Hash

The class

" @keywords routing mode fresh default off navigation restart new instance nav_app_call hash_routing
" @summary Hash routing in mode FRESH: the URL names the CLASS, so Back and a bookmark restart the app as a new instance.
" @docs https://abap2ui5.github.io/docs/cookbook/event_navigation/navigation/hash
"! Hash-based app routing (UI5 Router style), mode FRESH:
"! follow_up_action( cs_event-hash_routing ) with mode FRESH makes the URL
"! mirror the running app by CLASS only ('#/app/[CLASS]'). Browser Back/Forward - and a
"! reload or a bookmark - therefore start the app FRESH: the input and the
"! counter are gone.
"!
"! Put in some state (type / raise the counter), open the detail page
"! (z2ui5_cl_smp_app_469) via client->nav_app_call( ), then press the BROWSER
"! Back button and watch this page - it comes back empty.
"!
"! z2ui5_cl_smp_app_480 is the same demo in mode KEEP, where the state survives.
"! The third mode is DEFAULT - no routing at all, the hash left untouched, the
"! way an app behaves before it ever calls hash_routing: the switch below
"! turns the routing off with it and on again with FRESH.
CLASS z2ui5_cl_smp_app_468 DEFINITION PUBLIC.

  PUBLIC SECTION.
    INTERFACES z2ui5_if_app.

    DATA input   TYPE string.
    DATA routing TYPE abap_bool.

  PROTECTED SECTION.
    DATA counter TYPE i.
    DATA client  TYPE REF TO z2ui5_if_client.

    METHODS on_event.
    METHODS view_display.

  PRIVATE SECTION.
ENDCLASS.


CLASS z2ui5_cl_smp_app_468 IMPLEMENTATION.

  METHOD z2ui5_if_app~main.

    me->client = client.

    IF client->check_on_navigated( ).
      view_display( ).

    ELSEIF client->check_on_event( ).
      on_event( ).
    ENDIF.

  ENDMETHOD.


  METHOD on_event.

    CASE client->get_event( ).

      WHEN `INC`.
        counter = counter + 1.
        view_display( ).

      WHEN `GO_DETAIL`.
        client->nav_app_call( NEW z2ui5_cl_smp_app_469( ) ).

      WHEN `ROUTING`.
        " the mode is remembered on the app, so switching it is one action:
        " DEFAULT leaves the hash alone from now on - Back/Forward leave the
        " page, the framework default - and FRESH puts the class back in
        client->follow_up_action( val   = client->cs_event-hash_routing
                                  t_arg = VALUE #( ( COND #( WHEN routing = abap_true
                                                             THEN client->cs_nav_mode-fresh
                                                             ELSE client->cs_nav_mode-default ) ) ) ).
        client->message_toast_display( COND #( WHEN routing = abap_true
                                               THEN `routing mode fresh - the URL carries the class`
                                               ELSE `routing mode default - the URL is left untouched` ) ).

    ENDCASE.

  ENDMETHOD.


  METHOD view_display.

    " configure the routing mode once - the framework remembers it on the app
    " and re-sends it whenever the frontend may not hold it (page load,
    " Back/Forward restore, navigation hops)
    IF client->check_on_init( ).
      routing = abap_true.
      client->follow_up_action( val   = client->cs_event-hash_routing
                                t_arg = VALUE #( ( client->cs_nav_mode-fresh ) ) ).
    ENDIF.

    DATA(view) = z2ui5_cl_ui5_view_builder=>factory(
        )->ele( n = `View` ns = `mvc`
            )->a( n = `displayBlock` v = `true`
            )->a( n = `height`       v = `100%`
            )->a( n = `xmlns`        v = `sap.m`
            )->a( n = `xmlns:mvc`    v = `sap.ui.core.mvc`
            )->a( n = `xmlns:form`   v = `sap.ui.layout.form`
            )->a( n = `xmlns:layout` v = `sap.ui.layout` ).
    DATA(page) = view->ele( `Shell`
        )->ele( `Page`
            )->a( n = `title`          v = `abap2UI5 - Hash - Routing Mode FRESH (a New Instance)`
            )->a( n = `showNavButton`  b = client->check_app_prev_stack( )
            )->a( n = `navButtonPress` v = client->_event_nav_app_leave( ) ).

    page->tag( `MessageStrip`
        )->a( n = `text`     v = `Add some state (type / raise the counter), open the detail page, then press your ` &&
                   `BROWSER Back button and watch this page.`
        )->a( n = `type`     v = `Information`
        )->a( n = `showIcon` b = abap_true
        )->a( n = `class`    v = `sapUiSmallMargin` ).

    DATA(form) = page->ele( n = `Grid` ns = `layout`
        )->a( n = `defaultSpan` v = `L6 M12 S12`
        )->ele( n = `content` ns = `layout`
            )->ele( n = `SimpleForm` ns = `form`
                )->a( n = `title` v = `Routing mode fresh`
                )->ele( n = `content` ns = `form` ).

    form->tag( `Label`
        )->a( n = `text` v = `1. Some state - type here` ).
    form->tag( `Input`
        )->a( n = `value` v = client->_bind( input ) ).

    form->tag( `Label`
        )->a( n = `text` v = `and raise a counter` ).
    form->tag( `Button`
        )->a( n = `press` v = client->_event( `INC` )
        )->a( n = `text`  t = |increment ({ counter })| ).

    form->tag( `Label`
        )->a( n = `text` v = `2. Navigate forward` ).
    form->tag( `Button`
        )->a( n = `press` v = client->_event( `GO_DETAIL` )
        )->a( n = `text`  v = `go to the detail page (nav_app_call)`
        )->a( n = `type`  v = `Emphasized` ).

    form->tag( `Label`
        )->a( n = `text` v = `3. Or switch the routing off again (mode default)` ).
    form->tag( `Switch`
        )->a( n = `state`         v = client->_bind( routing )
        )->a( n = `customTextOn`  v = `fresh`
        )->a( n = `customTextOff` v = `off`
        )->a( n = `change`        v = client->_event( `ROUTING` ) ).

    page->tag( `MessageStrip`
        )->a( n = `text`     v = `fresh: the URL carries the class only (#/app/<CLASS>). After the detail page, the ` &&
                   `browser Back button starts this app FRESH - input and counter are reset.`
        )->a( n = `type`     v = `Success`
        )->a( n = `showIcon` b = abap_true
        )->a( n = `class`    v = `sapUiSmallMargin` ).

    client->view_display( view->stringify( ) ).

  ENDMETHOD.

ENDCLASS.