client-scripts

To validate form fields before submission in ServiceNow, you use an onSubmit client script combined with the g_form API to check field values and return false to cancel the save if validation fails.

ServiceNow onLoad client scripts execute when a form renders, ideal for setting default values, whereas onChange scripts trigger dynamically when a specific field's value is modified by the user.

GlideAjax enables asynchronous server communication in ServiceNow client scripts by calling a script include, passing parameters, and processing the returned data to update form fields dynamically.

Yes, the g_user object in ServiceNow client scripts provides client-side properties like userName and roles, allowing you to check user permissions without making additional server calls.

Performance best practices for ServiceNow client-side scripting include avoiding synchronous server calls, minimizing DOM manipulation, and using GlideAjax efficiently to prevent form load delays.

Use the onCellEdit client script in ServiceNow when you need to validate or manipulate data directly within a list view cell, whereas onChange is restricted to standard form field modifications.