Patrón de diseño Model-View-Controller

Vamos a crear un programa ejecutable implementamos el código fuente del patrón de diseño MVC creando las clases locales LCL_MODELO, LCL_VISTA y LCL_CONTROLADOR.
La clase modelo accede a la tabla de maestros de proveedores (LFA1) para obtener los datos.
Creamos un SELECT-OPTIONS para filtrar los datos por el campo LIFNR.
En la clase que representa la vista, utilizamos el módulo de funciones estándar REUSE_ALV_GRID_DISPLAY para pintar los datos.
En el evento START-OF-SELECTION probaremos todo el desarrollo.

1. La solución en código fuente:

   	DATA: gv_acreedor TYPE lifnr.
   	SELECT-OPTIONS so_lifnr FOR gv_acreedor.
   	*----------------------------------------------------------------------*
   	* CLASS lcl_modelo DEFINITION
   	*----------------------------------------------------------------------*
   	*
   	*----------------------------------------------------------------------*
   	CLASS lcl_modelo DEFINITION.
   	PUBLIC SECTION.
   	METHODS: set_modelo, " IMPORTING acreedores LIKE gt_range_acreedor,
   	get_modelo RETURNING VALUE(acreedores) TYPE bbp_lfa1_t.
   	PRIVATE SECTION.
   	DATA table_acreedores TYPE bbp_lfa1_t.
   	ENDCLASS. "lcl_modelo DEFINITION
   	*----------------------------------------------------------------------*
   	* CLASS lcl_modelo IMPLEMENTATION
   	*----------------------------------------------------------------------*
   	*
   	*----------------------------------------------------------------------*
   	CLASS lcl_modelo IMPLEMENTATION.
   	METHOD set_modelo.
   	SELECT * FROM lfa1
   	INTO TABLE table_acreedores
   	WHERE lifnr IN so_lifnr."acreedores.
   	ENDMETHOD. "set_modelo
   	METHOD get_modelo.
   	acreedores = table_acreedores.
   	ENDMETHOD. "get_modelo
   	ENDCLASS. "lcl_modelo IMPLEMENTATION
   	*----------------------------------------------------------------------*
   	* CLASS lcl_vista DEFINITION
   	*----------------------------------------------------------------------*
   	*
   	*----------------------------------------------------------------------*
   	CLASS lcl_vista DEFINITION.
   	PUBLIC SECTION.
   	METHODS pintar_acreedores IMPORTING acreedores TYPE bbp_lfa1_t.
   	ENDCLASS. "lcl_vista DEFINITION
   	*----------------------------------------------------------------------*
   	* CLASS lcl_vista IMPLEMENTATION
   	*----------------------------------------------------------------------*
   	*
   	*----------------------------------------------------------------------*
   	CLASS lcl_vista IMPLEMENTATION.
   	METHOD pintar_acreedores.
   	DATA lt_datos TYPE TABLE OF lfa1.
   	lt_datos = acreedores.
   	CALL FUNCTION 'REUSE_ALV_GRID_DISPLAY'
   	EXPORTING
   	* I_INTERFACE_CHECK = ' '
   	* I_BYPASSING_BUFFER = ' '
   	* I_BUFFER_ACTIVE = ' '
   	* I_CALLBACK_PROGRAM = ' '
   	* I_CALLBACK_PF_STATUS_SET = ' '
   	* I_CALLBACK_USER_COMMAND = ' '
   	* I_CALLBACK_TOP_OF_PAGE = ' '
   	* I_CALLBACK_HTML_TOP_OF_PAGE = ' '
   	* I_CALLBACK_HTML_END_OF_LIST = ' '
   	i_structure_name = 'LFA1'
   	* I_BACKGROUND_ID = ' '
   	* I_GRID_TITLE =
   	* I_GRID_SETTINGS =
   	* IS_LAYOUT =
   	* it_fieldcat = lt_fieldcat
   	* IT_EXCLUDING =
   	* IT_SPECIAL_GROUPS =
   	* IT_SORT =
   	* IT_FILTER =
   	* IS_SEL_HIDE =
   	* I_DEFAULT = 'X'
   	* I_SAVE = ' '
   	* IS_VARIANT =
   	* IT_EVENTS =
   	* IT_EVENT_EXIT =
   	* IS_PRINT =
   	* IS_REPREP_ID =
   	* I_SCREEN_START_COLUMN = 0
   	* I_SCREEN_START_LINE = 0
   	* I_SCREEN_END_COLUMN = 0
   	* I_SCREEN_END_LINE = 0
   	* I_HTML_HEIGHT_TOP = 0
   	* I_HTML_HEIGHT_END = 0
   	* IT_ALV_GRAPHICS =
   	* IT_HYPERLINK =
   	* IT_ADD_FIELDCAT =
   	* IT_EXCEPT_QINFO =
   	* IR_SALV_FULLSCREEN_ADAPTER =
   	* IMPORTING
   	* E_EXIT_CAUSED_BY_CALLER =
   	* ES_EXIT_CAUSED_BY_USER =
   	TABLES
   	t_outtab = lt_datos
   	EXCEPTIONS
   	program_error = 1
   	OTHERS = 2.
   	IF sy-subrc <> 0.
   	* MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
   	* WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
   	ENDIF.
   	ENDMETHOD. "pintar_acreedores
   	ENDCLASS. "lcl_vista IMPLEMENTATION
   	*----------------------------------------------------------------------*
   	* CLASS lcl_controlador DEFINITION
   	*----------------------------------------------------------------------*
   	*
   	*----------------------------------------------------------------------*
   	CLASS lcl_controlador DEFINITION.
   	PUBLIC SECTION.
   	METHODS: set_modelo IMPORTING modelo TYPE REF TO lcl_modelo,
   	get_modelo EXPORTING modelo TYPE REF TO lcl_modelo,
   	set_vista IMPORTING vista TYPE REF TO lcl_vista,
   	get_vista EXPORTING vista TYPE REF TO lcl_vista.
   	PRIVATE SECTION.
   	DATA: modelo TYPE REF TO lcl_modelo,
   	vista TYPE REF TO lcl_vista.
   	ENDCLASS. "lcl_controlador DEFINITION
   	*----------------------------------------------------------------------*
   	* CLASS lcl_controlador IMPLEMENTATION
   	*----------------------------------------------------------------------*
   	*
   	*----------------------------------------------------------------------*
   	CLASS lcl_controlador IMPLEMENTATION.
   	METHOD set_modelo.
   	me->modelo = modelo.
   	ENDMETHOD. "set_modelo
   	METHOD get_modelo.
   	modelo = me->modelo.
   	ENDMETHOD. "get_modelo
   	METHOD set_vista.
   	me->vista = vista.
   	me->vista->pintar_acreedores( acreedores = me->modelo->get_modelo( ) ).
   	ENDMETHOD. "set_vista
   	METHOD get_vista.
   	vista = me->vista.
   	ENDMETHOD. "get_vista
   	ENDCLASS. "lcl_controlador IMPLEMENTATION
   	START-OF-SELECTION.
   	DATA: gr_vista TYPE REF TO lcl_vista,
   	gr_modelo TYPE REF TO lcl_modelo,
   	gr_controlador TYPE REF TO lcl_controlador.
   	CREATE OBJECT: gr_vista,
   	gr_modelo,
   	gr_controlador.
   	gr_modelo->set_modelo( ).
   	gr_controlador->set_modelo( modelo = gr_modelo ).
   	gr_controlador->set_vista( vista = gr_vista ).

   view raw 02_12_05.abap hosted with ❤ by GitHub
2. La pantalla de selección de nuestro programa ejecutable:
3. Los resultados obtenidos: