Refactor code style: naming conventions and string literals

CLAUDE.md

@@ -32,12 +32,16 @@ All serialized files (`.abap`, `.xml`, and any other abapGit-managed file types)
 - Follow the [SAP ABAP Style Guide](https://github.com/SAP/styleguides/blob/main/clean-abap/CleanABAP.md).
 - Never use an init flag attribute (`check_initialized`, `mv_init`, `is_initialized`, etc.). Always use `client->check_on_init( )` instead.
 - Use backticks for all string literals, not single quotes.
+- Use string templates (`|...|` with `{ }` for embedded expressions) instead of `&&` for string concatenation (e.g. `|item { name }|` not `` `item ` && name ``).
 - Prefer functional to procedural language constructs — use `var = VALUE #( ).` to reset a variable, never `CLEAR var.`.
-- Do not use Hungarian notation — no type prefixes on variable or attribute names (e.g. `product` not `lv_product`, `client` not `mo_client`).
+- Use type prefixes only for tables and structures: prefix table variables/attributes with `t_` (e.g. `t_items`) and structure variables/attributes with `s_` (e.g. `s_screen`). Do not add prefixes to scalar variables or object references.
+- Name local types with a `ty_s_` prefix for structure types (e.g. `ty_s_row`) and `ty_t_` for table types (e.g. `ty_t_rows`). Only define a `ty_t_` table type when it is used more than once — for a single-use table, declare it inline with `STANDARD TABLE OF ty_s_xxx`.
+- No blank line between a `TYPES` definition and the `DATA` declaration that directly uses it.
 - Class names are always written in **lowercase** in both `DEFINITION` and `IMPLEMENTATION` — never uppercase.
 - Classes are **not** `FINAL` — do not add the `FINAL` keyword to class definitions.
 - Use `DEFINITION PUBLIC.` — never `DEFINITION PUBLIC CREATE PUBLIC.` (`CREATE PUBLIC` is the default and adds unnecessary overhead).
 - Always include `PROTECTED SECTION.` and `PRIVATE SECTION.` in the class definition, even if empty.
+- In every section (`PUBLIC SECTION.`, `PROTECTED SECTION.`), always follow this declaration order: `TYPES` first, then `DATA`, then `METHODS`.
 - **Blank lines — class definition** (`EMPTY_LINES_IN_CLASS_DEFINITION`):
   - Add one blank line above each section keyword (`PUBLIC SECTION.`, `PROTECTED SECTION.`, `PRIVATE SECTION.`) — unless the preceding section is empty.
   - No blank line directly below a section keyword.
@@ -138,9 +142,11 @@ Always use `client->_event_nav_app_leave()` to bind the back button event direct
 METHOD view_display.
 
   DATA(view) = z2ui5_cl_xml_view=>factory( ).
-  DATA(page) = view->page( title = `My App`
-                            shownavbutton = client->check_app_prev_stack( )
-                            navbuttonpress = client->_event_nav_app_leave( ) ).
+  DATA(page) = view->shell(
+      )->page(
+          title          = `My App`
+          shownavbutton  = client->check_app_prev_stack( )
+          navbuttonpress = client->_event_nav_app_leave( ) ).
   " ...
   client->view_display( view->stringify( ) ).
 
@@ -155,7 +161,7 @@ METHOD on_event.
   CASE client->get( )-event.
     WHEN `BACK`.
       " interact with previous app instance first
-      CAST z2ui5_cl_app_parent( client->get_app_prev( ) )->set_result( ms_result ).
+      CAST z2ui5_cl_app_parent( client->get_app_prev( ) )->set_result( s_result ).
       client->nav_app_leave( ).
   ENDCASE.
 
@@ -268,6 +274,8 @@ Write everything directly in `main` — no method encapsulation needed. Count on
 
 ### Larger apps — canonical template
 
+When the logic no longer fits inside `main`, always extract exactly `on_init` and `on_event` as the first step — never use other method names for this purpose. `main` then becomes a pure dispatcher that calls these two methods. Only add further methods (`view_display`, `data_read`, etc.) when they are actually needed.
+
 The following is the **maximum structure**. Only add methods that are actually needed.
 
 ### Event handler sub-methods
@@ -281,6 +289,7 @@ CLASS z2ui5_cl_app_xxx DEFINITION PUBLIC.
     " bound data (DATA attributes for _bind/_bind_edit)...
   PROTECTED SECTION.
     DATA client TYPE REF TO z2ui5_if_client.
+
     METHODS on_init.        " first call: load data, display view
     METHODS on_event.       " user triggered an event
     METHODS on_navigation.  " returned from sub-app or popup

src/z2ui5_cl_demo_app_002.clas.abap

@@ -15,7 +15,7 @@ CLASS z2ui5_cl_demo_app_002 DEFINITION PUBLIC.
       END OF combobox_item.
 
     DATA:
-      BEGIN OF screen,
+      BEGIN OF s_screen,
         check_is_active TYPE abap_bool,
         colour          TYPE string,
         combo_key       TYPE string,
@@ -27,10 +27,10 @@ CLASS z2ui5_cl_demo_app_002 DEFINITION PUBLIC.
         time_end        TYPE string,
         check_switch_01 TYPE abap_bool VALUE abap_false,
         check_switch_02 TYPE abap_bool VALUE abap_false,
-      END OF screen.
+      END OF s_screen.
 
-    DATA suggestions TYPE STANDARD TABLE OF suggestion_item WITH EMPTY KEY.
-    DATA combo       TYPE STANDARD TABLE OF combobox_item WITH EMPTY KEY.
+    DATA t_suggestions TYPE STANDARD TABLE OF suggestion_item WITH EMPTY KEY.
+    DATA t_combo       TYPE STANDARD TABLE OF combobox_item WITH EMPTY KEY.
 
   PROTECTED SECTION.
     DATA client TYPE REF TO z2ui5_if_client.
@@ -59,7 +59,7 @@ CLASS z2ui5_cl_demo_app_002 IMPLEMENTATION.
 
   METHOD on_init.
 
-    screen = VALUE #(
+    s_screen = VALUE #(
         check_is_active = abap_true
         colour          = `BLUE`
         combo_key       = `GRAY`
@@ -69,15 +69,15 @@ CLASS z2ui5_cl_demo_app_002 IMPLEMENTATION.
         time_start      = `05:24:00`
         time_end        = `17:23:57` ).
 
-    suggestions = VALUE #(
+    t_suggestions = VALUE #(
         ( descr = `Green`  value = `GREEN` )
         ( descr = `Blue`   value = `BLUE` )
         ( descr = `Black`  value = `BLACK` )
         ( descr = `Gray`   value = `GRAY` )
         ( descr = `Blue2`  value = `BLUE2` )
         ( descr = `Blue3`  value = `BLUE3` ) ).
 
-    combo = VALUE #(
+    t_combo = VALUE #(
         ( key = `BLUE`  text = `green` )
         ( key = `GREEN` text = `blue` )
         ( key = `BLACK` text = `red` )
@@ -94,7 +94,7 @@ CLASS z2ui5_cl_demo_app_002 IMPLEMENTATION.
       WHEN `BUTTON_SEND`.
         client->message_box_display( `success - values send to the server` ).
       WHEN `BUTTON_CLEAR`.
-        screen = VALUE #( ).
+        s_screen = VALUE #( ).
         client->message_toast_display( `View initialized` ).
     ENDCASE.
 
@@ -120,9 +120,9 @@ CLASS z2ui5_cl_demo_app_002 IMPLEMENTATION.
         )->label( `Input with suggestion items`
         )->input(
             id              = `suggInput`
-            value           = client->_bind_edit( screen-colour )
+            value           = client->_bind_edit( s_screen-colour )
             placeholder     = `Fill in your favorite color`
-            suggestionitems = client->_bind( suggestions )
+            suggestionitems = client->_bind( t_suggestions )
             showsuggestion  = abap_true )->get(
         )->suggestion_items( )->get(
             )->list_item(
@@ -134,12 +134,12 @@ CLASS z2ui5_cl_demo_app_002 IMPLEMENTATION.
         editable = abap_true
         )->content( `form`
         )->label( `Date`
-        )->date_picker( client->_bind_edit( screen-date )
+        )->date_picker( client->_bind_edit( s_screen-date )
         )->label( `Date and Time`
-        )->date_time_picker( client->_bind_edit( screen-date_time )
+        )->date_time_picker( client->_bind_edit( s_screen-date_time )
         )->label( `Time Begin/End`
-        )->time_picker( client->_bind_edit( screen-time_start )
-        )->time_picker( client->_bind_edit( screen-time_end ) ).
+        )->time_picker( client->_bind_edit( s_screen-time_start )
+        )->time_picker( client->_bind_edit( s_screen-time_end ) ).
 
     DATA(content) = page->grid( `L12 M12 S12`
         )->content( `layout`
@@ -149,26 +149,26 @@ CLASS z2ui5_cl_demo_app_002 IMPLEMENTATION.
                 )->content( `form` ).
 
     content->label( `Checkbox` )->checkbox(
-        selected = client->_bind_edit( screen-check_is_active )
+        selected = client->_bind_edit( s_screen-check_is_active )
         text     = `this is a checkbox`
         enabled  = abap_true ).
 
     content->label( `Combobox` )->combobox(
-        selectedkey = client->_bind_edit( screen-combo_key )
-        items       = client->_bind( combo )
+        selectedkey = client->_bind_edit( s_screen-combo_key )
+        items       = client->_bind( t_combo )
         )->item(
             key  = `{KEY}`
             text = `{TEXT}` ).
 
     content->label( `Combobox2` )->combobox(
-        selectedkey = client->_bind_edit( screen-combo_key2 )
-        items       = client->_bind( combo )
+        selectedkey = client->_bind_edit( s_screen-combo_key2 )
+        items       = client->_bind( t_combo )
         )->item(
             key  = `{KEY}`
             text = `{TEXT}` ).
 
     content->label( `Segmented Button` )->segmented_button(
-        client->_bind_edit( screen-segment_key )
+        client->_bind_edit( s_screen-segment_key )
         )->items(
             )->segmented_button_item(
                 key  = `BLUE`
@@ -189,13 +189,13 @@ CLASS z2ui5_cl_demo_app_002 IMPLEMENTATION.
         customtextoff = `B` ).
 
     content->label( `Switch accept/reject` )->switch(
-        state         = client->_bind_edit( screen-check_switch_01 )
+        state         = client->_bind_edit( s_screen-check_switch_01 )
         customtexton  = `on`
         customtextoff = `off`
         type          = `AcceptReject` ).
 
     content->label( `Switch normal` )->switch(
-        state         = client->_bind_edit( screen-check_switch_02 )
+        state         = client->_bind_edit( s_screen-check_switch_02 )
         customtexton  = `YES`
         customtextoff = `NO` ).
 

src/z2ui5_cl_demo_app_003.clas.abap

@@ -1,73 +1,65 @@
 CLASS z2ui5_cl_demo_app_003 DEFINITION PUBLIC.
 
   PUBLIC SECTION.
-
     INTERFACES z2ui5_if_app.
 
     TYPES:
-      BEGIN OF ty_row,
+      BEGIN OF ty_s_row,
         title    TYPE string,
         value    TYPE string,
         descr    TYPE string,
         icon     TYPE string,
         info     TYPE string,
         selected TYPE abap_bool,
         checkbox TYPE abap_bool,
-      END OF ty_row.
-
-    DATA t_tab TYPE STANDARD TABLE OF ty_row WITH EMPTY KEY.
-
+      END OF ty_s_row.
+    DATA t_tab TYPE STANDARD TABLE OF ty_s_row WITH EMPTY KEY.
 
   PROTECTED SECTION.
   PRIVATE SECTION.
 ENDCLASS.
 
 
-
-CLASS Z2UI5_CL_DEMO_APP_003 IMPLEMENTATION.
-
+CLASS z2ui5_cl_demo_app_003 IMPLEMENTATION.
 
   METHOD z2ui5_if_app~main.
 
     IF client->check_on_init( ).
 
       t_tab = VALUE #(
-        ( title = 'row_01'  info = 'completed'   descr = 'this is a description' icon = 'sap-icon://account' )
-        ( title = 'row_02'  info = 'incompleted' descr = 'this is a description' icon = 'sap-icon://account' )
-        ( title = 'row_03'  info = 'working'     descr = 'this is a description' icon = 'sap-icon://account' )
-        ( title = 'row_04'  info = 'working'     descr = 'this is a description' icon = 'sap-icon://account' )
-        ( title = 'row_05'  info = 'completed'   descr = 'this is a description' icon = 'sap-icon://account' )
-        ( title = 'row_06'  info = 'completed'   descr = 'this is a description' icon = 'sap-icon://account' ) ).
+          ( title = `row_01`  info = `completed`   descr = `this is a description` icon = `sap-icon://account` )
+          ( title = `row_02`  info = `incompleted` descr = `this is a description` icon = `sap-icon://account` )
+          ( title = `row_03`  info = `working`     descr = `this is a description` icon = `sap-icon://account` )
+          ( title = `row_04`  info = `working`     descr = `this is a description` icon = `sap-icon://account` )
+          ( title = `row_05`  info = `completed`   descr = `this is a description` icon = `sap-icon://account` )
+          ( title = `row_06`  info = `completed`   descr = `this is a description` icon = `sap-icon://account` ) ).
 
       DATA(view) = z2ui5_cl_xml_view=>factory( ).
       DATA(page) = view->shell(
           )->page(
-              title           = 'abap2UI5 - List'
-              navbuttonpress  = client->_event_nav_app_leave( )
-                shownavbutton = client->check_app_prev_stack( ) ).
+              title          = `abap2UI5 - List`
+              navbuttonpress = client->_event_nav_app_leave( )
+              shownavbutton  = client->check_app_prev_stack( ) ).
 
       page->list(
-          headertext      = 'List Ouput'
+          headertext      = `List Ouput`
           items           = client->_bind_edit( t_tab )
           mode            = `SingleSelectMaster`
-          selectionchange = client->_event( 'SELCHANGE' )
+          selectionchange = client->_event( `SELCHANGE` )
           )->standard_list_item(
-              title       = '{TITLE}'
-              description = '{DESCR}'
-              icon        = '{ICON}'
-              info        = '{INFO}'
-              press       = client->_event( 'TEST' )
+              title       = `{TITLE}`
+              description = `{DESCR}`
+              icon        = `{ICON}`
+              info        = `{INFO}`
+              press       = client->_event( `TEST` )
               selected    = `{SELECTED}` ).
 
       client->view_display( view->stringify( ) ).
 
+    ELSEIF client->check_on_event( `SELCHANGE` ).
+      client->message_box_display( |go to details for item { t_tab[ selected = abap_true ]-title }| ).
     ENDIF.
 
-    CASE client->get( )-event.
-
-      WHEN 'SELCHANGE'.
-        client->message_box_display( `go to details for item ` && t_tab[ selected = abap_true ]-title ).
-    ENDCASE.
-
   ENDMETHOD.
+
 ENDCLASS.