ABAP_to_the_Future

8
Business Object Processing Framework (BOPF)
DATA ls_parameters TYPE zsa_howl_at_the_moon.
DATA lr_s_parameters TYPE REF TO data.
* If not even one howl is possible, no point in going on
ls_parameters-no_of_howls = 1.
GET REFERENCE OF ls_parameters INTO lr_s_parameters.
* Check to see if the HOWL action can be invoked:
DATA lo_message TYPE REF TO /bobf/if_frw_message.
DATA lt_failed_key TYPE /bobf/t_frw_key.
DATA lt_failed_act_key TYPE /bobf/t_frw_key.
CALL METHOD mo_service_manager->check_action
EXPORTING
iv_act_key = zif_monster_c=>sc_action-root-howl_at_the_moon
it_key = lt_key
is_parameters = lr_s_parameters
IMPORTING
eo_message
= lo_message
et_failed_key = lt_failed_key
et_failed_action_key = lt_failed_act_key.
IF lt_failed_act_key[] IS NOT INITIAL.
"The action would fail – do not add the button
ENDIF.
CATCH /bobf/cx_frw INTO lx_frw.
"The action would fail really badly, do not add the button
ENDTRY.
Listing 8.12 Invoking an Action Validation Manually
Note
In Section 8.2.8, you will look at how user commands are processed in BOPF using
actions and how an action validation is run automatically by the framework just before
a user command (action) is executed.
8.2.7 Checking Data Integrity Using Validations
Before you save your data to the database, you want to be sure it’s in a consistent
state. In fact, you want to check this not only at the time of saving but often many
times throughout the transaction. In BOPF, this is handled via validations. Validations
are called automatically during sa ve, but can also be called on demand.
Often, in DYNPRO programs the equivalent code to perform a validation is called
after every user entry (i.e., during PAI) , but that could seem excessive; in any
318