Oracle APEX: How to Verify Hidden Page Item Values

Overview

Oracle APEX Debug is a troubleshooting tool that provides detailed information about page processing, session state, and application execution. By reviewing the Debug Log and Session State, developers can trace application behavior and identify the root cause of issues

Scenario

Suppose an Interactive Grid is filtered using four hidden Page Items. The grid is not returning the expected records, and the developer needs to confirm whether the Page Items contain the correct values during execution

In this article, we will discuss how to verify that the values stored in Hidden Page Items are correct by using Oracle APEX Debug and the Session viewer for a point-in-time snapshot.

Hidden Item

In Oracle APEX, a Hidden Page Item stores values that are not visible to end users but remain available during page processing, validations, computations, Dynamic Actions, and PL/SQL execution

Requirement:  Before following these steps, ensure we have:

1.      An Interactive Grid region on your APEX page.
2.     Four Page Items configured with the type Hidden.
3.    An Interactive Grid region populated using these Hidden Page Items as SQL bind variables.

How to Create a Hidden Page Item

In this article we create four Hidden Items:

·         P398_SER_REQ

·         P398_EMP_ID

·         P398_VEHICLE_ID

·         P398_VEHICLE_NO

Step 1: Open Page Designer

1. Log into your APEX workspace
2. Navigate to the page

Step 2: Add a New Page Item

1. Right-click on the Items region
2. Select Create Page Item

Step 3: Configure and Save

1. Give the item a meaningful name
2. Set Type to Hidden
3. Set Value Protected to No

4. Set Default Value if needed
5. Click Save

 How to Use Hidden Items in a Region SQL Query

Once the hidden items exist, you can reference them directly in a region's SQL query using APEX bind variable syntax: :ITEM_NAME.

 Query for an Interactive Grid region:

SELECT v.vehicle_no || ' - ' || v.vehicle_desc

FROM veh_request req

JOIN veh_setup v ON req.vehicle_id = v.vehicle_id

WHERE req.bill_posted = 'Y'

AND req.employee_id = :P398_EMP_ID

AND TRIM(v.vehicle_id) = :P398_VEHICLE_ID

 Key points:

•        The colon prefix (:) tells APEX to substitute the current session value of that page item.

•        The item must exist on the same page, or be a global application item.

•        If a hidden item is NULL, the WHERE condition will filter out all rows

•        If the hidden item is set by a Dynamic Action or button process, make sure it is listed under Page Items to Submit in the Action, otherwise APEX will not pass the updated value to the server.

Steps: Verifying Hidden Page Item Values

 Step 1: Enable Debug Mode

1. Open the APEX application page you want to investigate.
2. Locate the Developer Toolbar at the bottom of the page.
3. Click the Debug button.Click Enable Debug → Info (default)

Step 2: Interact with the Page

Perform the action you want to investigate, such as:

·         Submitting the page

·         Clicking a button

·         Triggering a Dynamic Action

APEX records all processing steps, including the values assigned to hidden Page Items.

Step 3: View the Debug Log

1. Open the Developer Toolbar.
2. Click Debug.
3. Click View Debug.
4. Click the most recent session to view the detailed log.

Step  4: Verify Hidden Page Item Values via Session View

1. Open the Developer Toolbar
2. Click Session.
3. Click View Session State
4. Review the associated entries.
5. In the Session State panel, locate your hidden items by name.
6. Confirm that each item holds the expected value

Note:  Each row in the Session View shows the item name and its current value. A blank or NULL value for a hidden item that should be populated indicates a problem in the computation, process, or Dynamic Action or the Page Items to Submit configuration.

Conclusion:

By combining the creation of Hidden Page Items, correct SQL bind variable syntax, and APEX's built-in Debug and Session View tools, developers can quickly confirm whether filter values are being passed correctly to a region query.

 If the hidden Page Item values appear correctly in the Session View the page is processing them as expected. If the values are missing or incorrect, review:

•        The computations, processes, or Dynamic Actions responsible for setting the items

•        Whether the items are listed under Page Items to Submit

•        The SQL query to ensure the bind variable names exactly match the item names