How to access Oracle Apex variables from Javascript?

Question

I'm using Oracle APEX but am unsure how to access the following variables from an external javascript file that may be located on the app server or stored in Shared Components -> Static Files.

:APP_ID
:APP_PAGE_ID
:APP_SESSION

How can I reference the values for each of the above from javascript (stored as a Static File)?

Answer 1

These values get rendered on the page as hidden items like this:

<input type="hidden" name="p_flow_id" value="4000" id="pFlowId" />
<input type="hidden" name="p_flow_step_id" value="4150" id="pFlowStepId" />
<input type="hidden" name="p_instance" value="6528421540413702" id="pInstance" />

so you can reference them as:

$v('pFlowId') // APP_ID
$v('pFlowStepId') // APP_PAGE_ID
$v('pInstance') // SESSION

It's a pity they aren't named the same as the session state!

Answer 2

Since APEX 5 you can also use apex.item instead of $v, as described here:

apex.item('pFlowId').getValue() // APP_ID
apex.item('pFlowStepId').getValue() // APP_PAGE_ID
apex.item('pInstance').getValue() // APP_SESSION

Both $v and apex.item require that the "apex" namespace has already been loaded at the time you try to access the values. If you ever need to access them before that, you can also use JavaScript only instead:

document.getElementById('pFlowId').value; // APP_ID
document.getElementById('pFlowStepId').value; // APP_PAGE_ID
document.getElementById('pInstance').value; // APP_SESSION