Update dx.md

Author: oblomov-dev

docs/advanced/technical/dx.md

@@ -56,9 +56,26 @@ START-OF-SELECTION.
 ```
 this is thew wy we can do it with abap2ui5:
 ```abap
-"app
-"app
-"app
+CLASS z2ui5_cl_app_hello_world DEFINITION PUBLIC CREATE PUBLIC.
+  PUBLIC SECTION.
+    INTERFACES z2ui5_if_app.
+    DATA pa_arbgb TYPE string.
+ENDCLASS.
+
+CLASS z2ui5_cl_app_hello_world IMPLEMENTATION.
+  METHOD z2ui5_if_app~main.
+
+    IF client->check_on_init( ).
+      client->view_display(
+        z2ui5_cl_xml_view=>factory(
+            )->input( client->_bind_edit( pa_arbgb )
+            )->button( text  = 'post' press = client->_event( 'POST' ) ) ).
+    ELSEIF client->get( )-event = 'POST'.
+      client->message_box_display( |Input: { pa_arbgb }| ).
+    ENDIF.
+
+  ENDMETHOD.
+ENDCLASS.
 ```
 
 ### ALV