Oracle Forms : Validation Triggers

Validation & Navigational Triggers

http://ebiztechnics.blogspot.com

Objectives

• What is Validation Unit?• Form Builder Validation Properties• Using triggers to implement Validation

• Navigation in Forms• Navigation Properties• Navigational Triggers• Built-ins used for Navigation


Validation in Form Builder

• Form Builder provides the Validation at 4 Levels:

Form Level

Block Level

Record Level Item Level


Validation

• Validation occurs when:– Enter key is pressed or ENTER Built-in execute.– Operator or trigger leaves the validation unit (includes a Commit)


Validation Property

Form ModuleProperties -> Database->Validation Unit


Validate from list

• Text item Property• Used to validate from LOV• If the input value does not exist in LOV the List of values window

appears to choose.

• Note: Do not use this property for large number of values.


Validation Triggers

• Item Level– When-Validate-Item

• Block Level– When-Validate-Record

IF :emp.ename is null or :emp.hiredate is null THEN message(‘Employee name or

Joining Date can not be blank’); RAISE form_trigger_failure;END IF;


Validating User Input

• Salary Details Form.

7987Emp No When-Validate-Item

SELECT ……….FROM empWHERE empno=:empsal.empno;

Trigger Failure


Validation Status

• NEW– When a record is created– Also for Copy Value from Item or Initial Value

• CHANGED– When changed by user or trigger– When any item in new record is changed

• VALID– When validation has been successful– After records are fetched from database– After a successful post or commit– Duplicated record inherits status of source


Built-ins for Validation

• CLEAR_BLOCK, CLEAR_ FORM, EXIT_FORM• ENTER• SET_FORM_PROPERTY

– (..., VALIDATION)– (..., VALIDATION_UNIT)

• ITEM_IS_VALID item property• VALIDATE (VALIDATION_ UNIT)

SET_FORM_PROPERTY(‘FORM_MOD’,VALIDATION_UNIT,);ITEM_SCOPE

RECORD_SCOPE / BLOCK_SCOPE / FORM_SCOPE


Navigation in forms

• What is Navigational Unit?• Navigation in

– Form– Block– Record– Item

• Entering and Leaving Objects• What happens if navigation fails?


Navigation Properties

• Form module– Mouse navigation limit– First navigation data block

• Block– Navigation style– Previous navigation data block– Next navigation data block

• Item– Enabled– Keyboard navigable– Mouse navigate – Previous navigation item– Next navigation item


Navigation in Blocks

Exit item

Exit record

Exit block

Enter block

Enter record

Enter item


Internal Navigation

Exit item

Exit record

Enter record

Enter item


Navigational Triggers

When-New-“object”-Instance

Fire after navigation

Does fire when validation unit is higher than the trigger object

Allow restricted and unrestricted built-ins

Are not affected by failure

Pre- and Post-

Fire during navigation

Does not fire if validation unit is higher than trigger object

Allow unrestricted built-ins

Handle failure by returning to initial object


Pre- and Post- Triggers

• Pre/Post-Form • Pre/Post-Block • Pre/Post-Record• Pre/Post-Text-Item


Example Pre-Block Trigger

IF GET_APPLICATION_PROPERTY(username)=‘SCOTT’ THEN SET_BLOCK_PROPERTY(‘EMP’,UPDATE_ALLOWED, Property_False);

END IF;


When-New-”object” Instance

• When-New-Form-Instance• When-New-Block-Instance• When-New-Record-Instance• When-New-Item-Instance


Examples

SET_FORM_PROPERTY(‘EMPL’, VALIDATION_UNIT, RECORD_SCOPE);

SET_BLOCK_PROPERTY(‘EMP’, QUERY_ALLOWED, PROPERTY_FALSE);

READ_IMAGE_FILE(‘E_’||:emp.empno||’.bmp’,’BMP’, ’emp.emp_image);

SET_ITEM_PROPERTY(:SYSTEM.cursor_item, visual_attribute, ‘vared’);


Navigational Trap

Pre-Text-Item

Pre-Text-Item

Post-Text-Item


Summary

• Validation Unit• Triggers and Built-ins for Validation.

– When-Validate-Item and When-Validate-Record• Validation Properties

• Navigation in Forms• Internal and External Navigation• Navigational Triggers

– Pre- , Post- and When-New-”Object”-Instance Triggers


Oracle Forms : Validation Triggers

Software

Transcript of Oracle Forms : Validation Triggers