how to populate field of type List using onChange client script with multiple values

[Alon Grod]

how to populate field of type List using onChange client script with multiple values

[Abhishek Pal]

Hi @Alon Grod ,

Yes, you can populate multiple values into a List type field from an onChange Client Script.

A List field stores multiple sys_ids from its referenced table.

If you already know the sys_ids, use an array:

function onChange(control, oldValue, newValue, isLoading) {

if (isLoading || !newValue)
return;

var values = [
'SYS_ID_1',
'SYS_ID_2',
'SYS_ID_3'
];

g_form.setValue('u_list_field', values);
}

Replace:

u_list_field

with your List field name.

Important:
The values must be sys_ids from the table referenced by the List field.

For example, if u_users is a List field referencing sys_user:

function onChange(control, oldValue, newValue, isLoading) {

if (isLoading)
return;

if (!newValue) {
g_form.clearValue('u_users');
return;
}

var users = [
'6816f79cc0a8016401c5a33be04be441',
'62826bf03710200044e0bfc8bcbe5df1'
];

g_form.setValue('u_users', users);
}

If the values have to be retrieved dynamically based on the field changed, use GlideAjax.

Example:

Client Script:

function onChange(control, oldValue, newValue, isLoading) {

if (isLoading)
return;

if (!newValue) {
g_form.clearValue('u_users');
return;
}

var ga = new GlideAjax('GetUsersForList');

ga.addParam(
'sysparm_name',
'getUsers'
);

ga.addParam(
'sysparm_value',
newValue
);

ga.getXMLAnswer(function(answer) {

if (!answer) {
g_form.clearValue('u_users');
return;
}

var users = JSON.parse(answer);

g_form.setValue(
'u_users',
users
);
});
}

Client-callable Script Include:

var GetUsersForList = Class.create();

GetUsersForList.prototype =
Object.extendsObject(AbstractAjaxProcessor, {

getUsers: function() {

var value =
this.getParameter('sysparm_value');

var users = [];

var gr =
new GlideRecord('sys_user');

gr.addActiveQuery();

// Add your actual condition here.
// Example:
// gr.addQuery('department', value);

gr.query();

while (gr.next()) {
users.push(
gr.getUniqueValue().toString()
);
}

return JSON.stringify(users);
},

type: 'GetUsersForList'
});

Recommended approach:

onChange field
-> GlideAjax
-> Query required records server-side
-> Return array of sys_ids
-> g_form.setValue()
-> List field populated with multiple records

If instead you want to ADD new values while preserving the values already present in the List field, use:

var existing =
g_form.getValue('u_users');

var values =
existing ? existing.split(',') : [];

values.push('NEW_SYS_ID');

g_form.setValue(
'u_users',
values
);

Before adding values, I would also remove duplicates:

values = Array.from(
new Set(values)
);

Important points:

- The target field must be Type = List.
- Its referenced table must match the sys_ids being supplied.
- Use sys_ids, not names/display values.
- Use GlideAjax when records need to be queried dynamically.
- Do not use client-side GlideRecord for this requirement.
- If you want to replace the existing values, call setValue() directly.
- If you want to preserve existing values, read them first and append the new sys_ids.

ServiceNow officially supports passing an array of sys_ids to g_form.setValue() when the target field is a Glide List.

Hope this helps!

If this response helped, please mark it as Helpful.
If it resolves your issue, please Accept it as Solution.

Kind Regards,
Abhishek Pal

[Ankur Bawiskar]

@Alon Grod 

simply set string of comma separated sysIds using g_form.setValue()

what did you try and what didn't work?

💡 If my response helped, please mark it as correct ✅ and close the thread 🔒— this helps future readers find the solution faster! 🙏

[Alon Grod]

@Ankur Bawiskar @Abhishek Pal @Risto D_od_o 

This field of type List with predefined choices

[Abhishek Pal]

Hi @Alon Grod ,

Thanks for clarifying.

Since your field is Type = List with predefined choices and is NOT referencing another table, you do not need sys_ids or GlideAjax.

You should populate it using the internal VALUES of the predefined choices, not their display labels.

For example, suppose your List field is:

u_environment

and the predefined choices are:

Label Value
Production production
Development development
Test test

To populate multiple selections from an onChange Client Script:

function onChange(control, oldValue, newValue, isLoading) {

if (isLoading)
return;

if (newValue == 'some_value') {

g_form.setValue(
'u_environment',
'production,development,test'
);

} else {

g_form.clearValue('u_environment');
}
}

The important part is:

production,development,test

These must be the choice VALUES, not:

Production, Development, Test

You can verify the values by:

Right-click the field
-> Configure Choices

or:

Show Choice List

and check the Value column.

If you already have some selected values and want to append additional choices instead of replacing them:

var existing = g_form.getValue('u_environment');

var values = existing
? existing.split(',')
: [];

var valuesToAdd = [
'production',
'test'
];

valuesToAdd.forEach(function(value) {
if (values.indexOf(value) == -1)
values.push(value);
});

g_form.setValue(
'u_environment',
values.join(',')
);

So for your case:

List with reference table
-> use referenced record sys_ids

List with predefined choices
-> use internal choice values

Since you confirmed yours is the second type, use the predefined choice values.

One design consideration:

ServiceNow's standard Choice field itself supports only one selected value. A Glide List can hold multiple values, but ServiceNow generally models Glide Lists as collections of references. If this field becomes important for integrations/reporting or needs to work consistently across different Workspace experiences, a small reference table containing those predefined options is the more robust data model.

For your current onChange requirement in the standard form, however, try the comma-separated internal choice values first.

Official ServiceNow references:

Choice Lists:
https://www.servicenow.com/docs/r/platform-administration/c_ChoiceLists.html

View Choice List Definitions:
https://www.servicenow.com/docs/r/platform-administration/t_ViewChoiceListDefinitions.html

Related ServiceNow Community discussion for Glide List fields with choices:
https://www.servicenow.com/community/developer-forum/how-to-manage-choices-in-glide-list-type-field/...

Hope this helps!

If this response helped, please mark it as Helpful.
If it resolves your issue, please Accept it as Solution.

Kind Regards,
Abhishek Pal