---
sourceDocument: Xanadu API Reference
sourceDocumentLink: https://servicenow-prod.fluidtopics.net/r/xanadu/api-reference

 Release :

    - xanadu

ft:locale :

    - en-US

ft:publication_title :

    - Xanadu API Reference

ft:clusterId :

    - crapiref

bundleId :

    - crapiref

workflow :

    - Creator


---

# Client scripts

# Client scripts {#ariaid-title1}

* Release version: Xanadu
* 
* Updated August 1, 2024
* 
* ![](https://www.servicenow.com/docs/portal-asset/ico-clock) 3 minutes to read

Client scripts allow the system to run JavaScript on the client (web browser) when
client-based events occur, such as when a form loads, after form submission, or when a field
changes value.
<br />

Use client scripts to configure forms, form fields, and field values while the user is using
the form. Client scripts can:  
* make fields hidden or visible
* make fields read only or writable
* make fields optional or mandatory based on the user's role
* set the value in one field based on the value in other fields
* modify the options in a choice list based on a user's role
* display messages based on a value in a field
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Warning:  
Client scripts are intended to optimize the user experience on a form. Client scripts are not meant to protect unwanted access to data.

To prevent unwanted access to data, ensure that sensitive fields are hidden or read-only through ACLs or data policies.

For more information, see [Access Control List Rules](https://www.servicenow.com/docs/access?context=access-control-rules&version=xanadu&pubname=xanadu-platform-security&ft:locale=en-US) or [Data policy](https://www.servicenow.com/docs/access?context=c_DataPolicy&version=xanadu&pubname=xanadu-platform-administration&ft:locale=en-US).

## Where client scripts run {#client-scripts__section_y1n_4z5_zz}

With the exception of onCellEdit() client scripts, client scripts only apply to forms and search pages. If you create a client script to control field values on a form, you must use one of these other methods to control field values when on a list.

* Create an access control to restrict who can edit field values.
* Create a business rule to validate content.
* Create a data policy to validate content.
* Create an onCellEdit() client script to validate content.
* Disable list editing for the table.
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Note:  
Client scripts are not supported on ServiceNow mobile applications.

## Client script form {#client-scripts__section_yjd_hvg_zz}

{#client-scripts__table_trz_nvg_zz__entry__2}

| Field | Description |
|-|-|
| Name | Name of the client script. |
| Table | Table to which the client script applies. |
| UI Type | Target user interface to which the client script applies. |
| Type | onLoad() --- runs when the system first renders the form and before users can enter data. Typically, onLoad() client scripts perform client-side-manipulation of the current form or set default record values. onSubmit() --- runs when a form is submitted. Typically, onSubmit() scripts validate things on the form and ensure that the submission makes sense. An onSubmit() client script can cancel form submission by returning a value of false. onChange() --- runs when a particular field value changes on the form. The onChange() client script must specify these parameters. * control: the DHTML widget whose value changed. Note: control is not accessible in mobile and service portal. * oldValue: the value the widget had when the record was loaded. Note: Old values aren't returned for the HTML field type. * newValue: the value the widget has after the change. * isLoading: identifies whether the change occurs as part of a form load. * isTemplate: identifies whether the change occurs as part of a template load. {#client-scripts__ul_bsg_d2r_n4} onCellEdit() --- runs when the list editor changes a cell value. The onCellEdit() client script must specify these parameters. * sysIDs: an array of the sys_ids for all items being edited. * table: the table of the items being edited. * oldValues: the old values of the cells being edited. * newValue: the new value for the cells being edited. * callback: a callback that continues the execution of any other related cell edit scripts. If true is passed as a parameter, the other scripts are executed or the change is committed if there are no more scripts. If false is passed as a parameter, any further scripts are not executed and the change is not committed. {#client-scripts__ul_qm5_z2r_n4} |
| Field Name | Name of the field to which the script applies. Available only if the script responds to a field value change (onChange or onCellEdit script types). |
| Application | Application where this client script resides. |
| Active | Enables the client script when selected. Unselect this field to disable the client script. |
| Inherited | Indicates whether the client script applies to extended tables. |
| Global | If true, the client script runs on all views of the table. |
| View | Only visible when Global is unselected. Views on which the client script will run. |
| Description | Content describing the functionality and purpose of the client script. |
| Messages | Text string (one per line) available to the client script as localized messages using getmessage('\[message\]'). For additional information, see [Translate a client script message](https://www.servicenow.com/docs/access?context=t_TranslateAClientScriptMessage&version=xanadu&pubname=xanadu-platform-administration&ft:locale=en-US). |
| Script | Contains the client script. |
| Isolate script | New client scripts are run in strict mode, with direct DOM access disabled. Access to jQuery, prototype, and the window object are also disabled. To disable this on a per-script basis, configure this form and select the Isolate script check box. To disable this feature for all new globally-scoped client-side scripts set the system property glide.script.block.client.globals to false. |
[ ]

{#client-scripts__table_trz_nvg_zz}