A solution to automatically synchronize the value of page items on different pages, that all use the same LOV.
Useful if you want the user to be able to choose a value for (in this example) Empno, and to keep using that same value when he/she switches to another page.

This example uses 2 pages (1071 and 1072). Both have a page item based on the EMP_LOV LOV, that submit the page on change.
The value of these page items is synchronized by an Application Item, and two Application Process on page 0.
You can add any number of pages with this same type of item. As long as you name it P_xxx_EMPNO_FROM_LOV, you won't have to add any code to those new pages to get this to work.
You can choose a value from the select list, and switch between the 2 pages by using the button above, to see the effect of this setup.

Note: For the example to work, you also need to define an Application Item named F_EMPNO (it is not listed in the Code section below).
Note: Make sure the Application Processes on page 0 have very low/high ID's, to ensure they always run before/after any page actions/processes; e.g. -999 and 999.


Previous (abandoned) solution:
A previous version of this solution used a Dynamic Action with a jQuery selector, instead of the After Page Submit process. This lead to problems with session timeouts however, so that approach was abandoned. Too bad really, it was quite elegant (and didn't require the page items to submit the page).

More info on the cause: Bug 22924875 : FILE BROWSE BUTTON - JSON ERRORS FROM A DYNAMIC ACTION WHEN TIMEOUT IS REACHED

And still more info: https://community.oracle.com/thread/3907873?start=0&tstart=0
"If the session times out (idle or otherwise) and you then perform any dynamic action requiring a trip to the database for PL/SQL (regardless of what its function is) - this will unfortunately produce a browser error.
Correct, at least with DA's. With self-performed ajax calls you could try to account for this, but with DA's you can't. And since those DA ajax calls expect a JSON return, the return of HTML text will cause a javascript error, since jQuery (since jQuery's $.ajax is being used) will attempt to parse the return to an object."

List Of Values

Name
		EMP_LOV
Type
		Dynamic
Source
	Query	select ename || ' (' || trim(empno) || ')' as d , empno as r from emp order by 1

Item

Identification
	Sequence	10
	Name	P1071_EMPNO_FROM_LOV
	Display As	Select List
User Interface
	Region	App-wide Items (page 1/2)
List Of Values
	Named LOV	EMP_LOV
	Display Extra Values	No
	Display Null Value	Yes
	List of values definition	select ename || ' (' || trim(empno) || ')' as d , empno as r from emp order by 1
Advanced
	Warn on Unsaved Changes	Page Default
Source
	Source Used	Only when current value in session state is null
	Source Type	Always Null

Item

Identification
	Sequence	20
	Name	P1071_F_EMPNO
	Display As	Display Only
User Interface
	Region	App-wide Items (page 1/2)
List Of Values
	Display Null Value	No
Advanced
	Warn on Unsaved Changes	Page Default
Source
	Source Used	Always, replacing any existing value in session state
	Source Type	Item (application or page item name)
	Source value or expression	F_EMPNO

Item

Note: This object is located on page 1072

Identification
	Sequence	10
	Name	P1072_EMPNO_FROM_LOV
	Display As	Select List
User Interface
	Region	App-wide Items <span style="color:red;">(page 2/2)</span>
List Of Values
	Named LOV	EMP_LOV
	Display Extra Values	Yes
	Display Null Value	Yes
	List of values definition	select ename || ' (' || trim(empno) || ')' as d , empno as r from emp order by 1
Advanced
	Warn on Unsaved Changes	Page Default
Source
	Source Used	Only when current value in session state is null
	Source Type	Always Null

Process

Note: This object is located on page 0

Name
	Button Name	set page item Pxxx_EMPNO_FROM_LOV
	Type	Anonymous Block
Process Point
	Sequence	-999
	Process Point	On Load: Before Header (page template header)
Source
	Process	declare v_item_name varchar2(100) := 'P' || :APP_PAGE_ID || '_EMPNO_FROM_LOV'; v_item_id number; begin select max(a.item_id) into v_item_id from apex_application_page_items a where a.application_id = :APP_ID and a.page_id = :APP_PAGE_ID and a.display_as_code = 'NATIVE_SELECT_LIST' -- only select lists and a.lov_named_lov = 'EMP_LOV' -- the "master" LOV ; if v_item_id is not null -- only continue when the page item exists -- and :F_EMPNO is not null -- optional: only continue when the application item is not null then -- all is OK so we can set the page item apex_util.set_session_state( v_item_name, :F_EMPNO ); end if; end;

Process

Note: This object is located on page 0

Name
	Button Name	set app item F_EMPNO on LOV selection
	Type	Anonymous Block
Process Point
	Sequence	999
	Process Point	On Submit: After Page Submission - After Computations and Validations
Source
	Process	declare v_item_name varchar2(100) := 'P' || :APP_PAGE_ID || '_EMPNO_FROM_LOV'; v_item_id number; v_empno varchar2( 20); begin apex_debug.message('v_item_name='||v_item_name); -- check if the page item exists, and if it is a select list that is filled by the correct LOV select max(a.item_id) into v_item_id from apex_application_page_items a where a.application_id = :APP_ID and a.page_id = :APP_PAGE_ID and a.item_name = v_item_name and a.display_as_code = 'NATIVE_SELECT_LIST' -- only select lists and a.lov_named_lov = 'EMP_LOV' -- the "master" LOV ; apex_debug.message('v_item_id='||v_item_id); if v_item_id is not null -- only continue when the page item exists -- and v_empno is not null -- optional: only continue when the page item is not null then v_empno := v(v_item_name); apex_debug.message('v_empno='||v_empno); -- note: this would be the place for any table updates, if you want to store the selected value for future use apex_util.set_session_state( 'F_EMPNO', v_empno ); end if; end;