BAdI: Customer-Defined Functions in the
Formula Builder
Use
You can integrate
your own functions in the Formula Builder transformation library. This allows
you to make special functions that are not contained in the transformation
library available for frequent use.
Business Add-In RSAR_CONNECTOR is available for this purpose. In this
BAdI, you define which class or method your function was implemented in and
under which entry the function will be offered in the Formula Builder. The
actual implementation of the function takes place in the specified class or
method. For more information about using Business Add-Ins (BAdIs), see
Business
Add-Ins.
Procedure
Implementing the BAdI
...
1.
You can find
information about how to implement a BAdI under
Implementation of a
Business Add-In. The specific things to look out for when implementing
BAdI RSAR_CONNECTOR are described below.
2. Call transaction SE19. Enter RSAR_CONNECTOR as the name of the add-in that you want to create the implementation for.
3.
By double-clicking
the method (GET), the class builder appears. Here you can enter your coding to
implement the enhancement. You can define which entry your function will be
displayed with and which category it will be displayed under in the Formula
Editor. You also define the class or method that the function was implemented
in. More information: Structure of
Implementing a Function and Implementing a
Category.
The following sample coding defines that the function C_TIMESTAMP_TO_DATE is displayed in the Formula Editor under the category Custom: Date/Time Functions.
METHOD IF_EX_RSAR_CONNECTOR~GET.
Data: l_function type SFBEOPRND.
CASE i_key.
WHEN space.
l_function-descriptn = 'Custom: Date/Time Functions'.
**** Description of the category ***
l_function-tech_name = 'C_TIME'.
*** Name of the category in uppercase ***
APPEND l_function TO c_operands.
*** Coding for the function ***
WHEN 'C_TIME'.
CLEAR l_function.
l_function-tech_name = 'C_TIMESTAMP_TO_DATE'.
l_function-descriptn = 'Convert Timestamp (Len 15) to Date'.
l_function-class = 'ZCL_IM_CUSTOM_FUNCTIONS'.
l_function-method = 'C_TIMESTAMP_TO_DATE'.
APPEND l_function TO c_operands.
ENDCASE.
ENDMETHOD.
A function does not have a type, meaning that the TYPE field in structure SFBEOPRND cannot be filled.
4. Save and activate your implementation.
Naming Conventions
The technical name of a user-defined function:
● cannot be empty
● must be unique
● must begin with ‘C_’
● can only contain alphanumeric characters: 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_' (small letters, blank spaces and special characters are not allowed)
● can have a maximum of 61 characters
Implementing the Methods
The ABAP methods specified in the function description under class and method (in the BADI implementation) are called later in maintenance and formula evaluation. You define which processing is performed by the function. The customer-defined functions therefore also have to implemented as methods for BAdI implementation in an additional class. These methods must have the following properties:
● They are declared as static and public.
● They can only have importing, exporting, and returning parameters. Changing parameters are not permitted.
● They can only have one exporting or returning parameter.
● Exporting parameters cannot have a generic type.
In the methods, you can use ABAP code to implement the function.
The system does not check whether the class or method specified in BAdI implementation actually exists. If a class or method does not exist, a runtime error occurs when the function is used in the formula builder.
Coding example for a simple customer-defined function in which a timestamp is entered in function RS_TBBW_CONVERT_TIMESTAMP and converted into a date:
Method C_TIMESTAMP_TO_DATE.
**** Enter code here *******
CALL FUNCTION ‘RS_TBBW_CONVERT_TIMESTAMP’
EXPORTING
i_timestamp = i_timestamp
IMPORTING
E_data = e_dat.
************************
ENDMETHOD.
Result
The functions you have defined are available in the transformation library in the Customer-Defined Functions selection.