ABAP_to_the_Future

8
Business Object Processing Framework (BOPF)
ASSIGN lrt_monster_items->* TO <lt_monster_items>.
et_monster_items = <lt_monster_items>.
ENDMETHOD.
"Retrieve Monster Record
Listing 8.2 Model Class Retrieval Method
You will note that due to the fully generic nature of the BOPF classes and methods,
you have to devote a lot of effort to converting generic data objects into
actual structures and tables you can work with directly.
You will also see that Listing 8.2 includes a call to an instance of a helper class.
Section 8.3.2 explains how best to wrap the generic BOPF classes and methods in
a more developer-friendly API, but for now anything monster-specific goes in the
monster model class (or its persistency-layer friend) and anything fully generic
goes into a reusable BOPF helper class; this helper class is named MO_BOPF_PL_
HELPER in the example code. This all means that how the data is retrieved is several
levels down from the monster model class. You now have a nice level of
abstraction, because it’s not the model’s concern how data is obtained; this helps
with unit testing.
Next, Listing 8.3 delves into the method that turns the monster number into a
key. You’re going to be using the quer y you defined earlier (Figure 8.9), which
enables you to do a search on the databasefor attributes other than the GUID key.
METHOD get_bopf_key_4_monster_number.
*---------------------------------------------------------------*
* IMPORTING id_monster_number TYPE ZDE_MONSTER_NUMBER
* RETURN rd_bopf_key TYPE /BOBF/CONF_KEY
*---------------------------------------------------------------*
* Local Variables
DATA : lt_parameters TYPE /bobf/t_frw_query_selparam,
lt_monster_keys TYPE /bobf/t_frw_key.
FIELD-SYMBOLS : <ls_parameter> LIKE LINE OF lt_parameters,
<ls_monster_keys> LIKE LINE OF lt_monster_keys.
* This builds the dynamic WHERE clause for the database read
APPEND INITIAL LINE TO lt_parameters ASSIGNING <ls_parameter>.
<ls_parameter>-attribute_name =
zif_monster_c=>sc_query_attribute-monster_header- select_monster_by_
attribute-monster_number.
<ls_parameter>-sign = 'I'.
<ls_parameter>-option = 'EQ'.
298