Oracle Forms will issue an error at that time.
Setting a value of 4.5 for Defer Required Enforcement allows you to code logic in a WHEN-VALIDATE-ITEM trigger that will be executed immediately whenever the end-user changes the item's value (even to null) and then navigates out. Such logic might, for example, update the values of other items. (The name "4.5" for this setting reflects the fact that in Release 4.5, and subsequent releases running in 4.5 mode, the WHEN-VALIDATE-ITEM trigger always fired during item-level validation.)
Migration note: If your Forms application used "4.5" as the Runtime Compatibility Mode property setting, the Oracle Forms Migration Assistant will automatically set the Defer Required Enforcement property to "4.5" because the Runtime Compatibility Mode property is obsolete in Oracle Forms.