How to get the current Page id in Portal from PLSQL

Here is a simple way to retrieve the current Portal page id, you can add it as a PLSQL item to the page.

declare
v_page varchar2(200);
begin
htp.p('hello world');
v_page := portal.wwpro_api_parameters.get_value( '_pageid', 'a');
htp.p('page: ' || v_page);
end;