ServiceNow Client Scripts: Using the isMemberOf Function for User Group Validation

In ServiceNow client scripts, developers often need to tailor form behavior based on a user's group memberships. The isMemberOf function is a server-side method that quickly checks if the current user belongs to a specified group, returning true or false.

This is extremely useful for implementing conditional logic—for example, showing certain form fields or allowing specific actions only for members of a particular group.

By leveraging group membership, ServiceNow administrators can allow or disallow certain behaviors and levels of access for users based on their roles in the organization.

Common scenarios include:

• Making fields read-only for non-members

• Hiding UI options for users outside a group

• Enforcing approvals only if the user is part of a designated team

In essence, the isMemberOf function is a handy tool for user group validation in scripts, ensuring that form interactions respect the user's group privileges.

However, using isMemberOf isn't straightforward in every context. While it works well in server-side scripts (business rules, script includes, ACLs, etc.), developers often run into issues when trying to use it directly in client-side scripting.

In the following sections, we'll explore why isMemberOf doesn't work as expected in client scripts, and we'll walk through proven solutions and best practices for checking group membership on the client side in ServiceNow.

Understanding the Issue

A common mistake new ServiceNow developers make is attempting to call the isMemberOf function directly within a client script.

For Example:

gs.getUser().isMemberOf('Group Name');

or

g_user.isMemberOf('Group Name');

This approach does not work and can lead to confusion.

The reason is that isMemberOf is part of ServiceNow's server-side API (via the GlideSystem user object) and is not available in the client-side scripting environment.

In other words, client scripts run in the user's browser and have access only to limited client-side APIs – gs.getUser() and its methods (including isMemberOf) are not accessible there.

When a developer tries to use isMemberOf in a client script, one of two things typically happens:

• Either the script throws a runtime error (because gs is undefined on the client)

• It simply always evaluates to false/empty and the logic never behaves as intended

It's important to understand that ServiceNow separates what can be done on the server vs the client for security and performance reasons. The isMemberOf function can only be used on the server side (in business rules, script includes, ACLs, etc.), so we need a different approach to leverage that information on forms.

The mistake, therefore, is not in using isMemberOf per se (the function itself is valid), but in trying to use it in the wrong place.

In summary, the issue is: gs.getUser().isMemberOf() is a server-side call and will not execute in client scripts. Understanding this limitation is the first step towards finding a solution.

Next, we'll see how to correctly check a user's group membership on the client side by using a combination of server logic and client scripting.

Verified Solution

The verified solution for using isMemberOf in a client-facing context is to split the work between the server and client. The idea is to have the server evaluate the group membership (since it can use isMemberOf), then pass the result to the client script.

We can achieve this using a display Business Rule and the g_scratchpad object, which is designed to shuttle data from server to client during form load.

Below are the steps for the correct method:

1. Use a Display Business Rule to check group membership

   Create a display business rule on the relevant table (the table of the form you're dealing with). In the business rule's script, use isMemberOf to check the current user's group membership on the server, and store the boolean result in a g_scratchpad variable.

   For example:

// In a Display Business Rule script 
g_scratchpad.isGroupMember = gs.getUser().isMemberOf('YOUR_GROUP_NAME');

This server-side script runs when the form is being loaded and injects the result into g_scratchpad for use on the client. The display business rule ensures that by the time the form and client scripts load, there's a readily available flag indicating the user’s membership status in the specified group.

It's important to note that isMemberOf returns true or false (with true meaning the user is in the group) and that value is what we store.

If you have multiple groups to check, you can add multiple variables to g_scratchpad. For Example:

g_scratchpad.isGroupA = gs.getUser().isMemberOf('Group A');
g_scratchpad.isGroupB = gs.getUser().isMemberOf('Group B');

By planning what info you need ahead of time, you minimize additional server calls once the form is open.

2. Write a client script that uses g_scratchpad for conditional logic

   Next, create an onLoad client script (or incorporate into an existing client script) to use the value set in g_scratchpad. In the client script, you can simply reference the scratchpad variable to determine if the user is a group member and then apply whatever logic is needed on the form.

   For example:

function onLoad() { 
	if (g_scratchpad.isGroupMember) { 
		// User is in the group – allow or show something 
		// e.g., enable a field or show a section
	} else {
		// User is NOT in the group – enforce restrictions
		// e.g., hide certain options or make a field read-only
	} 
}

Using the value from g_scratchpad is straightforward: it's just a JavaScript object available to client scripts on that form. If the scratchpad variable is true, the user belongs to the group, otherwise they do not.

This approach has effectively moved the group check to the server (where it works) and passes a simple flag to the client.

As a quick example scenario, imagine we want to make the State field read-only if the user is not in the "CAB Approval" group.

display business rule:

g_scratchpad.cabApproval = gs.getUser().isMemberOf('CAB Approval'); 

client script:

if (!g_scratchpad.cabApproval) { 
	g_form.setReadOnly('state', true); 
}

Exempting Admins from Restrictions

One crucial detail in our solution is to not unintentionally lock out administrators.

By default, admin users are not automatically members of all groups, so isMemberOf('YOUR_GROUP_NAME') could return false even for an administrator if they aren't explicitly in that group. You likely do not want to restrict an admin’s view or actions, since admins should generally have full access. To address this, adjust your logic to exempt admins from the group check. There are a couple of ways to do this:

• On the server side (in the business rule)

you could set the scratchpad flag to true if the user has the admin role.

For example:

if (gs.hasRole('admin')) {
	g_scratchpad.isGroupMember = true;  // treat admin as member 
} else {
	g_scratchpad.isGroupMember = gs.getUser().isMemberOf('YOUR_GROUP_NAME');
}

This means admins will always get isGroupMember as true, bypassing the restriction.

Alternatively, on the client side, check the admin role via the client-side user object g_user. The g_user.hasRole('admin') method returns true if the user is an admin.

• On the client side (in the client script)

if (g_user.hasRole('admin') || g_scratchpad.isGroupMember) {
	// allow full access (either admin or in group) 
} else {
	// apply restrictions for non-members (excluding admins) 
}

Either approach (or both) will ensure that administrators are not subject to the group-based restrictions. This is a best practice because it prevents scenarios where an admin might unexpectedly see a limited UI due to not formally being in a group. Remember, the admin role grants overarching permissions in ServiceNow, but it does not automatically make the user a member of every group – so we handle that explicitly in our logic.

By following the above steps, you effectively work around the limitation of isMemberOf in client scripts. The server does the membership check (where it's allowed), and the client script simply reads a boolean flag.

This approach is efficient and secure: it avoids additional server calls during client script execution since the information is already available on the form via g_scratchpad. Even though gs.getUser().isMemberOf() isn't available client-side, this method lets you use group membership info on the client seamlessly.

Alternative Solutions

The display business rule and scratchpad method is the most straightforward solution for onLoad scenarios, but there are alternative ways to check group membership from the client side if needed.

The primary alternative is to use GlideAjax with a server-side script (such as a Script Include) to query the user’s group membership on demand.

Using GlideAjax: GlideAjax is a client-callable API that allows you to asynchronously call server code (script include methods) from a client script. Instead of relying on data pre-loaded via g_scratchpad, you can create a Script Include that has a function to check group membership and call that from the client when needed. Here’s how you can implement this:

1. Create a Script Include (Server-side)

   Write a Script Include (which is basically a server-side script library) that has a method to determine if a given user is in a certain group.

   For example:

var UserUtils = Class.create();
UserUtils.prototype = Object.extendsObject(AbstractAjaxProcessor, {
    isUserInGroup: function() {
		//checking current user
        var groupName = this.getParameter('sysparm_group');
        return gs.getUser().isMemberOf(groupName) ? 'true' : 'false';
    }
});

• The Script Include should be callable from client. So set Client callable to true if it's script include class with GlideAjax or use an AJAX processor.

• It should return a clear result like "true" or "false" or a JSON with the info.

2. Call GlideAjax from Client Script

   In your client script, instantiate a GlideAjax object and call the Script Include method. For example:

var ga = new GlideAjax('UserUtils'); 
ga.addParam('sysparm_name', 'isUserInGroup');   ga.addParam('sysparm_group', 'YOUR_GROUP_NAME');
ga.getXMLAnswer(function(answer) {
	if (answer === 'true') {
		// user is a member, proceed accordingly
	} else {
		// user is not a member, apply restrictions
	}
});

• In this snippet, getXMLAnswer is used to asynchronously get the response (which our script include would return as a string "true" or "false"). We then execute the appropriate logic inside the callback once we have the answer.

Advantages and Considerations of GlideAjax

Using GlideAjax is a bit more complex than the scratchpad approach because it involves asynchronous calls and creating a separate script include, but it has its own advantages. It is ideal in scenarios where you might need to check group membership after the form has loaded or based on some user interaction (not just on form load).

For instance, maybe upon changing a field or clicking a button, you want to validate if the user is in a certain group – you could trigger a GlideAjax call at that moment rather than always loading that info upfront. GlideAjax is also useful if you need to check membership for a user other than the current user (you can pass a different user ID to your script include).

It’s worth noting that GlideAjax calls do incur a performance cost (each call is a round trip to the server), so they should be used judiciously.

In many cases, if you know you'll need the group info as soon as the form loads, the scratchpad method is more efficient (one server query during load, rather than an extra AJAX call later).

The ServiceNow best practice is to minimize server lookups from the client side and to prefer asynchronous methods like GlideAjax or scratchpad over client-side GlideRecord queries. In fact, avoid using g_form.getReference() or client GlideRecord queries for checking group membership – those can be inefficient and are not recommended when an asynchronous or scratchpad solution is available.

In summary, GlideAjax provides a flexible alternative for group membership checks on the client side. It requires a bit more setup (script include + client call), but it's the go-to solution for on-demand or complex scenarios where using a display business rule isn't feasible. Both GlideAjax and g_scratchpad are effective tools for retrieving server data in client scripts, and they align with ServiceNow's recommended practices for client-side data access.

Conclusion

Checking a user's group membership in ServiceNow client scripts requires understanding the separation between server and client operations.

The gs.getUser().isMemberOf() function is server-side only, which is why using it directly in client scripts is a pitfall to avoid.

Instead, use the verified approaches discussed:

• Display Business Rule and g_scratchpad

  Pre-calculate the group membership on the server as the form loads, and pass a boolean flag to the client. This method is quick and runs before the form is rendered, making the data immediately available for use in client scripts or UI policies.

  It’s perfect for scenarios where you know you'll need that info upfront (e.g., to conditionally hide or modify form elements as soon as the user sees the form).

  Always remember to account for admin users in this logic so that admins aren't unintentionally restricted.

• GlideAjax and Script Include

  When you need a more dynamic check or want to validate group membership based on user action (or for a different user record), GlideAjax is your friend.

  It allows a client script to call server code asynchronously and get the answer back.

  This keeps the client script lightweight and avoids embedding any confidential logic on the client.

  Just ensure to handle the asynchronous nature (use callbacks or promises) so your code waits for the server response before proceeding.

  
  

Key takeaways and best practices

• Always perform user group validation on the server side, and send only the needed results to the client.

  This approach not only bypasses the limitation of isMemberOf in client scripts but also keeps your instance secure (since group membership logic stays on the server where it cannot be tampered with by end-users).

• Plan ahead by using display business rules for data you'll need immediately on form load, and use GlideAjax for any additional checks after load.

• Test your logic with different user roles – including admin – to ensure that those with elevated permissions are not blocked by group checks (unless that is explicitly desired).

By following these practices, you can confidently implement ServiceNow client scripts that respond to a user's group membership, all while using supported methods and maintaining optimal performance and security.