Groovy Expression Usage in ADF, JDeveloper

Different points where Goovy code can be dropped:

1. Values for View and Entity objects attributes.

2. Validation rules on Entity object attributes.

3. Expressions for error messages.

4. Values for view object bind variables.

5. View object transient attribute validations.

Some of the properties of groovy scripting language

- Groovy is a scripting language having java like syntax
- Groovy is executed at run time
-  Can be used in Entity and View objects in attribute validators(Entity Objects),attribute default values( Entity and View),bind variable default values ( View) place holder for error messages (EO validation rules)
- Define script expression validator or Compare validator 
- Error message tokens can be defined for handling validation failures 
- Conditional execution of validatiors are possible 
- Default value of bind variable in view object can be defined using groovy expression 
- Default value of view criteria 
- Default value and optional re-calculation condition for EO
- Value of transient for EO and VO 

Referencing Buisiness components objects in Groovy expression

Top level object is "adf" . Accessible ADF objects throgh groovy are 

- adf.context - Reference to ADFContext 

- adf.object - Equivalent to this operator in java.

- Entity Objects attributes - Reference methods and attributes of EntityImpl class.

- Entity Objects script validator rules - Attributes and method of ViewImpl class.

- View Object attributes 

- Bind Variable in view Object 

- Bind variable in view accessors 

- Transient attributes 

- adf.error 

- adf.userSession 

- adf.currentDate 

- adf.currentDateTime 

- Referencing custom buisiness components methods and attributes 

eg. Sal*12 - annualsalary .

PromotionDate>HireDate 

Method of entity class in validation rule.For validators use source keyword

eg. source.getDefaultSalaryForGrade()

- newValue - Attribute value being set 

-oldValue - current value of attribute being set 

if(Job=’SALESMAN’)

{

 return newValue<source.getMaxSalaryForGrade(Job)

}

Manipulating business component attribute values in a groovy expression

RowSet Objects

-          rowSetAttr.sum(GroovyExpr)

-          rowSetAttr.count(GroovyExpr)

-          rowSetAttr.avg(GroovyExpr)

-          rowSetAttr.min(GroovyExpr)

-          rowSetAttr.max(GroovyExpr)

EmployeesInDept.sum(“Sal+adf.object.getBenefitsValue(Job)”)