Update hello_world.md

Author: oblomov-dev

docs/get_started/hello_world.md

@@ -5,7 +5,6 @@ outline: [2, 4]
 
 Just copy the following class into your system:
 
-Build a class:
 ```abap
 CLASS zcl_app_hello_world DEFINITION PUBLIC.
   PUBLIC SECTION.
@@ -24,7 +23,27 @@ Go back to the landing page in your browser and enter `ZCL_APP_HELLO_WORLD` to l
 While the HTTP handler has to distinguish between Standard ABAP and ABAP for Cloud, the apps themselves are independent. You're free to choose whether to build your apps with ABAP Cloud compatibility.
 :::
 
-### Idea
+### View Display
+Let's add a view to show some text:
+```abap
+CLASS zcl_app_hello_world DEFINITION PUBLIC.
+  PUBLIC SECTION.
+    INTERFACES z2ui5_if_app.
+ENDCLASS.
+
+CLASS zcl_app_hello_world IMPLEMENTATION.
+  METHOD z2ui5_if_app~main.
+
+    DATA(view) = z2ui5_cl_xml_view=>factory(
+      )->page( `abap2UI5 - Hello World`
+      )->text( `My Text` ).
+    client->view_display( view->stringify( ) ).
+
+  ENDMETHOD.
+ENDCLASS.
+```
+
+### Info
 abap2UI5 follows a thin-frontend model: the browser only renders UI5 views, while all logic, state, and data handling stay in ABAP on the server. Three ideas to keep in mind before writing code:
 
 - **One method, many calls.** The framework calls your app's `main` method on every roundtrip — on the initial start *and* after every user interaction (button press, input change, navigation).
@@ -43,8 +62,9 @@ The `client` object is your only entry point into the framework. Use it to show
 
 → *For a deeper look at the lifecycle and framework internals, see [How It All Works](/technical/how_it_all_works) and [Concept](/technical/concept).*
 
-### View Display
-Let's add a view to show some text:
+### Events
+
+Let's extend the code with some event handling:
 ```abap
 CLASS zcl_app_hello_world DEFINITION PUBLIC.
   PUBLIC SECTION.
@@ -54,16 +74,25 @@ ENDCLASS.
 CLASS zcl_app_hello_world IMPLEMENTATION.
   METHOD z2ui5_if_app~main.
 
-    DATA(view) = z2ui5_cl_xml_view=>factory(
-      )->page( `abap2UI5 - Hello World`
-      )->text( `My Text` ).
-    client->view_display( view->stringify( ) ).
+    IF client->check_on_init( ).
+
+        DATA(view) = z2ui5_cl_xml_view=>factory(
+          )->page( `abap2UI5 - Hello World`
+          )->text( `My Text`
+          )->button( text = `post` press = client->_event( `POST` ) ).
+        client->view_display( view->stringify( ) ).
+
+    ELSEIF client->check_on_event( `POST` ).
+
+        client->message_box_display( `Hello World!` ).
+
+    ENDIF.
 
   ENDMETHOD.
 ENDCLASS.
 ```
 
-### Event Handler
+### Info
 The framework calls the `main` method on every roundtrip — on initialization and after every user interaction (button press, input submit, etc.):
 
 ```text
@@ -78,41 +107,12 @@ The framework calls the `main` method on every roundtrip — on initialization a
 └─────────┘       └──────────┘       └──────────┘
 ```
 
-To distinguish between lifecycle events, use `CASE abap_true`:
+To distinguish between lifecycle events, check for the following events:
 
 - `client->check_on_init( )` — first call when the app starts
 - `client->check_on_event( )` — user triggered an event (e.g., button press)
-- `client->check_on_navigated( )` — returned from another app via navigation
-
-Each `check_*` method returns `abap_true` only for its specific phase, so `CASE abap_true` acts as a dispatcher:
-```abap
-CLASS zcl_app_hello_world DEFINITION PUBLIC.
-  PUBLIC SECTION.
-    INTERFACES z2ui5_if_app.
-ENDCLASS.
-
-CLASS zcl_app_hello_world IMPLEMENTATION.
-  METHOD z2ui5_if_app~main.
-
-    CASE abap_true.
-
-      WHEN client->check_on_init( ).
-
-        DATA(view) = z2ui5_cl_xml_view=>factory(
-          )->page( `abap2UI5 - Hello World`
-          )->text( `My Text`
-          )->button( text = `post` press = client->_event( `POST` ) ).
-        client->view_display( view->stringify( ) ).
-
-      WHEN client->check_on_event( `POST` ).
-
-        client->message_box_display( `Hello World!` ).
-
-    ENDCASE.
 
-  ENDMETHOD.
-ENDCLASS.
-```
+Each `check_*` method returns `abap_true` only for its specific phase, so is acts as a dispatcher:
 
 ### Data Flow
 Finally, add a public attribute to send data to the backend: