英文原文：SAP-samples · 上游版本 d43eb13c4c7c · 原始 Markdown

Selection Screens and Classic Lists

Selection Screens and Classic Lists

Introduction

[!NOTE] The content of this cheat sheet and the executable examples are only relevant to classic ABAP.

Selection screens and classic lists are among the classic ABAP user interfaces. They are integrated into the ABAP language itself, which means that special ABAP statements are available to create and handle them.

This cheat sheet provides a high-level overview of selection screens and classic lists, focusing on a selection of related statements, supported by executable examples to explore the syntax in action. It includes an excursion into the SAP List Viewer (ALV).

For more detailed information and syntax options, see the topics Selection Screens and Classic Lists in the ABAP Keyword Documentation.

[!NOTE]

Although they are considered outdated for application programs, you will still find classic ABAP UIs frequently in classic ABAP.

Classic ABAP UIs cannot be created in ABAP Cloud.

This cheat sheet ...

is not intended to encourage you to start creating classic ABAP UIs for programming new applications.

does not cover all facets, techniques, and syntax options (there's a rich variety of keywords and additions) in great detail.

is intended to cover a selection of related syntax that you may encounter in older ABAP code. If you need more information, always consult the ABAP Keyword Documentation.

Links to the ABAP Keyword Documentation in this cheat sheet refer to the documentation for Standard ABAP (latest version).

Subject/Statement	Notes	Code Snippet
Adding blank lines `SELECTION-SCREEN SKIP`	Creates a specified number of lines If a number is not specified, one blank line is created by default.	PARAMETERS param1 TYPE c LENGTH 20. SELECTION-SCREEN SKIP. PARAMETERS param2 TYPE c LENGTH 20. SELECTION-SCREEN SKIP 3. PARAMETERS param3 TYPE c LENGTH 20. START-OF-SELECTION. WRITE / `Inserted values:`. SKIP. WRITE / \|param1: "{ param1 }"\|. WRITE / \|param2: "{ param2 }"\|. WRITE / \|param3: "{ param3 }"\|.
Creating horizontal lines `SELECTION-SCREEN ULINE`	Formatting options are available: Position from where to start the line and length specification Either the position (1-83) is specified directly as number or with the additions `POS_LOW` (position of first input field) and `POS_HIGH` (position of second inut field). `/` creates the line a new line; cannot be specified if multiple elements are specified in a line If no formatting options are specified, a line is created that goes accross the whole screen below the lines that are already filled. The addition `MODIF ID` is supported. Find more details here.	PROGRAM. PARAMETERS param1 TYPE c LENGTH 20. SELECTION-SCREEN ULINE. PARAMETERS param2 TYPE c LENGTH 20. "/ means the line is created in a new line "/ is followed by the position and the length in parentheses SELECTION-SCREEN ULINE /5(10). PARAMETERS param3 TYPE c LENGTH 20. "SELECTION-SCREEN ULINE 5(10). PARAMETERS param4 TYPE c LENGTH 20. SELECTION-SCREEN ULINE /pos_low(15). PARAMETERS param5 TYPE c LENGTH 20. SELECTION-SCREEN ULINE /pos_high(15). "/ can be ommitted if the elements are in the same line SELECTION-SCREEN BEGIN OF LINE. PARAMETERS param6 TYPE c LENGTH 1. SELECTION-SCREEN ULINE 4(5). PARAMETERS param7 TYPE c LENGTH 1. SELECTION-SCREEN ULINE pos_low(20). PARAMETERS param8 TYPE c LENGTH 1. SELECTION-SCREEN ULINE pos_high(40). SELECTION-SCREEN END OF LINE. START-OF-SELECTION. WRITE / `Inserted values:`. SKIP. WRITE / \|param1: "{ param1 }"\|. WRITE / \|param2: "{ param2 }"\|. WRITE / \|param3: "{ param3 }"\|. WRITE / \|param4: "{ param4 }"\|. WRITE / \|param5: "{ param5 }"\|. WRITE / \|param6: "{ param6 }"\|. WRITE / \|param7: "{ param7 }"\|. WRITE / \|param8: "{ param8 }"\|.
Creating an output field/comment on the selection screen `SELECTION-SCREEN COMMENT`	Creates text content in a field The statement expects a random name (maximum 8 characters; a global variable with type `c` and length 83 is implicitly created) or a text symbol Additions Position-related additions as outlined for `SELECTION-SCREEN ULINE` `FOR FIELD`: Links output field to elements specified with `PARAMETERS` or `SELECT-OPTIONS` `VISIBLE LENGTH`: Defines the visible length of the output field `MODIF ID`: See above.	PROGRAM. &--------------------------------------------------------------------- & Position-related additions &---------------------------------------------------------------------* SELECTION-SCREEN COMMENT /1(20) txt1. SELECTION-SCREEN ULINE /1(50). PARAMETERS: rb1 RADIOBUTTON GROUP rbgr, rb2 RADIOBUTTON GROUP rbgr, rb3 RADIOBUTTON GROUP rbgr. SELECTION-SCREEN ULINE /1(50). SELECTION-SCREEN COMMENT /pos_high(40) txt2. "Providing a text for a parameter SELECTION-SCREEN BEGIN OF LINE. SELECTION-SCREEN COMMENT (15) txt3. PARAMETERS param1 TYPE c LENGTH 10. SELECTION-SCREEN END OF LINE. "Using a text symbol SELECTION-SCREEN COMMENT /1(20) TEXT-001. &--------------------------------------------------------------------- & VISIBLE LENGTH &---------------------------------------------------------------------* SELECTION-SCREEN COMMENT /1(20) txt4 VISIBLE LENGTH 4. &--------------------------------------------------------------------- & MODIF ID &---------------------------------------------------------------------* SELECTION-SCREEN COMMENT /1(50) txt5 MODIF ID mid. SELECTION-SCREEN COMMENT /1(50) txt6. SELECTION-SCREEN COMMENT /1(50) txt7 MODIF ID mid. AT SELECTION-SCREEN OUTPUT. txt1 = 'Make a selection:'. txt2 = 'Text with pos_high'. txt3 = 'Make an entry'. txt4 = 'Some long text'. txt5 = 'First intensified text'. txt6 = 'Not intensified text'. txt7 = 'Second intensified tex'. LOOP AT SCREEN INTO DATA(screen_wa). IF screen_wa-group1 = 'MID'. screen_wa-intensified = '1'. MODIFY SCREEN FROM screen_wa. ENDIF. ENDLOOP. START-OF-SELECTION. WRITE / `Inserted values:`. SKIP. WRITE / \|Radio button selection: "{ COND #( WHEN rb1 IS NOT INITIAL THEN 'rb1' WHEN rb2 IS NOT INITIAL THEN 'rb2' ELSE 'rb3' ) }"\|. WRITE / \|param1: "{ param1 }"\|. IF TEXT-001 IS INITIAL. WRITE / \|Text symbol TEXT-001 does not exist.\|. ENDIF.
Specifying multiple elements in one line and their position in the line `SELECTION-SCREEN BEGIN OF LINE. ... SELECTION-SCREEN END OF LINE.` and `SELECTION-SCREEN POSITION`	Places all `PARAMETERS`, `SELECT-OPTIONS` and `SELECTION-SCREEN` statements in one line without spaces The statement `SELECTION-SCREEN POSITION` can only be specified in the statement block. The position can be specified as number (1-83) or using the additions `POS_LOW` and `POS_HIGH`. The statement relates to positioning the following statement. Note that if there are positioning conflicts, the selection screen cannot be created. In the statement block, certain restrictions apply. See here.	PROGRAM. SELECTION-SCREEN BEGIN OF LINE. SELECTION-SCREEN COMMENT (10) txt1. SELECTION-SCREEN POSITION 15. PARAMETERS param1 TYPE c LENGTH 3. SELECTION-SCREEN COMMENT (10) txt2. SELECTION-SCREEN POSITION 45. PARAMETERS param2 TYPE c LENGTH 3. SELECTION-SCREEN COMMENT (10) txt3. SELECTION-SCREEN POSITION 70. SELECTION-SCREEN COMMENT (10) txt4. SELECTION-SCREEN END OF LINE. DATA dyn_spec TYPE c LENGTH 12. "Chained statement "The example emphasizes potential positioning "conflicts that can prevent the selection screen "from being created. For demo purposes, you can "comment in param3 and run the program, resulting "in a runtime error. Then you can comment in the "NO-EXTENSION and NO INTERVALS additions to the "SELECT-OPTIONS statement, and run the program "again. Since the extra screen elements are not "displayed, the selection screen can be created. SELECTION-SCREEN: BEGIN OF LINE, POSITION 5, COMMENT (10) txt5. SELECT-OPTIONS sel FOR (dyn_spec) "NO-EXTENSION "NO INTERVALS . "PARAMETERS param3 TYPE c LENGTH 3. SELECTION-SCREEN: POSITION 70, COMMENT (10) txt6, END OF LINE. INITIALIZATION. txt1 = 'Some text'. txt2 = 'Hello'. txt3 = sy-uname. txt4 = sy-datum. txt5 = 'Select'. txt6 = 'More text'. dyn_spec = 'SCARR-CARRID'. START-OF-SELECTION. WRITE / `Inserted values:`. SKIP. WRITE / \|param1: "{ param1 }"\|. WRITE / \|param2: "{ param2 }"\|. SKIP. WRITE / `Selection table content:`. LOOP AT sel ASSIGNING FIELD-SYMBOL(<st>). WRITE / \|low: { <st>-low }, high: { <st>-high }, option: { <st>-option }, sign: { <st>-sign }\|. ENDLOOP.
Creating pushbuttons `SELECTION-SCREEN PUSHBUTTON`	Typically, pushbuttons are used to modify the selection screen, not to control the program (e.g. to exit the program). Additions: Position-related additions (see above) `USER-COMMAND`: Used to assign a function code. The pushbutton is enabled by implementing a `TABLES sscrfields.` statement. In doing so, an interface work area is created. When a pushbutton is clicked, the `AT SELECTION-SCREEN` event is raised, and the function code can be evaluated using `sscrfields-ucomm` (do not use `sy-ucomm`). `VISIBLE LENGTH`: Defines the visible length of the pushbutton `MODIF ID`: See above You can use the function module `ICON_CREATE` to assign an icon, a tooltip, and a text to a pushbutton.	PROGRAM. TABLES sscrfields. SELECTION-SCREEN PUSHBUTTON /1(15) btn_a USER-COMMAND cmd1. SELECTION-SCREEN SKIP. SELECTION-SCREEN PUSHBUTTON /1(15) btn_b USER-COMMAND cmd2. SELECTION-SCREEN SKIP. SELECTION-SCREEN PUSHBUTTON /1(30) btn_c USER-COMMAND cmd3 VISIBLE LENGTH 7. INITIALIZATION. btn_a = 'Button A'. btn_c = 'Button C with long text'. CALL FUNCTION 'ICON_CREATE' EXPORTING name = icon_information text = 'Button B' info = 'Some info' IMPORTING result = btn_b EXCEPTIONS OTHERS = 0. AT SELECTION-SCREEN. CASE sscrfields-ucomm. WHEN 'CMD1'. MESSAGE \|Hello { sy-uname }. You clicked button A.\| TYPE 'I'. WHEN 'CMD2'. MESSAGE \|Hello { sy-uname }. You clicked button B.\| TYPE 'I'. WHEN 'CMD3'. MESSAGE \|Hello { sy-uname }. You clicked button C.\| TYPE 'I'. ENDCASE. START-OF-SELECTION. WRITE / `No content to display in this example.`.
Defining a block `SELECTION-SCREEN BEGIN OF BLOCK ... SELECTION-SCREEN END OF BLOCK ...`	You can also create blocks within blocks. The blocks raise the `AT SELECTION-SCREEN ON BLOCK`. There, the entries of a block can be processed together. Additions: `WITH FRAME [TITLE ...]`: Draws a frame round a block. You can optionally specify a title either by specifying a random name or a text symbol. `NO INTERVALS`: When specified, `NO INTERVALS` is used implicitly for `SELECT-OPTIONS` (in all nested blocks).	The code snippet, copyable to a demo program and executable using F8, implements the following: Multiple blocks are created using `SELECTION-SCREEN ... BLOCK ...` statements, including different additions or none. One block contains nested blocks. The raising of `AT SELECTION-SCREEN ON BLOCK` events for the blocks defined is demonstrated using messages displayed when the program is run. PROGRAM. &--------------------------------------------------------------------- & No addition &---------------------------------------------------------------------* SELECTION-SCREEN BEGIN OF BLOCK block1. PARAMETERS param1 TYPE c LENGTH 10 DEFAULT 'abc' LOWER CASE. PARAMETERS param2 TYPE c LENGTH 10 DEFAULT 'def' LOWER CASE. SELECTION-SCREEN END OF BLOCK block1. &--------------------------------------------------------------------- & WITH FRAME &---------------------------------------------------------------------* SELECTION-SCREEN BEGIN OF BLOCK block2 WITH FRAME. PARAMETERS param3 TYPE c LENGTH 10 DEFAULT 'hij' LOWER CASE. PARAMETERS param4 TYPE c LENGTH 10 DEFAULT 'klm' LOWER CASE. SELECTION-SCREEN END OF BLOCK block2. &--------------------------------------------------------------------- & WITH FRAME WITH TITLE &---------------------------------------------------------------------* SELECTION-SCREEN BEGIN OF BLOCK block3 WITH FRAME TITLE titl. PARAMETERS: rb1 RADIOBUTTON GROUP gr, rb2 RADIOBUTTON GROUP gr, rb3 RADIOBUTTON GROUP gr. SELECTION-SCREEN END OF BLOCK block3. &--------------------------------------------------------------------- & Nested blocks &---------------------------------------------------------------------* SELECTION-SCREEN BEGIN OF BLOCK block4a WITH FRAME TITLE titl4a. PARAMETERS param5 TYPE c LENGTH 10 DEFAULT 'nop' LOWER CASE. SELECTION-SCREEN SKIP. SELECTION-SCREEN BEGIN OF BLOCK block4b WITH FRAME TITLE titl4b. PARAMETERS param6 TYPE c LENGTH 10 DEFAULT 'qrs' LOWER CASE. SELECTION-SCREEN SKIP. SELECTION-SCREEN BEGIN OF BLOCK block4c WITH FRAME TITLE titl4c. PARAMETERS param7 TYPE c LENGTH 10 DEFAULT 'tuv' LOWER CASE. SELECTION-SCREEN SKIP. SELECTION-SCREEN END OF BLOCK block4c. SELECTION-SCREEN END OF BLOCK block4b. SELECTION-SCREEN END OF BLOCK block4a. "Demo flags for the AT SELECTION-SCREEN ON BLOCK implementations DATA block1_flag TYPE abap_boolean. DATA block2_flag TYPE abap_boolean. DATA block3_flag TYPE abap_boolean. DATA block4a_flag TYPE abap_boolean. DATA block4b_flag TYPE abap_boolean. DATA block4c_flag TYPE abap_boolean. INITIALIZATION. titl = 'Radiobutton Selection'. titl4a = 'Title 1'. titl4b = 'Title 2'. titl4c = 'Title 3'. AT SELECTION-SCREEN ON BLOCK block1. block1_flag = abap_true. MESSAGE \|Event AT SELECTION-SCREEN ON BLOCK block1 raised. Others already raised? \| && \|block2: "{ COND #( WHEN block2_flag = abap_true THEN abap_true ) }" \| && \|block3: "{ COND #( WHEN block3_flag = abap_true THEN abap_true ) }" \| && \|block4a: "{ COND #( WHEN block4a_flag = abap_true THEN abap_true ) }" \| && \|block4b: "{ COND #( WHEN block4b_flag = abap_true THEN abap_true ) }" \| && \|block4c: "{ COND #( WHEN block4c_flag = abap_true THEN abap_true ) }" \| TYPE 'I'. AT SELECTION-SCREEN ON BLOCK block2. block2_flag = abap_true. MESSAGE \|Event AT SELECTION-SCREEN ON BLOCK block2 raised. Others already raised? \| && \|block1: "{ COND #( WHEN block1_flag = abap_true THEN abap_true ) }" \| && \|block3: "{ COND #( WHEN block3_flag = abap_true THEN abap_true ) }" \| && \|block4a: "{ COND #( WHEN block4a_flag = abap_true THEN abap_true ) }" \| && \|block4b: "{ COND #( WHEN block4b_flag = abap_true THEN abap_true ) }" \| && \|block4c: "{ COND #( WHEN block4c_flag = abap_true THEN abap_true ) }" \| TYPE 'I'. AT SELECTION-SCREEN ON BLOCK block3. block3_flag = abap_true. MESSAGE \|Event AT SELECTION-SCREEN ON BLOCK block3 raised. Others already raised? \| && \|block1: "{ COND #( WHEN block1_flag = abap_true THEN abap_true ) }" \| && \|block2: "{ COND #( WHEN block2_flag = abap_true THEN abap_true ) }" \| && \|block4a: "{ COND #( WHEN block4a_flag = abap_true THEN abap_true ) }" \| && \|block4b: "{ COND #( WHEN block4b_flag = abap_true THEN abap_true ) }" \| && \|block4c: "{ COND #( WHEN block4c_flag = abap_true THEN abap_true ) }" \| TYPE 'I'. AT SELECTION-SCREEN ON BLOCK block4a. block4a_flag = abap_true. MESSAGE \|Event AT SELECTION-SCREEN ON BLOCK block4a raised. Others already raised? \| && \|block1: "{ COND #( WHEN block1_flag = abap_true THEN abap_true ) }" \| && \|block2: "{ COND #( WHEN block2_flag = abap_true THEN abap_true ) }" \| && \|block3: "{ COND #( WHEN block3_flag = abap_true THEN abap_true ) }" \| && \|block4b: "{ COND #( WHEN block4b_flag = abap_true THEN abap_true ) }" \| && \|block4c: "{ COND #( WHEN block4c_flag = abap_true THEN abap_true ) }" \| TYPE 'I'. AT SELECTION-SCREEN ON BLOCK block4b. block4b_flag = abap_true. MESSAGE \|Event AT SELECTION-SCREEN ON BLOCK block4b raised. Others already raised? \| && \|block1: "{ COND #( WHEN block1_flag = abap_true THEN abap_true ) }" \| && \|block2: "{ COND #( WHEN block2_flag = abap_true THEN abap_true ) }" \| && \|block3: "{ COND #( WHEN block3_flag = abap_true THEN abap_true ) }" \| && \|block4a: "{ COND #( WHEN block4a_flag = abap_true THEN abap_true ) }" \| && \|block4c: "{ COND #( WHEN block4c_flag = abap_true THEN abap_true ) }" \| TYPE 'I'. AT SELECTION-SCREEN ON BLOCK block4c. block4c_flag = abap_true. MESSAGE \|Event AT SELECTION-SCREEN ON BLOCK block4c raised. Others already raised? \| && \|block1: "{ COND #( WHEN block1_flag = abap_true THEN abap_true ) }" \| && \|block2: "{ COND #( WHEN block2_flag = abap_true THEN abap_true ) }" \| && \|block3: "{ COND #( WHEN block3_flag = abap_true THEN abap_true ) }" \| && \|block4a: "{ COND #( WHEN block4a_flag = abap_true THEN abap_true ) }" \| && \|block4b: "{ COND #( WHEN block4b_flag = abap_true THEN abap_true ) }" \| TYPE 'I'. START-OF-SELECTION. WRITE / `Inserted values:`. SKIP. WRITE / \|param1: "{ param1 }"\|. WRITE / \|param2: "{ param2 }"\|. WRITE / \|param3: "{ param3 }"\|. WRITE / \|param4: "{ param4 }"\|. WRITE / \|param5: "{ param5 }"\|. WRITE / \|param6: "{ param6 }"\|. WRITE / \|param7: "{ param7 }"\|.
Defining tabstrips `SELECTION-SCREEN BEGIN OF TABBED BLOCK ... SELECTION-SCREEN END OF BLOCK ...` and `SELECTION-SCREEN TAB`	Within the statement block, you can only specify `SELECTION-SCREEN ... TAB ...` statements (they define tab titles). Additions to `... TABBED BLOCK ...` statements: `FOR ... LINES`: Defines the number of lines in the tabstrip area `NO INTERVALS`: To narrow the size for subscreen dynpros. Additions to `... TAB ...` statements: `(...)`: Length specification `USER-COMMAND`: To assign a function code. See above. `DEFAULT [PROGRAM ...] SCREEN`: The tab titles must be assigned a subscreen dynpro. For the tabstrip areas, structures are implicitly created having the specified name. They have 3 components: `prog`, `dynnr` and `activetab`. Not specifying `DEFAULT ...` means the values must be passed before the selection screen is sent. Find here more information. `MODIF ID`: See above	See the example for `SELECTION-SCREEN BEGIN OF SCREEN ... AS SUBSCREEN` that uses `... TABBED BLOCK ...` and `... TAB ...` statements.
Adding pushbuttons in the application toolbar `SELECTION-SCREEN FUNCTION KEY`	The statement activates pushbuttons in the application toolbar for specific function codes (`FC0n`). There are five inactive pushbuttons to which the function codes `FC01`, `FC02` up to `FC05` are assigned. To enable the pushbutton, include the `TABLES sscrfields.` statement in the code for the interface work area. When the button is clicked, the `AT SELECTION-SCREEN` event is raised and the function code is passed to `sscrfields-ucomm`, which can be evaluated and reacted upon accordingly.	The code snippet, copyable to a demo program and executable using F8, implements the following: Five pushbuttons are added to the application toolbar. To provide text for the buttons, values are assigned to the `sscrfields-functxt_0n` component. In the `AT SELECTION-SCREEN` event block, `sscrfields-ucomm` is evaluated. Depending on the function code, parameter values are assigned or messages are raised for demonstration purposes. PROGRAM. TABLES sscrfields. PARAMETERS param1 TYPE c LENGTH 20. PARAMETERS param2 TYPE c LENGTH 20. PARAMETERS param3 TYPE c LENGTH 20. SELECTION-SCREEN: FUNCTION KEY 1, "Stands for FC01 FUNCTION KEY 2, "FC02 FUNCTION KEY 3, "FC03 FUNCTION KEY 4, "FC04 FUNCTION KEY 5. "FC05 INITIALIZATION. sscrfields-functxt_01 = 'Insert name'. sscrfields-functxt_02 = 'Insert time'. sscrfields-functxt_03 = 'Insert date'. sscrfields-functxt_04 = 'Say hi'. sscrfields-functxt_05 = 'Error message'. AT SELECTION-SCREEN. CASE sscrfields-ucomm. WHEN 'FC01'. param1 = sy-uname. WHEN 'FC02'. param2 = sy-uzeit. WHEN 'FC03'. param3 = sy-datum. WHEN 'FC04'. MESSAGE \|Hello { sy-uname }. You clicked the fourth button.\| TYPE 'I'. WHEN 'FC05'. MESSAGE \|Error message raised by clicking the fifth button.\| TYPE 'E'. ENDCASE. START-OF-SELECTION. WRITE / `Inserted values:`. SKIP. WRITE / \|param1: "{ param1 }"\|. WRITE / \|param2: "{ param2 }"\|. WRITE / \|param3: "{ param3 }"\|.

Subject/Addition	Notes	Code Snippet
Writing content	You can write flat data objects (including flat structures with character-like components), data objects of type `string` and `xstring` and enumerated types. Also writable: result of function calls, string expressions and method calls Writing expressions in string templates: They are useful for writing embedded arithmetic or bit expressions as these cannot be specified directly. Note that control characters such as `\n` for new lines are ignored. Positioning options are avaialble (see below) for the `WRITE` statement. Among them is `/` that places the output in the next line. Not specifying it means the output is written in the same line.	"Writing in the same line "The example uses a character literal, i.e. an unnamed data object. "Note that there is a separating blank in the list output. WRITE 'Hello'. WRITE 'world'. "Using named data objects and string expressions DATA some_text TYPE string VALUE `Hi`. WRITE some_text && `, ` && sy-uname && `.`. "Writing to a new line with / WRITE / 'New line'. "More flat data objects "Note the default positioning of the output regarding "the numeric types. WRITE / CONV decfloat34( '1.23456789' ). TYPES n5 TYPE n LENGTH 5. DATA numc5 TYPE n5 VALUE '12345'. WRITE / numc5. DATA number TYPE i VALUE 123. WRITE / number. "Flat structure with character-like components "Note the conversion rules. DATA: BEGIN OF flat_struc, comp1 TYPE c LENGTH 4 VALUE `ABAP`, comp2 TYPE n LENGTH 3 VALUE '987', comp3 TYPE abap_boolean VALUE 'X', comp4 TYPE d VALUE '20250101', comp5 TYPE t VALUE '123456', END OF flat_struc. WRITE / flat_struc. "String templates WRITE / \|Today's date is { sy-datum }.\|. "Formatting options with string templates WRITE / \|{ sy-uname WIDTH = 20 ALIGN = RIGHT CASE = LOWER }\|. "Arithmetic expressions cannot be specified directly. You may use "the expressions in string templates. "WRITE / 1 + 2. WRITE / \|{ 1 + 2 }\|. WRITE / \|{ CONV decfloat34( 1 / 3 ) DECIMALS = 3 }\|. "Concatenating using && WRITE / `conc` && `atenated`. "Function calls "Note: You can use chained statements with a colon. WRITE: / to_upper( 'abap' ), / repeat( val = `` occ = 50 ), / replace( val = `He##o wor#d` sub = `#` with = `l` occ = 0 ). "Result of method calls "The example uses the retrieval of a random integer between 1 and 10 WRITE / cl_abap_random_int=>create( seed = cl_abap_random=>seed( ) min = 1 max = 10 )->get_next( ). "Note the specification. The returned value is of type i. Specifying * "for the length means the length required to output the current value "is used. WRITE /(*) cl_abap_random_int=>create( seed = cl_abap_random=>seed( ) min = 1 max = 10 )->get_next( ).
Positioning options (1) Additions `/`, `AT ... position(length\|\|*)`	`/`: Places the output in the next line. Not specifying it means the output is written in the same line. `AT`: Explicitly specifying the output position and length `AT` can be omitted if the position and length are specified as numeric literals. The position should not be greater than the list width; otherwise, there is not output. A value less than 1 is ignored. The length value should also be between 1 and the list width. The length specifications `` and `` have characteristics specific to data types that are output. They are particularly useful for ensuring that all characters are output (``: minimum output: `**`: maximum output). Find information in the documentation and here regarding the output length. `WRITE /.` works like `SKIP.`.	&--------------------------------------------------------------------- & WRITE with and without / &---------------------------------------------------------------------* "Writing output with and without specifying / WRITE 'Hello'. WRITE 'world'. WRITE / 'new line'. &--------------------------------------------------------------------- & Specifying the output position with(out) AT, position and length &---------------------------------------------------------------------* WRITE / repeat( val = `` occ = 80 ). "WRITE statement working like SKIP. WRITE /. "Specifying the output position, a length and new line "specification WRITE 20 'test'. "Note the overwriting in the following example. WRITE / 'Lorem ipsum dolor sit amet'. WRITE 10 '####'. "Specifying the length, ommitting position specification "This means that the output is written from the first column on. WRITE /(10) 'Not displayed completely'. "Specifying both length and position WRITE /5(30) 'This text displayed completely starting from position 5.'. "The AT addition can only be ommitted if position and length are specified "as numeric literals as above. WRITE AT /3(20) 'lorem ipsum'. WRITE /3(20) 'dolor sit amet'. "AT specification required DATA position TYPE i VALUE 10. DATA length TYPE i VALUE 50. WRITE AT /position(length) \|This text is starts from position { position }. Length specification { length }.\|. "Length specifications with or *. In that case, the output length "depends on the data type of the data object. There are special rules. "See the ABAP Keyword Documentation for the details. "Example with type c DATA hi TYPE c LENGTH 10 VALUE 'Hello '. WRITE: / hi, sy-uname. "Minimum output (trailing blanks are ignored) WRITE: /() hi, sy-uname. "Maximum output (doubled length of data object) WRITE: /(*) hi, sy-uname. "Example with type i DATA some_number TYPE i VALUE 123. WRITE: / some_number, '<- some_number'. "Minimum length required to output content WRITE: /() some_number, '<- some_number'. "Maximum length to output content WRITE: /(*) some_number, '<- some_number'. "Example with type p DATA some_packed_number TYPE p LENGTH 16 DECIMALS 14 VALUE '-123.4567890'. WRITE: / some_packed_number, '<- some_packed_number'. "Minimum length required to output content including separators WRITE: /() some_packed_number, '<- some_packed_number'. "Maximum length to output content including signs and separators WRITE: /(**) some_packed_number, '<- some_packed_number'.
Positioning options (2) Additions `NO-GAP`, `UNDER`	`NO-GAP`: Positions directly after the output `UNDER`: Output in the position of previous output	&--------------------------------------------------------------------- & NO-GAP &---------------------------------------------------------------------* WRITE / repeat( val = `` occ = 80 ). "Output: AB AP WRITE / 'AB'. WRITE 'AP'. "Output: ABAP WRITE: / 'AB' NO-GAP. WRITE 'AP'. &---------------------------------------------------------------------* & UNDER &---------------------------------------------------------------------* WRITE / repeat( val = `*` occ = 80 ). "Note: If the output is written in the same line in which the previous output "is displayed, this output is overwritten. DATA abc TYPE c LENGTH 5 VALUE 'abcde'. WRITE /5(5) abc. WRITE / 'fghij' UNDER abc. "Output in tabular form DATA: carrid TYPE scarr-carrid, carrname TYPE scarr-carrname, currcode TYPE scarr-currcode, url TYPE scarr-url. WRITE: /3 'Carrier', 12 'Name', 35 'Currency Code', 50 'URL'. WRITE / repeat( val = `=` occ = 80 ). SELECT carrid, carrname, currcode, url FROM scarr INTO @DATA(scarr_wa). WRITE: / scarr_wa-carrid UNDER 'Carrier', scarr_wa-carrname UNDER 'Name', scarr_wa-currcode UNDER 'Currency Code', scarr_wa-url UNDER 'URL'. ENDSELECT. WRITE / . "Excursion: Writing an internal table in table-like fashion. As a prerequisite, "all values are convertible to type string. The following example does not use "UNDER, but calculates position and length values. It is an exploration and not "meant to present a best practice example, particularly because other options "such as ALV are available for that purpose. It may not be suitable for each "line and component type. "Demo internal table TYPES: BEGIN OF demo_struc, chars TYPE c LENGTH 5, num TYPE i, dec TYPE decfloat34, text TYPE string, flag TYPE abap_boolean, date TYPE d, END OF demo_struc, ty_tab TYPE TABLE OF demo_struc WITH EMPTY KEY. DATA(itab) = VALUE ty_tab( ( chars = 'a' num = 123 dec = CONV decfloat34( '-123.456' ) text = `Hello world` flag = abap_true date = CONV d( '20250101' ) ) ( chars = 'bcd' num = 4 dec = CONV decfloat34( '7.8945612' ) text = `Lorem ipsum` flag = abap_false date = CONV d( '20251227' ) ) ( chars = 'efghi' num = 987654 dec = CONV decfloat34( '1.01' ) text = `ABAP` flag = abap_true date = CONV d( '20250621' ) ) ( chars = 'jk' num = 321 dec = CONV decfloat34( '0.00000000000001' ) text = `test` flag = abap_true date = CONV d( '20251015' ) ) ). TYPES: BEGIN OF comp_struc, name TYPE string, len TYPE i, off TYPE i, dref TYPE REF TO string, END OF comp_struc. DATA it_comps TYPE TABLE OF comp_struc WITH EMPTY KEY. DATA str TYPE string. TRY. DATA(type_descr_obj_tab) = CAST cl_abap_tabledescr( cl_abap_typedescr=>describe_by_data( itab ) ). DATA(tab_comps) = CAST cl_abap_structdescr( type_descr_obj_tab->get_table_line_type( ) )->get_components( ). LOOP AT tab_comps ASSIGNING FIELD-SYMBOL(<comp>). APPEND VALUE #( name = <comp>-name len = strlen( <comp>-name ) ) TO it_comps. ENDLOOP. CATCH cx_sy_move_cast_error INTO DATA(error). WRITE / error->get_text( ). ENDTRY. IF error IS INITIAL. "Implementation for properly aligning the content "The example is implemented to check the length of the column names as well as the "length of the values in the columns. It determines the length of the longest string "in each column. Depending on the length values, either the length of the column name "or the length of the longest string in a column is stored in an internal table that "contains information for calculating the offset. LOOP AT tab_comps ASSIGNING FIELD-SYMBOL(<len>). ASSIGN it_comps[ name = <len>-name ] TO FIELD-SYMBOL(<co>). DATA(max_content) = REDUCE i( INIT len = <co>-len FOR <line> IN itab NEXT len = COND #( LET lv = \|{ <line>-(<co>-name) }\| IN WHEN strlen( lv ) > len THEN strlen( lv ) ELSE len ) ). "Extend the length value to leave some more space IF max_content > <co>-len. <co>-len = max_content + 3. ELSE. <co>-len += 3. ENDIF. ENDLOOP. "Calculating offset values DATA max_str_len TYPE i. LOOP AT it_comps ASSIGNING FIELD-SYMBOL(<off>). DATA(tabix) = sy-tabix. READ TABLE it_comps INDEX tabix - 1 ASSIGNING FIELD-SYMBOL(<prev>). <off>-off = COND #( WHEN tabix = 1 THEN 0 ELSE <prev>-len + <prev>-off ). max_str_len += <off>-len. ENDLOOP. "Providing enough space so that table row content can be inserted based on "the offset specification SHIFT str BY max_str_len PLACES RIGHT. "Adding the column names first LOOP AT it_comps ASSIGNING FIELD-SYMBOL(<header>). str = insert( val = str sub = <header>-name off = <header>-off ). ENDLOOP. WRITE / str. "Processing all lines in the internal table containing the retrieved table rows LOOP AT itab ASSIGNING FIELD-SYMBOL(<wa>). CLEAR str. SHIFT str BY max_str_len PLACES RIGHT. DO. TRY. str = insert( val = str sub = <wa>-(sy-index) off = it_comps[ sy-index ]-off ). CATCH cx_sy_assign_illegal_component cx_sy_range_out_of_bounds cx_sy_itab_line_not_found. EXIT. ENDTRY. ENDDO. WRITE / str. ENDLOOP. ENDIF.
Adding quickinfo Addition `QUICKINFO`	Creates a tooltip for the output	WRITE / repeat( val = `` occ = 80 ). WRITE / 'Place the cursor on the following output and check the tooltip:'. WRITE: /() sy-uname QUICKINFO 'User name', '/', () sy-datum QUICKINFO 'Current date', '/', () sy-uzeit QUICKINFO 'Current time'.
Adding list elements such as checkboxes, icons, symbols, and frames Additions `AS CHECKBOX`, `AS ICON`, `AS SYMBOL`, `AS LINE`	`AS CHECKBOX`: The value (blank, or `X`) is stored in the list buffer and can be evaluated during a list event. `AS ICON`: Outputs icons. Check the type pool `ICON` for names of predefined icons. `AS SYMBOL`: Outputs symbols. Check the type pool `SYM` for names of predefined symbols. `AS LINE`: Outputs corners, crosses, lines, and T sections. Check the type pool `LINE` for names of predefined options.	PROGRAM. DATA: flag TYPE c LENGTH 1, checkbox_name TYPE c LENGTH 10, wa TYPE c LENGTH 20. START-OF-SELECTION. &--------------------------------------------------------------------- & AS CHECKBOX &---------------------------------------------------------------------* DO 5 TIMES. checkbox_name = \|Checkbox { sy-index }\|. WRITE: / flag AS CHECKBOX, (10) checkbox_name. ENDDO. &--------------------------------------------------------------------- & AS ICON &---------------------------------------------------------------------* WRITE / icon_green_light AS ICON. WRITE / icon_red_light AS ICON. WRITE / icon_yellow_light AS ICON. WRITE / icon_activate AS ICON. &--------------------------------------------------------------------- & AS SYMBOL &---------------------------------------------------------------------* WRITE / sym_left_hand AS SYMBOL. WRITE / sym_caution AS SYMBOL. &--------------------------------------------------------------------- & AS LINE &---------------------------------------------------------------------* WRITE / line_horizontal_line AS LINE NO-GAP. WRITE line_space AS LINE NO-GAP. WRITE line_vertical_line AS LINE. &--------------------------------------------------------------------- & Evaluating the checkbox selections &---------------------------------------------------------------------* AT LINE-SELECTION. WRITE / \|You clicked line { sy-lilli }. \|. WRITE / `Selected checkboxes:`. DO. READ LINE sy-index FIELD VALUE flag checkbox_name INTO wa. IF sy-subrc <> 0. EXIT. ELSEIF flag = 'X'. WRITE / wa. ENDIF. CLEAR wa. ENDDO.
Formatting options	Various additions are available to format output. For example, they deal with aligning content, currency, unit, date and time-related formatting, among others. Find more information in the ABAP Keyword Documentation here and here. See also the `FORMAT` statement.	The example only shows a selection. Check the documentation for all additions. &--------------------------------------------------------------------- & Additions for aligning content &---------------------------------------------------------------------* WRITE /(10) 'X' RIGHT-JUSTIFIED. "' X' WRITE /(10) 'X' CENTERED. "' X ' WRITE /(10) 'X' LEFT-JUSTIFIED. "'X ' &--------------------------------------------------------------------- & NO-ZERO &---------------------------------------------------------------------* DATA: numc10 TYPE n LENGTH 10 VALUE '123'. WRITE /(10) numc10. WRITE /(10) numc10 NO-ZERO. &--------------------------------------------------------------------- & DECIMALS &---------------------------------------------------------------------* DATA: packed_num TYPE p LENGTH 8 DECIMALS 4 VALUE '9876.5432'. WRITE /() packed_num. WRITE /() packed_num DECIMALS 2. &--------------------------------------------------------------------- & COLOR &---------------------------------------------------------------------* "The commented out value stands for the value that can also "be directly specified in the syntax (except 0) or contained in "a data object. There are several additions with many options. WRITE / 'COL_BACKGROUND (0)' COLOR COL_BACKGROUND. "0 (GUI dependent) WRITE / 'COL_HEADING (1)' COLOR COL_HEADING. "1 (gray-blue) WRITE / 'COL_HEADING (1)' COLOR 1. WRITE / 'COL_NORMAL (2)' COLOR COL_NORMAL. "2 (light gray) WRITE / 'COL_TOTAL (3)' COLOR COL_TOTAL. "3 (yellow) WRITE / 'COL_KEY (4)' COLOR COL_KEY. "4 (blue-green) WRITE / 'COL_POSITIVE (5)' COLOR COL_POSITIVE. "5 (green) WRITE / 'COL_NEGATIVE (6)' COLOR COL_NEGATIVE. "6 (red) WRITE / 'COL_GROUP (7)' COLOR COL_GROUP. "7 (orange) WRITE / 'COLOR 7 OFF' COLOR 7 OFF. "default color "Setting the intensity of the background color. "Note that many of the following additions can specify further "additions such as ON and OFF. See the details in the documentation. WRITE / 'COLOR 7 INTENSIFIED OFF' COLOR 7 INTENSIFIED OFF. "INVERSE: When ON, the foreground, i.e. the output is displayed "in the selected color WRITE / 'COLOR 7 INVERSE ON' COLOR 7 INVERSE ON.

Subject/Addition	Notes	Code Snippet
Coloring output `COLOR` addition	As shown above, multiple colors are available. Instead of `COL_*`, the numbers that represent the color specifications can also be specified.	`FORMAT COLOR COL_POSITIVE. WRITE / 'ABC'. WRITE / 'DEF'. WRITE / 'GHI'. FORMAT COLOR OFF. WRITE / 'JKL'. WRITE / 'MNO'. FORMAT COLOR COL_KEY. WRITE / 'PQR'. WRITE / 'STU'. FORMAT COLOR OFF. WRITE / 'VWX'. WRITE / 'YZ'.`
Specifying a hotspot `HOTSPOT` addition	Displays the mouse pointer when hovering over an element. Here, a single click has then the same effect as a double click (i.e. the selection of function key F2).	PROGRAM. START-OF-SELECTION. FORMAT HOTSPOT. DO 5 TIMES. WRITE / \|{ sy-index } - some clickable colored text showing the mouse pointer.\| COLOR 5. ENDDO. FORMAT HOTSPOT OFF. WRITE / `Some colored text that doesn't show the mouse pointer.` COLOR 6. AT LINE-SELECTION. WRITE \|You clicked line { sy-lilli }.\|.
Specifying an input field `INPUT` addition	Enables user input that can be evaluated during a list event.	`PROGRAM. DATA: some_text TYPE c LENGTH 100, line_number TYPE i. START-OF-SELECTION. WRITE 'Make an entry:'. "Note: The input field is currently empty. Without the following statement, "the input field would not be displayed. SET BLANK LINES ON. FORMAT INPUT. WRITE / some_text. FORMAT INPUT OFF. WRITE / 'Submit' COLOR 5 HOTSPOT. AT LINE-SELECTION. IF sy-lisel = 'Submit'. line_number = sy-lilli - 1. READ LINE line_number FIELD VALUE some_text. WRITE: 'Your entry:', / some_text. ENDIF.`
Creating frames `FRAME` addition	Defines whether the - and \| characters are converted to line elements, producing continuous lines.	`FORMAT FRAMES ON. WRITE: / '----', / '\| \|', / '----'. FORMAT FRAMES OFF.`
Resetting formats `RESET` addition	This addition sets all formatting settings for which the corresponding addition is not specified in the same `FORMAT` statement to the state `OFF` (exception: `FRAMES`).	In the following example, all settings are reset without specifying concrete additions (e.g. `INVERSE OFF`). Note the effects of such a statement (e.g. `INTENSIFIED` is `ON` by default at program start. Now it is set to `OFF`. See the ABAP Keyword Documentation for more information. `WRITE / 'ABCD'. FORMAT COLOR 7 INVERSE ON. WRITE / 'DEFG'. WRITE / 'HIJK'. FORMAT RESET. WRITE / 'LMNO'.`

Subject/Keyword	Notes	Code Snippet
Creating a horizontal line `ULINE`	Additions are available such as for position and length.	`ULINE. ULINE AT 5(20).`
Specifying if blank lines created using `WRITE` are displayed `SET BLANK LINES`	The statement must be specified with the additions `ON` and `OFF`. Note that blank lines are not displayed by default.	DATA(itab) = VALUE string_table( ( `a` ) ( `b` ) ( `` ) ( `` ) ( `c` ) ( `` ) ( `d` ) ). "Blank lines not output by default LOOP AT itab INTO DATA(wa). WRITE / wa. ENDLOOP. WRITE / repeat( val = `` occ = 80 ). "Explicitly specifying that blank lines should not be output SET BLANK LINES OFF. LOOP AT itab INTO wa. WRITE / wa. ENDLOOP. WRITE / repeat( val = `` occ = 80 ). "Blank lines are output SET BLANK LINES ON. LOOP AT itab INTO wa. WRITE / wa. ENDLOOP.
Setting the list cursor explicitly in another line `SKIP`, `SKIP TO LINE`	You can create blank lines, but also set to the cursor to a specified line.	&--------------------------------------------------------------------- & Creating blank lines &---------------------------------------------------------------------* WRITE / 'abc'. "Skips 1 line SKIP. WRITE / 'def'. "Specifying the number of lines to be skipped SKIP 3. WRITE / 'ghi'. SKIP. &--------------------------------------------------------------------- & Positioning the list cursor in another line &---------------------------------------------------------------------* "In the example, the list cursor is explicitly set to "a particular number. Here, B and C are not output (i.e. "overwritten with the output that follows). WRITE / 'Text A'. WRITE / 'Text B'. "The line number of the previous WRITE is retrieved. DATA(line) = sy-linno. WRITE / 'Text C'. SKIP TO LINE line. WRITE / 'Text D'. WRITE / 'Text E'. WRITE / 'Text F'.
Setting the list cursor to the first position of the next line `NEW-LINE`	Additions are available to affect the scrolling behavior	`WRITE / 'Next statement is NEW-LINE'. NEW-LINE. "The following output is in a new line. WRITE 'WRITE statement without /'.`
Storing the content of a flat variable together with the current list line `HIDE`	You can read the stored content again during a list event. Find more information here.	PROGRAM. TYPES: BEGIN OF s, num1 TYPE i, num2 TYPE i, END OF s, ty_int_tab TYPE TABLE OF s WITH EMPTY KEY. DATA(itab) = VALUE ty_int_tab( ( num1 = 10 num2 = 5 ) ( num1 = 2346 num2 = 3475 ) ( num1 = 2 num2 = 4 ) ( num1 = 347 num2 = 823 ) ( num1 = 20 num2 = 54 ) ). DATA: addition_result TYPE i. START-OF-SELECTION. FORMAT HOTSPOT. LOOP AT itab INTO DATA(wa). addition_result = wa-num1 + wa-num2. WRITE / \|{ wa-num1 } + { wa-num2 } = ...\|. HIDE: addition_result. ENDLOOP. AT LINE-SELECTION. WRITE (*) addition_result.
Creating a page break `RESERVE n LINES`	Relevant if there's not sufficient space on the list page between the last output and page end or footer. The page break creation raises the `END-OF-PAGE` event. Has an impact on the behavior of `BACK` statements as shown below.	The following example creates multiple lines in a loop. Additions to `REPORT` are used to cater for the example demonstration with a small page length: `NO STANDARD PAGE HEADING` suppresses the output of the standard page header in the basic list `LINE-COUNT` determines the page length. The number of lines in parentheses stands for the number of lines in the page footer. The footer can be defined in the `END-OF-PAGE` block. Find more information here. Due to the `RESERVE` statement, page breaks are created as there is not enough space left on the page. The loop writes 4 sample texts to the list and can be considered a line block. They should not be separated by page breaks. You can try and comment out the line with the `RESERVE` statement to check out the difference. `REPORT NO STANDARD PAGE HEADING LINE-COUNT 7(2). START-OF-SELECTION. DO 5 TIMES. RESERVE 4 LINES. WRITE: / 'text a', / 'text b', / 'text c', / 'text d'. ENDDO. END-OF-PAGE. WRITE \|--- { sy-pagno } ---\|.`
Positioning the list cursor in the first position of the first line of a logical unit `BACK`	Such a logical unit can be a line block determined using `RESERVE` Find more information here.	The following example demonstrates `BACK` with `RESERVE`. Consider the `RESERVE 5 LINES` statements as defining a block of 5 lines. When using `BACK` after `RESERVE`, e.g. after a loop, you can put the suqsequent output to the first line of this block of lines. `DATA int_for_back TYPE i. WRITE / 'RESERVE without BACK:'. int_for_back = sy-colno. ULINE AT /(int_for_back). RESERVE 5 LINES. DO 5 TIMES. WRITE / sy-index. ENDDO. int_for_back = sy-colno. WRITE AT int_for_back ' <- This is not number 1.'. SKIP. WRITE / 'RESERVE with BACK:'. int_for_back = sy-colno. ULINE AT /(int_for_back). RESERVE 5 LINES. DO 5 TIMES. WRITE / sy-index. ENDDO. int_for_back = sy-colno. BACK. WRITE AT int_for_back ' <- This should be number 1.'.`

Event block	Notes	Code Snippet
Program constructor	`LOAD-OF-PROGRAM` Called when a program is loaded into the internal session Can be used to initialize the global data of a program. However, for executable programs, it is recommended that you use the event block `INITIALIZATION` for this task since the start values for parameters and selection criteria are set after `LOAD-OF-PROGRAM`.	See below
Reporting events related to executable programs in particular	`INITIALIZATION` Used to initialize executable programs and provide start values (that cannot be statically expressed using `DEFAULT`) Called directly after `LOAD-OF-PROGRAM` and before selection screen processing `START-OF-SELECTION` Called after selection screen processing (see the following event blocks) If an executable program does not contain selection screens, this block is called automatically and implicitly. All statements are implicitly assigned to this block unless they are explicitly assigned to another block. Although it is optional, it is recommended that you specify the statement explicitly to improve readability.	PROGRAM. TYPES: BEGIN OF st, id TYPE c LENGTH 3, event_block TYPE c LENGTH 50, time TYPE utclong, END OF st. DATA log TYPE TABLE OF st WITH EMPTY KEY. DATA counter TYPE i. SELECTION-SCREEN BEGIN OF LINE. SELECTION-SCREEN COMMENT (10) txt1. PARAMETERS text1 TYPE c LENGTH 10 LOWER CASE. SELECTION-SCREEN END OF LINE. SELECTION-SCREEN BEGIN OF LINE. SELECTION-SCREEN COMMENT (10) txt2. PARAMETERS text2 TYPE c LENGTH 10 LOWER CASE. SELECTION-SCREEN END OF LINE. LOAD-OF-PROGRAM. counter += 1. APPEND VALUE #( id = counter event_block = `LOAD-OF-PROGRAM` time = utclong_current( ) ) TO log. INITIALIZATION. counter += 1. APPEND VALUE #( id = counter event_block = `INITIALIZATION` time = utclong_current( ) ) TO log. text1 = 'Hello'. text2 = 'World'. txt1 = 'Text 1'. txt2 = 'Text 2'. START-OF-SELECTION. counter += 1. APPEND VALUE #( id = counter event_block = `START-OF-SELECTION` time = utclong_current( ) ) TO log. LOOP AT log INTO DATA(wa). WRITE: /(*) wa-id, (20) wa-event_block, (40) wa-time. ENDLOOP.
Selection screen events	Used to individually evaluate selection screen elements, e.g. a specific parameter. In many cases, the events can be used for input validation (this should not wait until `START-OF-SELECTION`). If your custom input validation fails on an input, you can raise a message (e.g. a message of type `E`: `MESSAGE 'Error' TYPE 'E'.`) and allow users to edit the input again. Event blocks: `AT SELECTION-SCREEN OUTPUT`: Called by the dynpro event PBO of a selection screen after `INITIALIZATION`; can be used for modifying screen elements (e.g. using `MODIFY SCREEN`) `AT SELECTION-SCREEN ON par`: Called when values for a parameter or selection criteria were passed to the program; note: the syntax is also available for selection criteria; an additional variant `... ON END OF ...` is available (this event block is called when the selection table is passed completely allowing to check the entire selection table content) `AT SELECTION-SCREEN ON BLOCK bl`: Called when all input for a block is passed to the program `AT SELECTION-SCREEN ON RADIOBUTTON GROUP gr`: Called when the values for a radio button group were passed `AT SELECTION-SCREEN ON EXIT-COMMAND`: Called by Back, Exit, or Cancel (e.g. used for cleanup tasks) `AT SELECTION-SCREEN ON HELP-REQUEST \| VALUE-REQUEST`: Relates to field (F1) and input (F4) help `AT SELECTION-SCREEN.`: Called as last event in the selection screen processing when all input values are passed to the program	PROGRAM. TYPES: BEGIN OF st, id TYPE c LENGTH 3, event_block TYPE c LENGTH 50, time TYPE utclong, END OF st. DATA log TYPE TABLE OF st WITH EMPTY KEY. DATA counter TYPE i. SELECTION-SCREEN BEGIN OF LINE. SELECTION-SCREEN COMMENT (10) txt1. PARAMETERS text1 TYPE c LENGTH 10 LOWER CASE. SELECTION-SCREEN END OF LINE. SELECTION-SCREEN BEGIN OF BLOCK blk. PARAMETERS text2 TYPE c LENGTH 10 LOWER CASE. PARAMETERS text3 TYPE c LENGTH 10 LOWER CASE. SELECTION-SCREEN END OF BLOCK blk. PARAMETERS: rb1 RADIOBUTTON GROUP grp DEFAULT 'X', rb2 RADIOBUTTON GROUP grp. LOAD-OF-PROGRAM. counter += 1. APPEND VALUE #( id = counter event_block = `LOAD-OF-PROGRAM` time = utclong_current( ) ) TO log. INITIALIZATION. counter += 1. APPEND VALUE #( id = counter event_block = `INITIALIZATION` time = utclong_current( ) ) TO log. text1 = 'Hello'. text2 = 'World'. text3 = 'ABAP'. txt1 = 'Text 1'. AT SELECTION-SCREEN OUTPUT. counter += 1. APPEND VALUE #( id = counter event_block = `AT SELECTION-SCREEN OUTPUT` time = utclong_current( ) ) TO log. LOOP AT SCREEN INTO DATA(wa). IF wa-name = 'TEXT1'. wa-intensified = '1'. MODIFY SCREEN FROM wa. ENDIF. ENDLOOP. AT SELECTION-SCREEN ON text1. counter += 1. APPEND VALUE #( id = counter event_block = `AT SELECTION-SCREEN ON` time = utclong_current( ) ) TO log. AT SELECTION-SCREEN ON BLOCK blk. counter += 1. APPEND VALUE #( id = counter event_block = `AT SELECTION-SCREEN ON BLOCK` time = utclong_current( ) ) TO log. AT SELECTION-SCREEN ON RADIOBUTTON GROUP grp. counter += 1. APPEND VALUE #( id = counter event_block = `AT SELECTION-SCREEN ON RADIOBUTTON GROUP` time = utclong_current( ) ) TO log. AT SELECTION-SCREEN ON EXIT-COMMAND. counter += 1. APPEND VALUE #( id = counter event_block = `AT SELECTION-SCREEN ON EXIT-COMMAND` time = utclong_current( ) ) TO log. DATA msg TYPE string VALUE `These events have already been raised:`. LOOP AT log INTO DATA(cmd). msg &&= \| { cmd-event_block }\|. ENDLOOP. MESSAGE msg TYPE 'I'. AT SELECTION-SCREEN. APPEND VALUE #( id = counter event_block = `AT SELECTION-SCREEN` time = utclong_current( ) ) TO log. START-OF-SELECTION. counter += 1. APPEND VALUE #( id = counter event_block = `START-OF-SELECTION` time = utclong_current( ) ) TO log. LOOP AT log INTO DATA(wa). WRITE: /(*) wa-id, (45) wa-event_block, (30) wa-time. ENDLOOP.
List events	Are triggered during the list creation and after certain user actions on a displayed list. During list creation: `TOP-OF-PAGE` For definining page headers; called when a basic list is created and when a new page begins (`... DURING LINE-SELECTION` is called when details lists are created) `END-OF-PAGE` For definining page footers; called when the end of a page is reached, for example, when the specified number of lines in the `LINE-COUNT` addition (e.g. `PROGRAM LINE-COUNT 20(3).`) has been reached After user actions: `AT LINE-SELECTION` Called when a screen list is displayed, the screen cursor is on a list line and a function is selected using the function code `PICK`; when specified, the function key F2 is enabled and, therefore, double click functionality; F2 and a double click are linked with the function code `PICK`. `AT USER-COMMAND` Called when a function with a user-defined function code is selected when a screen list is displayed; the function codes can be evaluated using `sy-ucomm`; you can set a list event programmatically using `SET USER-COMMAND`.	The following example is an excerpt of the executable example contained in the repository. Find more information in the comments there. The example is just intended to explore and visualize various list events. PROGRAM LINE-COUNT 20(3). TYPES: BEGIN OF st, id TYPE c LENGTH 3, event_block TYPE c LENGTH 50, time TYPE utclong, END OF st. DATA: counter_line TYPE i, reporting_and_selscr_log TYPE TABLE OF st WITH EMPTY KEY, list_log TYPE TABLE OF st WITH EMPTY KEY, counter TYPE i, tstmp TYPE utclong. SELECTION-SCREEN COMMENT /1(70) intro. SELECTION-SCREEN SKIP. PARAMETERS: text TYPE c length 10. SELECTION-SCREEN SKIP 2. SELECTION-SCREEN COMMENT /1(70) note. CLASS demo DEFINITION. PUBLIC SECTION. CLASS-METHODS: sel_screen_evt IMPORTING evt TYPE string, write_line IMPORTING evt TYPE string utc TYPE utclong, counter, list_evt IMPORTING evt TYPE string, write_rep_sel_log, write_list_log. CLASS-DATA: li_wa LIKE LINE OF list_log, sel_wa LIKE LINE OF reporting_and_selscr_log. ENDCLASS. CLASS demo IMPLEMENTATION. METHOD counter. IF counter = 0. counter = 1. ELSE. counter += 1. ENDIF. ENDMETHOD. METHOD sel_screen_evt. counter( ). APPEND VALUE #( id = counter event_block = evt time = utclong_current( ) ) TO reporting_and_selscr_log. ENDMETHOD. METHOD list_evt. counter( ). APPEND VALUE #( id = counter event_block = evt time = utclong_current( ) ) TO list_log. ENDMETHOD. METHOD write_line. counter( ). WRITE: /3() counter, 15 evt, 60 utc. ENDMETHOD. METHOD write_rep_sel_log. SKIP. WRITE / '******* Log entries for reporting and selection screen events ******' COLOR 2. FORMAT COLOR 2. WRITE: /3 'ID', 15 'Event Block', 60 'Time' . FORMAT COLOR OFF. LOOP AT reporting_and_selscr_log INTO sel_wa. WRITE: / sel_wa-id UNDER 'ID', sel_wa-event_block UNDER 'Event Block', sel_wa-time UNDER 'Time'. ENDLOOP. ENDMETHOD. METHOD write_list_log. WRITE / '****** Log entries for list events ******' COLOR 2. FORMAT COLOR 2. WRITE: /3 'ID', 15 'Event Block', 60 'Time' . FORMAT COLOR OFF. LOOP AT list_log INTO li_wa. WRITE: / li_wa-id UNDER 'ID', li_wa-event_block UNDER 'Event Block', li_wa-time UNDER 'Time'. ENDLOOP. ENDMETHOD. ENDCLASS. ****************************************************************** LOAD-OF-PROGRAM. demo=>sel_screen_evt( `LOAD-OF-PROGRAM` ). ****************************************************************** INITIALIZATION. demo=>sel_screen_evt( `INITIALIZATION` ). intro = 'Exploring list events'. note = 'The Back/Exit/Cancel buttons raise the ON EXIT-COMMAND event.'. text = 'Hello'. ****************************************************************** START-OF-SELECTION. SET USER-COMMAND 'START'. demo=>sel_screen_evt( `START-OF-SELECTION` ). WRITE / 'This is the basic list showing the content of a log table (mostly reporting and selection screen events). Double-click a line in this list to display more events in a details list.' COLOR 4. SKIP. WRITE / \|Parameter value: "{ text }"\| COLOR 2. IF reporting_and_selscr_log IS NOT INITIAL. demo=>write_rep_sel_log( ). ENDIF. ****************************************************************** AT LINE-SELECTION. demo=>list_evt( evt = `AT LINE-SELECTION` ). SET USER-COMMAND 'LINE'. IF sy-lsind <= 1. WRITE / 'This is a details list. It shows the content of another log table (mostly list events). Clicking in this list does nothing meaningful.' COLOR 4. WRITE / 'You may want to go back to the basic list, double-click a line there to come back here, and see more log entries added for list events.' COLOR 4. WRITE / 'When the counter reaches 40, the program is restarted :)' COLOR 4. SKIP. WRITE / `********** Some sy Components **********` COLOR 2. WRITE / \|Content of clicked line (sy-lisel): "{ sy-lisel }"\|. WRITE / \|Number of clicked line (sy-lilli): "{ sy-lilli }"\|. WRITE / \|List level of the current list (sy-lsind): "{ sy-lsind }"\|. SKIP. IF list_log IS NOT INITIAL. demo=>write_list_log( ). ENDIF. ENDIF. ****************************************************************** AT USER-COMMAND. CASE sy-ucomm. WHEN 'START'. demo=>list_evt( `AT USER-COMMAND (Function code: START)` ). MESSAGE \|AT USER-COMMAND event raised (Function code: START). Counter value: { counter }.\| TYPE 'I'. WHEN 'LINE'. demo=>list_evt( `AT USER-COMMAND (Function code: LINE)` ). MESSAGE \|AT USER-COMMAND event raised (Function code: LINE). Counter value: { counter }.\| TYPE 'I'. IF counter >= 40. MESSAGE \|The counter has reached the threshold. The program will be started again using a SUBMIT statement.\| TYPE 'I'. SUBMIT (sy-repid) VIA SELECTION-SCREEN. ENDIF. ENDCASE. ****************************************************************** TOP-OF-PAGE. tstmp = utclong_current( ). demo=>counter( ). APPEND VALUE #( id = counter event_block = \|TOP-OF-PAGE\| time = tstmp ) TO list_log. WRITE: / \|***************** Title inserted at TOP-OF-PAGE event ({ counter }) *****************\|. ****************************************************************** TOP-OF-PAGE DURING LINE-SELECTION. tstmp = utclong_current( ). demo=>counter( ). APPEND VALUE #( id = counter event_block = \|TOP-OF-PAGE DURING LINE-SELECTION\| time = tstmp ) TO list_log. WRITE: / \|***************** Title inserted at TOP-OF-PAGE DURING LINE-SELECTION event ({ counter }) *****************\|. ****************************************************************** END-OF-PAGE. tstmp = utclong_current( ). demo=>counter( ). APPEND VALUE #( id = counter event_block = \|END-OF-PAGE\| time = tstmp ) TO list_log. WRITE: / \|***************** Footer inserted at END-OF-PAGE event ({ counter }) *******************\|.

Selection Screens and Classic Lists

Introduction

Selection Screens

Classic Lists

ABAP Statements for Selection Screens

PARAMETERS

SELECT-OPTIONS

SELECTION-SCREEN

Creating Selection Screens

Adapting the Selection Screen Layout

Using Elements from Other Selection Screens

Calling Selection Screens

Excursion: SUBMIT Statements

ABAP Statements for Classic Lists

Creating Lists with WRITE Statements

Formatting Output Using FORMAT Statements

List Creation-Related ABAP Keywords and Additions

Processing Lists in List Buffers

Event Blocks

Excursion: SAP List Viewer (ALV)

Getting Started

Optional Layout Settings and Functionality

More Information

Executable Examples