Mastering GlideAjax and Script Includes: A Guide for ServiceNow Developers

[BillMartin]

Introduction:

When developing in ServiceNow, you’ll often encounter scenarios where you need to fetch additional data from the ServiceNow database server without refreshing the page. One powerful way to achieve this is by using GlideAjax with a ServiceNow Script Include.

In this guide, I’ll show you how ServiceNow can dynamically retrieve and display incident details when a field value changes on a form.

What You’ll Learn in This Guide:

• How to create a Script Include using GlideRecord to query the incident table.
• How to write an onChange Client Script that communicates with the Script Include using GlideAjax.
• How to properly handle XML responses in client scripts.
• How to use g_form functions to update form fields and display messages.
• Debugging best practices with gs.info() for server-side logs and console.log() for client-side.

 

Step 1: Create the Script Include

The Script Include extends AbstractAjaxProcessor, allowing it to handle AJAX requests from client scripts. The method getIncidentDetails retrieves the incident details from the incident table and returns the data in JSON format.

Step 2: Create the onChange Client Script

Next, create an onChange Client Script that triggers when the number field is updated.

This script sends an AJAX request to the server and retrieves incident details. It parses the XML response and uses g_form functions to update the form fields and display messages.

 

Step 3: Debugging and Logs

To debug your scripts effectively:

1. Use gs.info() in the Script Include to track server-side events.
2. Use console.log() in the client script to verify the flow of data on the client side.
3. Check the System Logs in ServiceNow for errors or debugging messages.

 

ServiceNow GlideAjax Use Case Example

Imagine a form where a user needs to enter an incident number. With this setup, when the incident number is entered or changed, the system automatically fetches the related details (e.g., short description, state, caller) and displays them on the form.

Watch the Full Tutorial on YouTube! 🎥

Want to see this solution in action? I’ve created a detailed walkthrough showing how to build and test both the Script Include and Client Script.

This video covers:

• Creating and configuring the Script Include.
• Writing the onChange Client Script.
• Testing the solution and troubleshooting.
• Best practices for debugging in ServiceNow.

 

Key Takeaways:

• GlideAjax allows seamless client-to-server communication without page refreshes.
• GlideRecord is used to query ServiceNow tables on the server side.
• Proper XML response handling is essential for AJAX-based solutions.
• Debugging is easier with gs.info() and g_form.addInfoMessage().

 

Join the Conversation!

💬 Have questions or need help with your ServiceNow development projects? Share your thoughts in the comments below .

#ServiceNow #GlideAjax #ScriptInclude #ClientScript #GlideRecord #TechTutorial