Handling higher level Boolean values in SAP system

As per the general standards and coding practice, you should use abap_bool for handling Boolean values or truth values in SAP systems. When any object is declared as abap_bool type, it can hold values only from the set (abap_true, abap_false, and abap_undefined). However, in older systems, you might not be able to use abap_bool as it is not available. For example, in Web Dynpro ABAP, abap_bool is not available.

You need to use WDY_BOOLEAN as an alternative in this case. WDY_BOOLEAN only allows true Boolean values, meaning it allows only true and false as permissible values but not undefined.

Using abap_bool in ABAP

Here's how you can declare and use abap_bool variables in standard ABAP ?

DATA: lv_flag TYPE abap_bool.

" Setting values
lv_flag = abap_true.
lv_flag = abap_false.
lv_flag = abap_undefined.

" Using in conditional statements
IF lv_flag = abap_true.
  WRITE: 'Flag is true'.
ELSEIF lv_flag = abap_false.
  WRITE: 'Flag is false'.
ELSE.
  WRITE: 'Flag is undefined'.
ENDIF.

Using WDY_BOOLEAN in Web Dynpro ABAP

When working with Web Dynpro ABAP applications, use WDY_BOOLEAN for Boolean operations ?

DATA: lv_visible TYPE wdy_boolean.

" Setting values (only true/false allowed)
lv_visible = abap_true.
lv_visible = abap_false.

" Using with UI elements
lo_ui_element->set_visible( lv_visible ).

" Conditional logic
IF lv_visible = abap_true.
  " Element is visible
ELSE.
  " Element is hidden
ENDIF.

Key Differences

The main differences between abap_bool and WDY_BOOLEAN are ?

• Value Range: abap_bool supports three states (true, false, undefined), while WDY_BOOLEAN supports only two (true, false)
• Availability: abap_bool is available in standard ABAP, while WDY_BOOLEAN is specific to Web Dynpro contexts
• Usage Context: Use abap_bool for general ABAP development and WDY_BOOLEAN for Web Dynpro applications

Conclusion

Choose abap_bool for standard ABAP development when you need three-state logic, and use WDY_BOOLEAN in Web Dynpro ABAP when only binary true/false values are required.