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danrega
2023-05-08 16:52:32 +02:00
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@@ -3,42 +3,47 @@
* ABAP cheat sheet: Dynamic programming
*
* -------------------------- PURPOSE ----------------------------------
* - Example to demonstrate various syntactical options and concepts related
* - Example to demonstrate various syntax options and concepts related
* to dynamic programming.
* - Topics covered: Field symbols and data references (both as supporting
* elements for dynamic programming), dynamic ABAP syntax components,
* runtime type services (RTTS), i. e. runtime type identification (RTTI)
* and runtime type creation (RTTC)
* - To provide a "real" dynamic determination at runtime, the example
* includes local classes in the CCIMP include (local types tab in ADT)
* whose methods return character-like content to be used in the
* ABAP statements. The content is predefined in these classes but
* the content that is actually used in the end is random.
* - To provide a "real" dynamic determination at runtime for several code
* examples in this class, the example class includes local classes
* in the CCIMP include (local types tab in ADT) whose methods return
* character-like content to be used in the ABAP statements. The content
* is predefined in these classes but the content that is actually used
* in the end is random.
*
* ----------------------- GETTING STARTED -----------------------------
* - Open the class with the ABAP Development Tools (ADT).
* - Choose F9 to run the class.
* - Check the console output.
* - To understand the context and the ABAP syntax used, refer to the
* notes included in the class as comments or refer to the respective
* - To understand the context and the ABAP syntax used, refer to the
* notes included in the class as comments or refer to the respective
* topic in the ABAP Keyword Documentation.
* - Due to the amount of console output, the examples contain numbers
* (e.g. 1) ..., 2) ..., 3) ...) for the individual example sections.
* Also, the variable name is displayed in most cases. So to find
* the relevant output in the console easier and faster, just search
* for the number/variable name in the console (CTRL+F in the console)
* - Due to the amount of console output, the examples contain numbers
* (e.g. 1) ..., 2) ..., 3) ...) for the individual example sections.
* Also, the variable name is displayed in most cases. So to find
* the relevant output in the console easier and faster, just search
* for the number/variable name in the console (CTRL+F in the console)
* or use the debugger.
*
* ----------------------------- NOTE -----------------------------------
* Some code sections are commented out. The syntax is only available in
* newer ABAP releases. Comment them in if you are running a newer
* ABAP release, for example, in the SAP BTP environment.
*
* The code presented in this class is intended only to support the ABAP
* cheat sheets. It is not intended for direct use in a production system
* environment. The code examples in the ABAP cheat sheets are primarily
* intended to provide a better explanation and visualization of the
* syntax and semantics of ABAP statements, not to solve concrete
* programming tasks. For production application programs, you should
* always work out your own solution for each individual case. There is
* no guarantee for the correctness or completeness of the code.
* Furthermore, there is no legal responsibility or liability for any
* environment. The code examples in the ABAP cheat sheets are primarily
* intended to provide a better explanation and visualization of the
* syntax and semantics of ABAP statements, not to solve concrete
* programming tasks. For production application programs, you should
* always work out your own solution for each individual case. There is
* no guarantee for the correctness or completeness of the code.
* Furthermore, there is no legal responsibility or liability for any
* errors or their consequences that may occur when using the the example
* code.
*
@@ -155,12 +160,6 @@ CLASS zcl_demo_abap_dynamic_prog IMPLEMENTATION.
"Inline declaration is possible, too. The type is automatically derived.
ASSIGN num_a TO FIELD-SYMBOL(<fs_inl>).
"Assigning structure components to field symbols
"Component position
ASSIGN COMPONENT 2 OF STRUCTURE struc_a TO <fs_data_a>.
"Component name
ASSIGN COMPONENT 'CONNID' OF STRUCTURE struc_a TO <fs_data_a>.
output->display( `No output for this section. See the code.` ).
**********************************************************************
@@ -435,8 +434,13 @@ CLASS zcl_demo_abap_dynamic_prog IMPLEMENTATION.
DO.
"sy-index represents the position of a structure component
"NOTE: The following statement is replaced by the newer syntax that is
"commented out below. Therefore, it is recommended that you use this
"syntax in newer ABAP releases.
ASSIGN COMPONENT sy-index OF STRUCTURE <struct> TO <comp>.
"ASSIGN <struct>-(sy-index) to <comp>.
IF sy-subrc <> 0.
"If all components are processed, the loop is exited.
EXIT.
@@ -846,23 +850,133 @@ CLASS zcl_demo_abap_dynamic_prog IMPLEMENTATION.
**********************************************************************
output->next_section( `Dynamic ABAP Statements` ).
output->display( `20) Assignment of Dynamically ` &&
`Determined Data Objects to Field Symbols` ).
output->display( `20a) Dynamic Specifications in ASSIGN Statements (1) - Attributes of Classes/Interfaces` ).
"A dynamically determined data object is assigned to a field symbol.
"In this case, data objects that are declared in the public section of
"the local demo class are assigned to a field symbol.
"The following examples demonstrate a selection of various dynamic specifications
"that are possible with ASSIGN statements.
"Dynamic specification of attributes of classes/interfaces that are assigned to a field symbol.
DATA(dobj_name) = lcl_det_at_runtime=>get_dyn_dobj( ).
ASSIGN lcl_det_at_runtime=>(dobj_name) TO FIELD-SYMBOL(<fs_m>).
ASSIGN lcl_det_at_runtime=>(dobj_name) TO FIELD-SYMBOL(<fs_m1>).
output->display( |Data object name determined at runtime: { dobj_name } | ).
output->display( |The content of the data object is: { <fs_m> } | ).
output->display( |The content of the data object is: { <fs_m1> } | ).
dobj_name = lcl_det_at_runtime=>get_dyn_dobj( ).
"Completely dynamic assign
ASSIGN ('lcl_det_at_runtime')=>(dobj_name) TO FIELD-SYMBOL(<fs_m2>).
output->display( input = <fs_m2> name = `<fs_m2>` ).
ASSIGN ('zdemo_abap_objects_interface')=>('const_intf') TO FIELD-SYMBOL(<fs_m3>).
output->display( input = <fs_m3> name = `<fs_m3>` ).
"Class/interface reference variables pointing to an object that contains attributes
"and that are specified dynamically.
DATA iref TYPE REF TO zdemo_abap_objects_interface.
DATA(cl_ref) = NEW zcl_demo_abap_objects( ).
iref = cl_ref.
ASSIGN iref->('const_intf') TO FIELD-SYMBOL(<fs_m4>).
output->display( input = <fs_m4> name = `<fs_m4>` ).
ASSIGN cl_ref->('another_string') TO FIELD-SYMBOL(<fs_m5>).
output->display( input = <fs_m5> name = `<fs_m5>` ).
**********************************************************************
"Note: Comment in the following example in newer ABAP releases and in the SAP BTP environment.
* output->next_section( `20b) Dynamic Specifications in ASSIGN Statements (2) - Setting sy-subrc/ELSE UNASSIGN` ).
*
* "In dynamic assignments, the statement ASSIGN sets the return code sy-subrc.
* "If ELSE UNASSIGN is specified, no memory area is assigned to the field symbol. It has the state unassigned after the ASSIGN statement.
*
* DATA(attr) = VALUE string_table( ( `another_string` ) ( `public_string` ) ( `this_will_fail` ) ).
*
* LOOP AT attr INTO DATA(attribute).
*
* ASSIGN cl_ref->(attribute) TO FIELD-SYMBOL(<attr>) ELSE UNASSIGN.
* IF sy-subrc = 0.
* output->display( |Successful assignment for attribute "{ attribute }". sy-subrc = { sy-subrc }. | ).
* output->display( input = <attr> name = `<attr>` ).
* ELSE.
* output->display( |Assignment not successful for attribute "{ attribute }". sy-subrc = { sy-subrc }. | ).
* ENDIF.
*
* IF <attr> IS ASSIGNED.
* output->display( `The field symbol is assigned.` ).
* output->display( `--------------------` ).
* ELSE.
* output->display( `The field symbol is not assigned.` ).
* ENDIF.
*
* ENDLOOP.
**********************************************************************
"Note: The following code contains syntax that is only available in
"newer ABAP releases and in the SAP BTP environment. In these contexts,
"you can comment in the code.
output->next_section( `20c) Dynamic Specifications in ASSIGN Statements (3) - Structure Components` ).
"Dynamic specification of structure components that are assigned to a field symbol.
SELECT SINGLE * FROM zdemo_abap_carr INTO @DATA(wa).
"Reading into data reference variable
SELECT SINGLE * FROM zdemo_abap_carr INTO NEW @DATA(ref_m).
DATA(comp_name) = lcl_det_at_runtime=>get_dyn_field( ).
* ASSIGN wa-(comp_name) TO FIELD-SYMBOL(<fs_m6>).
*
* ASSIGN wa-('CARRNAME') TO FIELD-SYMBOL(<fs_m7>).
*
* IF sy-subrc = 0.
* DATA(subrc1) = sy-subrc.
* ENDIF.
*
* "No exception occurs in case of an unsuccessful assignment.
* ASSIGN wa-('CRRNM') TO FIELD-SYMBOL(<fs_m8>).
*
* IF sy-subrc <> 0.
* DATA(subrc2) = sy-subrc.
* ENDIF.
*
* "Numeric expressions are possible. Its value is interpreted as the position
* "of the component in the structure.
* ASSIGN wa-(4) TO FIELD-SYMBOL(<fs_m9>).
*
* "If the value is 0, the memory area of the entire structure is assigned to the field symbol.
* ASSIGN wa-(0) TO FIELD-SYMBOL(<fs_m10>).
"The above statements replace the following syntax syntax
ASSIGN COMPONENT 'CARRID' OF STRUCTURE wa TO FIELD-SYMBOL(<fs_m11>).
ASSIGN COMPONENT 5 OF STRUCTURE wa TO FIELD-SYMBOL(<fs_m12>).
"Dynamically specifying components of structures that are referenced by
"a data reference variable
ASSIGN ref_m->('CARRNAME') TO FIELD-SYMBOL(<fs_m13>).
* output->display( input = <fs_m6> name = `<fs_m6>` ).
* output->display( input = <fs_m7> name = `<fs_m7>` ).
* output->display( input = subrc1 name = `subrc1` ).
* output->display( input = subrc2 name = `subrc2` ).
* output->display( input = <fs_m9> name = `<fs_m9>` ).
* output->display( input = <fs_m10> name = `<fs_m10>` ).
output->display( input = <fs_m11> name = `<fs_m11>` ).
output->display( input = <fs_m12> name = `<fs_m12>` ).
output->display( input = <fs_m13> name = `<fs_m13>` ).
**********************************************************************
output->next_section( `21) Dynamically Specifying Components` ).
output->next_section( `Dynamically Specifying Components/Clauses in Statements for Processing Internal Tables with ...` ).
output->display( `21) SORT` ).
"A field is determined at runtime on whose basis a sorting is done on an
"internal table.
@@ -881,10 +995,172 @@ CLASS zcl_demo_abap_dynamic_prog IMPLEMENTATION.
|by which the sorting was done: { field_name } | ).
output->display( input = carr_itab name = `carr_itab` ).
**********************************************************************
output->next_section( `22) READ TABLE` ).
"Dynamic key specification in READ TABLE statements
TYPES: BEGIN OF s,
comp TYPE string,
value TYPE string,
END OF s.
TYPES comps_type TYPE TABLE OF s WITH EMPTY KEY.
"Providing components and values for READ TABLE statement
DATA(comps) = VALUE comps_type( ( comp = `CARRID` value = `LH` )
( comp = `CONNID` value = `0555` )
( comp = `SEATSOCC` value = `115` )
( comp = `CARRID` value = `XY` ) ). "not found
SELECT *
FROM zdemo_abap_fli
INTO TABLE @DATA(itab_read_tab_dyn).
LOOP AT comps INTO DATA(wa_comps).
READ TABLE itab_read_tab_dyn
INTO DATA(read_line)
WITH KEY (wa_comps-comp) = wa_comps-value.
IF sy-subrc = 0.
output->display( input = wa_comps-comp name = `wa_comps-comp` ).
output->display( input = wa_comps-value name = `wa_comps-value` ).
output->display( input = read_line name = `read_line` ).
CLEAR read_line.
ELSE.
output->display( input = wa_comps-comp name = `wa_comps-comp` ).
output->display( input = wa_comps-value name = `wa_comps-value` ).
output->display( `Line not found.` ).
ENDIF.
ENDLOOP.
**********************************************************************
output->next_section( `23) MODIFY` ).
"Dynamic WHERE condition in MODIFY statements
"Note:
"- The addition WHERE can only be specified together with the addition TRANSPORTING.
"- Invalid logical expressions raise an exception from the class CX_SY_ITAB_DYN_LOOP.
TYPES:
BEGIN OF line,
col1 TYPE c LENGTH 1,
col2 TYPE i,
END OF line.
DATA itab_mod_tab_dyn TYPE SORTED TABLE OF line
WITH UNIQUE KEY col1.
itab_mod_tab_dyn = VALUE #( ( col1 = 'A' col2 = 1 )
( col1 = 'B' col2 = 10 )
( col1 = 'C' col2 = 100 ) ).
output->display( `Internal table content before modifications:` ).
output->display( input = itab_mod_tab_dyn name = `itab_mod_tab_dyn` ).
"Providing conditions for MODIFY statement
DATA(conditions) = VALUE string_table( ( `col2 < 5` )
( `col2 = 10` )
( `colxyz > 50` ) ). "to fail
LOOP AT itab_mod_tab_dyn INTO DATA(wa_mod_dyn).
TRY.
DATA(condition) = conditions[ sy-tabix ].
MODIFY itab_mod_tab_dyn
FROM VALUE line( col2 = wa_mod_dyn-col2 * 2 )
TRANSPORTING col2
WHERE (condition).
CATCH cx_sy_itab_dyn_loop.
output->display( |Invalid WHERE condition "{ condition }".| ).
ENDTRY.
ENDLOOP.
output->display( `Internal table content after modifications:` ).
output->display( input = itab_mod_tab_dyn name = `itab_mod_tab_dyn` ).
**********************************************************************
output->next_section( `24) DELETE` ).
"Dynamic WHERE condition in DELETE statements
DATA itab_del_tab_dyn TYPE TABLE OF i WITH EMPTY KEY
WITH NON-UNIQUE SORTED KEY skey COMPONENTS table_line.
itab_del_tab_dyn = VALUE #( ( 100 )
( 200 )
( 300 )
( 400 )
( 500 )
( 600 ) ).
output->display( `Internal table content before modifications:` ).
output->display( input = itab_del_tab_dyn name = `itab_del_tab_dyn` ).
DO 3 TIMES.
TRY.
CASE sy-index.
WHEN 1.
condition = `table_line <= 200`.
WHEN 2.
condition = `table_line >= 500`.
WHEN 3.
condition = `col1 = 600`.
ENDCASE.
DELETE itab_del_tab_dyn
USING KEY skey
WHERE (condition).
output->display( |Condition: { condition }| ).
output->display( input = itab_del_tab_dyn name = `itab_del_tab_dyn` ).
CATCH cx_sy_itab_dyn_loop.
output->display( |Invalid WHERE condition "{ condition }".| ).
ENDTRY.
ENDDO.
**********************************************************************
output->next_section( `25) LOOP` ).
"Dynamic specification of the key in LOOP statements
"In the example, the loop can be executed with the entries 'skey' and 'primary_key'.
"This is not case sensitive. Any other entries produce a runtime error.
DATA(keys) = VALUE string_table( ( `primary_key` ) ( `SKEY` ) ).
DATA itab_loop TYPE TABLE OF i
WITH NON-UNIQUE KEY primary_key COMPONENTS table_line
WITH NON-UNIQUE SORTED KEY skey COMPONENTS table_line.
itab_loop = VALUE #( ( 3 ) ( 2 ) ( 1 ) ).
DATA itab_dyn_key LIKE itab_loop.
LOOP AT keys INTO DATA(k).
LOOP AT itab_loop INTO DATA(wa_lo) USING KEY (k).
APPEND wa_lo TO itab_dyn_key.
ENDLOOP.
output->display( |Loop over internal table using key "{ k }".| ).
output->display( input = itab_dyn_key name = `itab_dyn_key` ).
CLEAR itab_dyn_key.
ENDLOOP.
**********************************************************************
output->next_section( `Dynamically Specifying Clauses in ABAP SQL SELECT Statements` ).
output->display( `22) SELECT List` ).
output->display( `26) SELECT List` ).
"In the example, the SELECT list that is used in a SELECT statement is
"determined at runtime.
@@ -904,7 +1180,7 @@ CLASS zcl_demo_abap_dynamic_prog IMPLEMENTATION.
**********************************************************************
output->next_section( `23) FROM Clause` ).
output->next_section( `27) FROM Clause` ).
"In the example, the FROM clause that is used in a SELECT statement is
"determined at runtime. Here, the number of entries of a database table
@@ -921,7 +1197,7 @@ CLASS zcl_demo_abap_dynamic_prog IMPLEMENTATION.
**********************************************************************
output->next_section( `24) WHERE Clause` ).
output->next_section( `28) WHERE Clause` ).
"In the example, the WHERE clause that is used in a SELECT statement is
"determined at runtime. Here, the WHERE clause is based on a string
@@ -942,7 +1218,7 @@ CLASS zcl_demo_abap_dynamic_prog IMPLEMENTATION.
**********************************************************************
output->next_section( `25) Excursion: Multiple Dynamically Specified ` &&
output->next_section( `29) Excursion: Multiple Dynamically Specified ` &&
`Clauses in an ABAP SQL SELECT Statement` ).
"In this example, multiple clauses in a SELECT statement are
@@ -979,7 +1255,7 @@ CLASS zcl_demo_abap_dynamic_prog IMPLEMENTATION.
**********************************************************************
output->next_section( `26) Dynamic Invoke` ).
output->next_section( `30) Dynamic Invoke` ).
"In the example, both class and method are determined at runtime for
"the method call. The suitable parameter table is filled in the
@@ -1020,7 +1296,7 @@ CLASS zcl_demo_abap_dynamic_prog IMPLEMENTATION.
**********************************************************************
output->next_section( `27) RTTI: Determining Data and Object Types at Runtime` ).
output->next_section( `31) RTTI: Determining Data and Object Types at Runtime` ).
"The example demonstrates RTTI as follows:
"- The method call takes care of providing the name of a type. It is implemented
@@ -1159,7 +1435,7 @@ CLASS zcl_demo_abap_dynamic_prog IMPLEMENTATION.
**********************************************************************
output->next_section( `28) RTTC: Dynamically Creating Elementary Data Objects` ).
output->next_section( `32) RTTC: Dynamically Creating Elementary Data Objects` ).
"The example demonstrates RTTC as follows:
"- The method call takes care of providing the name of a built-in data type and more
@@ -1198,7 +1474,7 @@ CLASS zcl_demo_abap_dynamic_prog IMPLEMENTATION.
**********************************************************************
output->next_section( `29) RTTC: Dynamically Creating Structured Data Object (1)` ).
output->next_section( `33) RTTC: Dynamically Creating Structured Data Object (1)` ).
"The example demonstrates RTTC as follows:
"- The method call takes care of providing the name of a database table name.
@@ -1236,7 +1512,7 @@ CLASS zcl_demo_abap_dynamic_prog IMPLEMENTATION.
**********************************************************************
output->next_section( `30) RTTC: Dynamically Creating Structured Data Object (2)` ).
output->next_section( `34) RTTC: Dynamically Creating Structured Data Object (2)` ).
"This example includes the dynamic definition of a structure with three components
"using the GET method of the CL_ABAP_STRUCTDESCR class.
@@ -1292,7 +1568,7 @@ CLASS zcl_demo_abap_dynamic_prog IMPLEMENTATION.
**********************************************************************
output->next_section( `31) RTTC: Dynamically Creating Internal Table (1)` ).
output->next_section( `35) RTTC: Dynamically Creating Internal Table (1)` ).
"The example demonstrates RTTC as follows:
"- The method call takes care of providing the name of a database table name.
@@ -1319,7 +1595,7 @@ CLASS zcl_demo_abap_dynamic_prog IMPLEMENTATION.
**********************************************************************
output->next_section( `32) RTTC: Dynamically Creating Internal Table (2)` ).
output->next_section( `36) RTTC: Dynamically Creating Internal Table (2)` ).
"In the example an internal table type is created based on a DDIC type.
"See the comments in the code.
@@ -1376,4 +1652,4 @@ CLASS zcl_demo_abap_dynamic_prog IMPLEMENTATION.
output->display( input = ref_tab->* name = `ref_tab->*` ).
ENDMETHOD.
ENDCLASS.
ENDCLASS.