Docs: recommend follow_up_action, mark action->gen obsolete

claude · claude · commit 3f642af4f139 · 2026-07-15T23:14:09.000Z
Reverse the previous obsolete designation: follow_up_action is now documented as the recommended way to trigger a frontend action from the backend, and action->gen is marked obsolete. - follow_up_action.md rewritten as the recommended page; action.md rewritten as the obsolete page pointing to it - all cookbook code examples (browser interaction, device capabilities, model, odata, launchpad, ...) converted from action->gen( val/t_arg ) to the equivalent follow_up_action( |.eF('EVENT', args)| ) form - prose references in frontend.md, focus.md, size_limit.md, custom_controls.md and custom_js.md updated accordingly vitepress build passes (no dead links). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015vTnxZtHiAd4tiqMvxFdgJ
diff --git a/docs/configuration/launchpad.md b/docs/configuration/launchpad.md
@@ -34,9 +34,7 @@ ENDIF.
 Change the Launchpad shell title from ABAP at any time with the `set_title_launchpad` frontend event:
 
 ```abap
-client->action->gen(
-    val   = z2ui5_if_client=>cs_event-set_title_launchpad
-    t_arg = VALUE #( ( `My Dynamic Title` ) ) ).
+client->follow_up_action( |.eF('SET_TITLE_LAUNCHPAD', 'My Dynamic Title')| ).
 ```
 
 #### Read Startup Parameters
diff --git a/docs/cookbook/browser_interaction/clipboard.md b/docs/cookbook/browser_interaction/clipboard.md
@@ -31,9 +31,7 @@ CLASS z2ui5_cl_sample_clipboard IMPLEMENTATION.
             )->stringify( ) ).
 
       WHEN client->check_on_event( `COPY` ).
-        client->action->gen(
-            val   = client->cs_event-clipboard_copy
-            t_arg = VALUE #( ( mv_text ) ) ).
+        client->follow_up_action( |.eF('CLIPBOARD_COPY', '{ mv_text }')| ).
         client->message_toast_display( `copied` ).
 
     ENDCASE.
diff --git a/docs/cookbook/browser_interaction/focus.md b/docs/cookbook/browser_interaction/focus.md
@@ -25,7 +25,7 @@ This is useful for guided data entry, barcode scanning, or any flow where the ne
 
 #### Basic Usage
 
-After processing an event, call `client->action->gen( )` with `cs_event-set_focus` and the id of the input to focus next. (The value bindings on the inputs are omitted here to keep the focus logic clear — see [Barcode Scanning](/cookbook/device_capabilities/barcode_scanning) for the same form with bound inputs.)
+After processing an event, call `client->follow_up_action( )` with the `SET_FOCUS` frontend event and the id of the input to focus next. (The value bindings on the inputs are omitted here to keep the focus logic clear — see [Barcode Scanning](/cookbook/device_capabilities/barcode_scanning) for the same form with bound inputs.)
 
 ```abap
 METHOD z2ui5_if_app~main.
@@ -45,12 +45,10 @@ METHOD z2ui5_if_app~main.
       client->view_display( page->stringify( ) ).
 
     ELSEIF client->check_on_event( `ONE_ENTER` ).
-        client->action->gen( val   = client->cs_event-set_focus
-                        t_arg = VALUE #( ( `id2` ) ) ).
+        client->follow_up_action( |.eF('SET_FOCUS', 'id2')| ).
 
     ELSEIF client->check_on_event( `TWO_ENTER` ).
-        client->action->gen( val   = client->cs_event-set_focus
-                        t_arg = VALUE #( ( `id1` ) ) ).
+        client->follow_up_action( |.eF('SET_FOCUS', 'id1')| ).
 
     ENDIF.
 
@@ -64,8 +62,7 @@ After the user presses Enter in `id1`, the backend fires `set_focus` for `id2` a
 To position the caret inside the field or pre-select a range, pass the start and end offsets as additional arguments:
 
 ```abap
-client->action->gen( val   = client->cs_event-set_focus
-                t_arg = VALUE #( ( `id1` ) ( `0` ) ( `5` ) ) ).
+client->follow_up_action( |.eF('SET_FOCUS', 'id1', '0', '5')| ).
 ```
 
 #### Barcode Scanning
diff --git a/docs/cookbook/browser_interaction/scrolling.md b/docs/cookbook/browser_interaction/scrolling.md
@@ -52,11 +52,9 @@ CLASS z2ui5_cl_sample_scrolling IMPLEMENTATION.
 
     CASE client->get( )-event.
       WHEN `SCROLL_TOP`.
-        client->action->gen( val   = client->cs_event-scroll_to
-                        t_arg = VALUE #( ( `id_page` ) ( `0` ) ) ).
+        client->follow_up_action( |.eF('SCROLL_TO', 'id_page', '0')| ).
       WHEN `SCROLL_BOTTOM`.
-        client->action->gen( val   = client->cs_event-scroll_to
-                        t_arg = VALUE #( ( `id_page` ) ( `99999` ) ) ).
+        client->follow_up_action( |.eF('SCROLL_TO', 'id_page', '99999')| ).
     ENDCASE.
 
   ENDMETHOD.
@@ -66,22 +64,19 @@ ENDCLASS.
 The arguments for `scroll_to` are `id`, `scrollTop` (y, px), `scrollLeft` (x, px, optional), and `behavior` (optional):
 
 ```abap
-client->action->gen( val   = client->cs_event-scroll_to
-                t_arg = VALUE #( ( `id_page` ) ( `500` ) ( `0` ) ( `smooth` ) ) ).
+client->follow_up_action( |.eF('SCROLL_TO', 'id_page', '500', '0', 'smooth')| ).
 ```
 
 #### Scroll an Element into View
 
 To reveal a specific control — e.g. a row after a search — use `scroll_into_view` with the target control's id:
 
 ```abap
-client->action->gen( val   = client->cs_event-scroll_into_view
-                t_arg = VALUE #( ( `id_row_42` ) ) ).
+client->follow_up_action( |.eF('SCROLL_INTO_VIEW', 'id_row_42')| ).
 ```
 
 Additional optional arguments mirror the browser's `scrollIntoView` options: `behavior` (`smooth` | `auto` | `instant`), `block` (`start` | `center` | `end` | `nearest`), `inline` (`nearest` | `start` | `center` | `end`):
 
 ```abap
-client->action->gen( val   = client->cs_event-scroll_into_view
-                t_arg = VALUE #( ( `id_row_42` ) ( `smooth` ) ( `center` ) ) ).
+client->follow_up_action( |.eF('SCROLL_INTO_VIEW', 'id_row_42', 'smooth', 'center')| ).
 ```
diff --git a/docs/cookbook/browser_interaction/soft_keyboard.md b/docs/cookbook/browser_interaction/soft_keyboard.md
@@ -36,8 +36,7 @@ METHOD z2ui5_if_app~main.
 
     CASE client->get( )-event.
       WHEN `CALL_KEYBOARD`.
-        client->action->gen( val   = client->cs_event-keyboard_set_mode
-                        t_arg = VALUE #( ( `ZINPUT` ) ( `none` ) ) ).
+        client->follow_up_action( |.eF('KEYBOARD_SET_MODE', 'ZINPUT', 'none')| ).
       WHEN `BACK`.
         client->nav_app_leave( ).
     ENDCASE.
diff --git a/docs/cookbook/browser_interaction/timer.md b/docs/cookbook/browser_interaction/timer.md
@@ -8,9 +8,7 @@ Fire a backend event after a delay with the `start_timer` frontend event. Handy
 Pass the event name to fire and the delay in milliseconds:
 
 ```abap
-client->action->gen(
-    val   = client->cs_event-start_timer
-    t_arg = VALUE #( ( `REFRESH` ) ( `2000` ) ) ).
+client->follow_up_action( |.eF('START_TIMER', 'REFRESH', '2000')| ).
 ```
 
 After 2 seconds the browser triggers a backend roundtrip with the event name `REFRESH`, which you handle via `check_on_event` like any other event.
@@ -38,14 +36,12 @@ CLASS z2ui5_cl_sample_timer IMPLEMENTATION.
             )->page( `abap2UI5 - Timer`
                 )->text( client->_bind( counter )
             )->stringify( ) ).
-        client->action->gen( val   = client->cs_event-start_timer
-                        t_arg = VALUE #( ( `TICK` ) ( `2000` ) ) ).
+        client->follow_up_action( |.eF('START_TIMER', 'TICK', '2000')| ).
 
       WHEN client->check_on_event( `TICK` ).
         counter = counter + 1.
         client->view_model_update( ).
-        client->action->gen( val   = client->cs_event-start_timer
-                        t_arg = VALUE #( ( `TICK` ) ( `2000` ) ) ).
+        client->follow_up_action( |.eF('START_TIMER', 'TICK', '2000')| ).
 
     ENDCASE.
 
@@ -61,12 +57,10 @@ A single `start_timer` call fires once — perfect for a deferred action like op
 
 ```abap
 WHEN client->check_on_event( `BUTTON_OPEN_NEW_TAB` ).
-  client->action->gen( val   = client->cs_event-start_timer
-                  t_arg = VALUE #( ( `FIRE_OPEN_TAB` ) ( `500` ) ) ).
+  client->follow_up_action( |.eF('START_TIMER', 'FIRE_OPEN_TAB', '500')| ).
 
 WHEN client->check_on_event( `FIRE_OPEN_TAB` ).
-  client->action->gen( val   = client->cs_event-open_new_tab
-                  t_arg = VALUE #( ( `https://www.google.com/search?q=abap2ui5` ) ) ).
+  client->follow_up_action( |.eF('OPEN_NEW_TAB', 'https://www.google.com/search?q=abap2ui5')| ).
 ```
 
 #### Replacing a Pending Timer
diff --git a/docs/cookbook/browser_interaction/title.md b/docs/cookbook/browser_interaction/title.md
@@ -23,9 +23,7 @@ METHOD z2ui5_if_app~main.
             )->stringify( ) ).
 
       WHEN client->check_on_event( `RENAME` ).
-        client->action->gen(
-            val   = client->cs_event-set_title
-            t_arg = VALUE #( ( `Invoice 4711` ) ) ).
+        client->follow_up_action( |.eF('SET_TITLE', 'Invoice 4711')| ).
 
     ENDCASE.
 
@@ -37,9 +35,7 @@ METHOD z2ui5_if_app~main.
 When the app runs inside an SAP Fiori Launchpad shell, use the dedicated `set_title_launchpad` event instead. It forwards the title to the shell's `ShellUIService` rather than setting `document.title`:
 
 ```abap
-client->action->gen(
-    val   = client->cs_event-set_title_launchpad
-    t_arg = VALUE #( ( `Invoice 4711` ) ) ).
+client->follow_up_action( |.eF('SET_TITLE_LAUNCHPAD', 'Invoice 4711')| ).
 ```
 
 Use `set_title` for the browser tab/window title (standalone) and `set_title_launchpad` for the launchpad shell title.
diff --git a/docs/cookbook/browser_interaction/url_handling.md b/docs/cookbook/browser_interaction/url_handling.md
@@ -16,9 +16,7 @@ DATA(lv_search) = client->get( )-s_config-search.
 Open a URL in a new browser tab via a frontend event:
 ```abap
 DATA(lv_url) = `https://www.abap2UI5.org`.
-client->action->gen(
-    val   = client->cs_event-open_new_tab
-    t_arg = VALUE #( ( lv_url ) ) ).
+client->follow_up_action( |.eF('OPEN_NEW_TAB', '{ lv_url }')| ).
 ```
 
 #### Browser History
diff --git a/docs/cookbook/device_capabilities/audio.md b/docs/cookbook/device_capabilities/audio.md
@@ -39,8 +39,7 @@ CLASS z2ui5_cl_sample_sound IMPLEMENTATION.
 
     IF client->get( )-event = `CHECK_INPUT`.
       IF company_code IS INITIAL.
-        client->action->gen( val   = client->cs_event-play_audio
-                        t_arg = VALUE #( ( `/SAP/PUBLIC/BC/ABAP/mime_demo/bam.wav` ) ) ).
+        client->follow_up_action( |.eF('PLAY_AUDIO', '/SAP/PUBLIC/BC/ABAP/mime_demo/bam.wav')| ).
         client->message_box_display( type = `error` text = `Input is empty!` ).
       ELSE.
         CLEAR company_code.
diff --git a/docs/cookbook/device_capabilities/barcode_scanning.md b/docs/cookbook/device_capabilities/barcode_scanning.md
@@ -86,11 +86,9 @@ CLASS z2ui5_cl_sample_focus IMPLEMENTATION.
 
     CASE client->get( )-event.
       WHEN `ONE_ENTER`.
-        client->action->gen( val   = client->cs_event-set_focus
-                        t_arg = VALUE #( ( `id2` ) ) ).
+        client->follow_up_action( |.eF('SET_FOCUS', 'id2')| ).
       WHEN `TWO_ENTER`.
-        client->action->gen( val   = client->cs_event-set_focus
-                        t_arg = VALUE #( ( `id1` ) ) ).
+        client->follow_up_action( |.eF('SET_FOCUS', 'id1')| ).
     ENDCASE.
 
   ENDMETHOD.
@@ -131,8 +129,7 @@ CLASS z2ui5_cl_sample_sound IMPLEMENTATION.
 
     IF client->get( )-event = `CHECK_INPUT`.
       IF company_code IS INITIAL.
-        client->action->gen( val   = client->cs_event-play_audio
-                        t_arg = VALUE #( ( `/SAP/PUBLIC/BC/ABAP/mime_demo/bam.wav` ) ) ).
+        client->follow_up_action( |.eF('PLAY_AUDIO', '/SAP/PUBLIC/BC/ABAP/mime_demo/bam.wav')| ).
         client->message_box_display( type = `error` text = `Input is empty!` ).
       ELSE.
         CLEAR company_code.
diff --git a/docs/cookbook/device_capabilities/pdf.md b/docs/cookbook/device_capabilities/pdf.md
@@ -41,10 +41,7 @@ ENDMETHOD.
 To let the user save the PDF rather than view it inline, use the [file download](./upload_download.md) pattern:
 
 ```abap
-client->action->gen(
-    val   = client->cs_event-download_b64_file
-    t_arg = VALUE #( ( `data:application/pdf;base64,` && lv_base64 )
-                     ( `invoice_4711.pdf` ) ) ).
+client->follow_up_action( |.eF('DOWNLOAD_B64_FILE', 'data:application/pdf;base64,{ lv_base64 }', 'invoice_4711.pdf')| ).
 ```
 
 ::: tip
diff --git a/docs/cookbook/device_capabilities/spreadsheet.md b/docs/cookbook/device_capabilities/spreadsheet.md
@@ -118,9 +118,7 @@ Convert an internal table to an XLSX file and download it to the frontend:
         ( count = `3` value = `red` descr = `this is a description` ) ).
 
         DATA(lv_file) = lcl_help=>xlsx_get_by_itab( lt_tab ).
-        client->action->gen(
-            val   = client->cs_event-download_b64_file
-            t_arg = VALUE #( ( lv_file ) ( `test.xlsx` ) ) ).
+        client->follow_up_action( |.eF('DOWNLOAD_B64_FILE', '{ lv_file }', 'test.xlsx')| ).
     ENDIF.
 
 ENDMETHOD.
@@ -220,9 +218,7 @@ Instead of the XLSX API above (which can change between releases), consider the
       ( count = `3` value = `red` descr = `this is a description` ) ).
 
     DATA(lv_file) = lcl_help=>xlsx_get_by_itab( lt_tab ).
-    client->action->gen(
-      val   = client->cs_event-download_b64_file
-      t_arg = VALUE #( ( lv_file ) ( `test.xlsx` ) ) ).
+    client->follow_up_action( |.eF('DOWNLOAD_B64_FILE', '{ lv_file }', 'test.xlsx')| ).
   ENDIF.
 
 ENDMETHOD.
diff --git a/docs/cookbook/device_capabilities/upload_download.md b/docs/cookbook/device_capabilities/upload_download.md
@@ -66,9 +66,7 @@ See also `Z2UI5_CL_DEMO_APP_186`:
         `/zMDz8usXC3ddaHBj1GHj/As08fwTS7Kt1HBTmyN29vdwAw+/wbwLVOJ3uAD1wi/dUH7Qei66PfyuRj4Ik9is+hglfbkbfR3cnZm7chlUWLdwmprtCohX4HUtlOcQj` &&
         `LYCu+fzGJH2QRKvP3UNz8bWk1qMxjGTOMThZ3kvgLI5AzFfo379UAAAAASUVORK5CYII=`.
 
-        client->action->gen(
-            val   = client->cs_event-download_b64_file
-            t_arg = VALUE #( ( lv_content ) ( lv_name ) ) ).
+        client->follow_up_action( |.eF('DOWNLOAD_B64_FILE', '{ lv_content }', '{ lv_name }')| ).
     ENDCASE.
 
 ENDMETHOD.
diff --git a/docs/cookbook/event_navigation/action.md b/docs/cookbook/event_navigation/action.md
@@ -1,18 +1,35 @@
 ---
 outline: [2, 4]
 ---
-# Action
+# Action (Obsolete)
+
+::: warning Do Not Use Anymore
+`client->action->gen( )` is obsolete. Use
+[`client->follow_up_action( )`](/cookbook/expert_more/follow_up_action) instead.
+It schedules the same frontend event, called from the backend.
+:::
+
+## What Changed
+
+`action->gen( )` used to schedule a frontend event by name with typed arguments:
 
-Sometimes, once your backend event handler has finished, you want to trigger an action that runs on the frontend. The `action->gen` method schedules such a frontend event — it is executed in the browser after the response arrives:
 ```abap
-METHOD z2ui5_if_app~main.
+" obsolete — do not use
+client->action->gen(
+    val   = client->cs_event-open_new_tab
+    t_arg = VALUE #( ( `https://github.com/abap2UI5` ) ) ).
+```
 
-    client->action->gen(
-        val   = client->cs_event-open_new_tab
-        t_arg = VALUE #( ( `https://github.com/abap2UI5` ) ) ).
+The replacement passes the same frontend event as a `follow_up_action` string.
+`.eF('<EVENT>'<, args>)` calls the event; each argument is a quoted string:
 
-ENDMETHOD.
+```abap
+client->follow_up_action( |.eF('OPEN_NEW_TAB', 'https://github.com/abap2UI5')| ).
 ```
-`val` is one of the frontend events from `z2ui5_if_client=>cs_event` (see [Frontend](./frontend.md)); `t_arg` carries the arguments the event expects.
+
+`val` was one of the frontend events from `z2ui5_if_client=>cs_event` (see
+[Frontend](./frontend.md)) — the event id is simply its upper-case name
+(`cs_event-open_new_tab` → `OPEN_NEW_TAB`). `t_arg` carried the arguments the
+event expects; they now follow the event name in the `.eF( )` call.
 
 See sample `Z2UI5_CL_DEMO_APP_180` for a complete example.
diff --git a/docs/cookbook/event_navigation/frontend.md b/docs/cookbook/event_navigation/frontend.md
@@ -8,7 +8,7 @@ If you don't want to handle the event in the backend, fire actions directly on t
 - **`client->_event( )`** — causes a backend roundtrip; the event runs in the `main` method
 - **`client->_event_client( )`** — runs an action directly in the browser; no backend call
 
-Use `_event_client` on a UI5 control property (like `press`) when the response should happen entirely in the browser. To fire a frontend event **after** backend processing has finished, use [`client->action->gen`](./action.md) instead — it schedules the same frontend event but is called from the backend.
+Use `_event_client` on a UI5 control property (like `press`) when the response should happen entirely in the browser. To fire a frontend event **after** backend processing has finished, use [`client->follow_up_action`](/cookbook/expert_more/follow_up_action) instead — it schedules the same frontend event but is called from the backend.
 
 The following frontend events are available:
 ```abap
diff --git a/docs/cookbook/expert_more/app_state_share.md b/docs/cookbook/expert_more/app_state_share.md
@@ -74,7 +74,7 @@ CLASS z2ui5_cl_sample_share IMPLEMENTATION.
 
       WHEN client->check_on_event( `BUTTON_POST` ).
 
-        client->action->gen( z2ui5_if_client=>cs_event-clipboard_app_state ).
+        client->follow_up_action( |.eF('CLIPBOARD_APP_STATE')| ).
         client->message_toast_display( `clipboard copied` ).
 
     ENDCASE.
diff --git a/docs/cookbook/expert_more/custom_controls.md b/docs/cookbook/expert_more/custom_controls.md
@@ -4,7 +4,7 @@ outline: [2, 4]
 # Custom Controls (Obsolete)
 
 ::: warning Mostly Not Needed Anymore
-Earlier versions of abap2UI5 required custom UI5 controls to cover common browser interactions — setting the page title, moving focus, scrolling, copying to the clipboard, opening new tabs, and so on. These are now built into the framework as **frontend events**, callable from ABAP via `client->action->gen( client->cs_event-... )`. The custom controls that used to wrap these behaviors are obsolete.
+Earlier versions of abap2UI5 required custom UI5 controls to cover common browser interactions — setting the page title, moving focus, scrolling, copying to the clipboard, opening new tabs, and so on. These are now built into the framework as **frontend events**, callable from ABAP via `client->follow_up_action( )`. The custom controls that used to wrap these behaviors are obsolete.
 
 :::
 
@@ -28,8 +28,7 @@ The table below lists custom controls that are no longer necessary and the built
 Instead of writing a custom control, call the matching action after an event:
 
 ```abap
-client->action->gen( val   = client->cs_event-set_title
-                t_arg = VALUE #( ( `Invoice 4711` ) ) ).
+client->follow_up_action( |.eF('SET_TITLE', 'Invoice 4711')| ).
 ```
 
 See the linked cookbook pages above for the full argument list of each action.
diff --git a/docs/cookbook/expert_more/custom_js.md b/docs/cookbook/expert_more/custom_js.md
@@ -30,7 +30,7 @@ Before reaching for Custom JS, consider:
 
 If you accept the risks and decide to use it anyway, the idea is: send the JavaScript function with the view to the frontend, then call it later when an event fires.
 
-The `_generic` method creates a custom XML/HTML element — here an HTML `<script>` tag (namespace `html`). The `_cc_plain_xml` method inserts raw content into that element — in this case, the JavaScript function definition. On the backend, `client->follow_up_action` then runs the function by name on the frontend. (Note: `follow_up_action` is [obsolete](/cookbook/expert_more/follow_up_action) — custom JS is the one case its replacement `action->gen` deliberately does not cover, which is another reason to avoid this feature.)
+The `_generic` method creates a custom XML/HTML element — here an HTML `<script>` tag (namespace `html`). The `_cc_plain_xml` method inserts raw content into that element — in this case, the JavaScript function definition. On the backend, [`client->follow_up_action`](/cookbook/expert_more/follow_up_action) then runs the function by name on the frontend. Running arbitrary hand-written JavaScript like this is exactly the pattern this page warns against — for built-in browser interactions, call a named frontend event instead of injecting your own script.
 
 ```abap
   METHOD z2ui5_if_app~main.
@@ -80,6 +80,6 @@ If you want to look at — or hand-craft — the raw XML view that abap2UI5 prod
 </mvc:View>
 ```
 
-The browser parses the `html:script` element and executes its content as JavaScript at view render time. The function becomes available globally and can then be triggered from the backend via the obsolete [`follow_up_action`](/cookbook/expert_more/follow_up_action) — or, ideally, replaced entirely with a built-in `client->action->gen( )` call.
+The browser parses the `html:script` element and executes its content as JavaScript at view render time. The function becomes available globally and can then be triggered from the backend via [`follow_up_action`](/cookbook/expert_more/follow_up_action) — or, ideally, replaced entirely with a built-in frontend event (e.g. `SET_TITLE`, `SCROLL_TO`) instead of hand-written JavaScript.
 
 This is exactly what the `_generic` + `_cc_plain_xml` helpers shown above produce; the two approaches are equivalent. Both ship raw JavaScript from the backend to the browser, and both carry the security risks described above. Use neither unless there is genuinely no alternative.
diff --git a/docs/cookbook/expert_more/follow_up_action.md b/docs/cookbook/expert_more/follow_up_action.md
diff --git a/docs/cookbook/expert_more/odata.md b/docs/cookbook/expert_more/odata.md
diff --git a/docs/cookbook/model/size_limit.md b/docs/cookbook/model/size_limit.md
