Main Methdology steps to configure multi-languages application

I want to make my application multi-languagas and achieves following conditions:

• Navigation Bar has the list of languages that make the language changing easly from any in the appplication.
• The session must not recreated when the language changed.
• The user have ability to choose the language on the Login page before authenticated session created.
• The default browser language should be setted as default language when new non-authenticated session created (at Login Page).

What the main steps will be followed to apply the previous conditions on my Oracle Apex application? Try to apply these steps if you have two languages en and ar.

1. From Shared Components > Globalization set the Application Primary Language to English (en), then set Application Language Derived From to Item Preference (use item containing preference).
2. From Shared Components > Translate > Define application languages add Arabic (ar).
3. From Shared Components > Application Items add new item FSP_LANGUAGE_PREFERENCE.
4. From Shared Components > Lists > Navigation Bar add the entries which are their attributes defined in the following table:

5. From Shared Components > Application Processes add SET_LANG process, with the source code of PL/SQL language:

BEGIN
    APEX_UTIL.REDIRECT_URL(P_URL => '&APP_PAGE_ALIAS.' || '?SESSION=' || '&APP_SESSION.');
END;

then set its Condition Type as Request = Expression 1, where Expression 1 is LANG.

6. In Login Page which its PAGE_ID is 9999 add the following:

• Radio Group page item with of name P9999_LANG where the Page Action on Selection is Submit Page and the List of value is the following SQL query:

SELECT
    case
        WHEN :FSP_LANGUAGE_PREFERENCE = 'en' then 'English'
        WHEN :FSP_LANGUAGE_PREFERENCE = 'ar' then 'الإنجليزية'
    end as d,
    'en' as r
FROM DUAL

UNION ALL

SELECT
    case
        WHEN :FSP_LANGUAGE_PREFERENCE = 'en' then 'Arabic'
        WHEN :FSP_LANGUAGE_PREFERENCE = 'ar' then 'العربية'
    end as d,
    'ar' as r
FROM DUAL

• Add process in the Before Header Point, with the follwing PL/SQL code:

DECLARE
BROWSER_LANG VARCHAR(2) := substr(NVL(owa_util.get_cgi_env('HTTP_ACCEPT_LANGUAGE'),'en'),1,2);
BEGIN
    CASE 
        WHEN :FSP_LANGUAGE_PREFERENCE IS NULL AND :P9999_LANG IS NULL THEN
            :P9999_LANG := BROWSER_LANG;
            :FSP_LANGUAGE_PREFERENCE := BROWSER_LANG;
        ELSE
            NULL;
    END CASE;
END;

• Add process in the Processing Point and type Execute Code:

begin
    :FSP_LANGUAGE_PREFERENCE := :P9999_LANG;
end;

• Add the following Branch, in After Processing Point, and Behavior of Type Page or URL (Redirect) and Target Page 9999 (redirect to itself). and set value of Item P9999_LANG with value &P9999_LANG. with server-side conditon of TypeRequest = Valueand Value isP9999_LANG`.