GlideForm.flashField() — ServiceNow API

g_form.flashField(fieldName, color, count)→ void

advancedTested on Xanadu

What It Does

The flashField method temporarily changes a field's background color in a pulsing animation to draw the user's attention. The field alternates between its normal appearance and the specified color for the designated number of cycles.

Internally, ServiceNow manipulates the field's DOM element by adding and removing CSS background color styles on a timer. Each flash cycle consists of showing the colored background for approximately 250ms, then returning to normal for another 250ms. The entire animation is non-blocking and runs asynchronously.

The method returns void and provides no feedback about success or failure. If the field doesn't exist or isn't visible, the method silently does nothing. There's no way to interrupt a flash sequence once it starts.

The flash effect only works on fields that are currently visible and rendered in the DOM. Reference fields, choice lists, and text inputs all support flashing, but fields hidden by UI policies or ACL restrictions will not flash. The animation respects the field's current state and styling.

Unlike showFieldMsg which displays persistent text messages, flashField provides temporary visual feedback without adding any UI elements. It complements methods like setValue by highlighting when a field's value has been programmatically changed.

When to Use This

Use flashField when you need to draw immediate attention to a specific field after a significant change or validation event. It's particularly effective after auto-populating fields based on user selections, highlighting fields that failed validation, or indicating where important calculations have updated values.

Avoid using flashField for persistent error states where showFieldMsg would be more appropriate. Don't use it on every field change as it becomes annoying and loses impact. Multiple simultaneous flashes can be visually overwhelming and should be used sparingly.

⚠️

Overuse of flashField creates a distracting user experience. Reserve it for truly important notifications that require immediate attention.

Return Value

The method returns void and provides no indication of success or failure. There's no return value to check whether the field exists, is visible, or if the flash animation started successfully.

Since there's no return value, you cannot chain this method or use it in conditional statements. The animation runs asynchronously, so subsequent code executes immediately without waiting for the flash sequence to complete.

Free Newsletter

Enjoying this? Get one deep-dive per week.

Join 1,000+ ServiceNow pros — scripts, GlideRecord patterns, Flow Designer techniques, and career moves. Free.

Platform Behavior & Side Effects

No server-side events fire - this is purely a client-side visual effect
No database writes occur - the field value and record remain unchanged
Performance impact is minimal - uses lightweight CSS animations
Animation cannot be interrupted once started - subsequent calls queue up
Works consistently across different field types (text, choice, reference)
Browser focus and accessibility features remain unaffected by the animation
Mobile interfaces may show reduced animation smoothness depending on device

Parameters

Name	Type	Required	Description
fieldName	string	Yes	The field name to flash. Must be a valid field on the current form that exists in the DOM. Field must be visible to the user for the flash effect to work.
color	string	Yes	Hex color code including the # symbol (e.g., '#FF0000' for red). Invalid hex codes default to red. Bright colors work best for visibility.
count	number	Yes	Number of times to flash the field. Each flash cycle takes approximately 500ms. Values less than 1 result in no flash.

Chrome Extension

Sourdough: ServiceNow Monitoring and Analytics

A Chrome extension for ServiceNow Admins and Developers with essential tools, analytics, graphs and monitoring features.

Instance HealthGraphs & ChartsAPI HealthDeveloper ToolsQuick SearchInstance Switcher

Add to Chrome

Free to install. Pro $5/month after a 14-day no-card trial.
Pro requires the ServiceNow admin role. Upgrade inside the extension.

Overview

Tasks

CMDB

API

Metrics

Monitor

Internals

Instance:sourdoughdev·Version:Yokohama

Instance StateONLINE

System StatusFully Operational

Session Timeout90 minutes

Logged-In Sessions2 (20 active)

Build Nameyokohama-12-18-2024_p1

IP Address10.159.128.43

Instance HealthHealth Score: 90%

🔥 5dSourdough (Chrome Plugin)Dark Mode

Code Examples

Basic field validation feedbackbasic

// Flash priority field red when urgency changes to high
function onChange(control, oldValue, newValue, isLoading) {
    if (isLoading || newValue == '') return;
    
    // Auto-set priority based on urgency
    if (newValue == '1') { // High urgency
        g_form.setValue('priority', '1');
        // Draw attention to the priority change
        g_form.flashField('priority', '#FF4444', 3);
    } else if (newValue == '3') { // Low urgency
        g_form.setValue('priority', '4');
        g_form.flashField('priority', '#4444FF', 2);
    }
}

Shows the most common pattern - flashing a field after programmatically setting its value to help users notice the automated change. The red flash for high priority creates stronger visual emphasis.

Multiple field coordination with timingintermediate

// Calculate and highlight total cost when quantity changes
function onChange(control, oldValue, newValue, isLoading) {
    if (isLoading) return;
    
    var quantity = parseInt(newValue) || 0;
    var unitPrice = parseFloat(g_form.getValue('unit_price')) || 0;
    var total = quantity * unitPrice;
    
    // Update total and flash to show calculation
    g_form.setValue('total_price', total.toFixed(2));
    g_form.flashField('total_price', '#00AA00', 2);
    
    // Flash quantity field if value seems unusually high
    if (quantity > 100) {
        setTimeout(function() {
            g_form.flashField('quantity', '#FF8800', 4);
        }, 1000); // Delay to avoid simultaneous flashes
    }
}

Demonstrates coordinating multiple flash animations with timing delays to avoid visual overload. The setTimeout prevents competing animations and draws sequential attention to related fields.

The classic mistake - flashing hidden fieldsadvanced

// WRONG: Attempting to flash fields that may not be visible
function validateAssignment() {
    var assignedTo = g_form.getValue('assigned_to');
    var assignmentGroup = g_form.getValue('assignment_group');
    
    if (!assignedTo && !assignmentGroup) {
        // This fails silently if fields are hidden by UI policy
        g_form.flashField('assigned_to', '#FF0000', 3);
        g_form.flashField('assignment_group', '#FF0000', 3);
        return false;
    }
}

// RIGHT: Check visibility before flashing
function validateAssignment() {
    var assignedTo = g_form.getValue('assigned_to');
    var assignmentGroup = g_form.getValue('assignment_group');
    
    if (!assignedTo && !assignmentGroup) {
        if (g_form.isVisible('assigned_to'))
            g_form.flashField('assigned_to', '#FF0000', 3);
        if (g_form.isVisible('assignment_group'))
            g_form.flashField('assignment_group', '#FF0000', 3);
        return false;
    }
}

Shows why you must verify field visibility before flashing. Hidden fields silently ignore flash commands, leaving users without the intended visual feedback for validation errors.

Gotchas

Invalid hex color codes default to red without any error indication, making debugging color issues difficult.

Multiple rapid calls to flashField on the same field queue up the animations rather than replacing them, creating unexpectedly long flash sequences.

Fields hidden by UI policies or ACL restrictions silently ignore flash commands with no error feedback.

The flash animation timing is fixed at approximately 500ms per cycle and cannot be customized for faster or slower effects.

Reference field pop-up windows and related lists don't support field flashing even when the parent form field does.

Test Your Knowledge

Quick 3-question quiz — see how your ServiceNow skills stack up.

Question 1 of 3Performance

A list view on a table with millions of records is slow. Best fix?

Select an answer to continue