BigCommerce Checkout: Solving the Mystery of Disappearing Custom Form Fields

In the fast-paced world of e-commerce, a seamless customer experience is paramount. For BigCommerce store owners, this means ensuring every step of the buyer's journey, especially the critical checkout phase, is smooth and error-free. However, a common and frustrating issue can sometimes disrupt this flow: custom form fields that mysteriously clear their content, leaving customers bewildered and potentially abandoning their carts.

A recent discussion in the BigCommerce community highlighted this precise challenge, focusing on a custom VAT number input field where customers found their entered data vanishing, particularly on the checkout page. This seemingly minor glitch can have significant implications for conversion rates and customer satisfaction.

The Vanishing VAT Number: A BigCommerce Checkout Conundrum

The problem, as reported by Jamie Henville, involved a custom VAT number field where customer input would disappear. The store's developer suspected a JavaScript issue within their Stencil theme, potentially exacerbated by specific browsers like Google Chrome. This raised critical questions: Was it a platform bug, a theme conflict, or something else entirely?

The field was a custom addition within the address section, a common requirement for B2B BigCommerce stores. The fact that it was a custom field immediately pointed towards potential interactions with other scripts or browser behaviors not designed for standard BigCommerce fields.

Uncovering the Root Cause: Beyond Browser Autofill

Tanner Brodhagen from Brod Solutions, a seasoned BigCommerce Partner, initially suspected a browser autofill issue – a frequent culprit when custom fields behave unexpectedly. Browsers often try to be 'helpful' by automatically populating fields, sometimes overwriting user input or failing to recognize non-standard fields correctly.

However, upon reviewing the affected checkout page, Tanner made a crucial discovery: a custom checkout script was actively converting the VAT number input to "GB" (Great Britain), forcing it to match the VAT Country. This script was inadvertently clearing or overwriting the user’s input, leading to the frustrating "disappearing act." This pinpointed the problem directly to a custom script interfering with user input, rather than a generic autofill or a platform bug.

Why Custom Fields Disappear: The Three Main Culprits on BigCommerce

As Sajid Jameel from Codinative.com further elaborated, form fields clearing their content on BigCommerce checkouts is almost always caused by one of these three things:

• 1. A JavaScript Conflict in the Checkout: A script running on the page (for validation, analytics, etc.) might be triggering an unintended re-render or reset of the form element, wiping out customer input. This is common in browsers like Chrome due to how they handle form events.
• 2. Browser Autofill Interference: Browsers attempt to autofill fields, sometimes overwriting user input or failing to recognize custom fields correctly, leading to unpredictable behavior.
• 3. A Custom Checkout Script Conflict: As seen in Jamie's case, scripts added to your checkout.html to handle address formatting, VAT validation, or country detection can inadvertently clear or overwrite custom fields as a side effect. The script might standardize input or dynamically update fields, but without careful handling, it can reset manual entries.

Given the context, the most likely culprits were indeed JavaScript conflicts or custom script conflicts. The BigCommerce checkout, especially the optimized one-page checkout, is a complex environment where multiple scripts interact, requiring meticulous attention for any custom modifications.

Implementing the Fix: A Targeted Development Approach

The solution involves reviewing and adjusting the JavaScript running on your BigCommerce checkout page, specifically within the checkout.html file or any scripts injected into it. This is a targeted code adjustment, not a theme rebuild.

How to Approach the Fix:

1. Identify the Conflicting Script: Use browser developer tools to inspect DOM changes and set breakpoints on the input field's change or input events to pinpoint the script modifying its value.
2. Review checkout.html Customizations: Access your theme files (via WebDAV or the control panel for Stencil themes). Look for custom scripts within checkout.html or linked JavaScript files that interact with form fields related to address, country, or VAT.
3. Adjust the Logic: Modify the conflicting script to prevent it from clearing or overwriting the VAT field after a user has entered a value. This often involves:
   • Conditional Logic: Adding an if statement to check if the field already has a value before attempting to modify it. For example:

     if (vatField.value === '' || vatField.value === 'GB') {
         // Only apply default or clear logic if field is empty or has default 'GB'
         vatField.value = newCalculatedValue;
     }

   • Protecting User Input: Prioritizing user-entered data over script-generated defaults.
4. Thorough Testing: After implementing the fix, test extensively across different browsers and devices to ensure the VAT field retains its content and overall checkout functionality remains intact.

Preventative Measures and Big Migration's Expertise

To avoid similar issues, BigCommerce store owners should always:

• Vet Custom Scripts Carefully: Thoroughly test any third-party or custom JavaScript added to the checkout for conflicts.
• Prioritize Stencil Best Practices: Adhere to BigCommerce's Stencil theme development guidelines.
• Regularly Audit Customizations: Update custom scripts as themes and platform features evolve.
• Partner with BigCommerce Experts: For complex customizations or migrations, engaging a certified BigCommerce Partner like Big Migration ensures robust, efficient development.

At Big Migration, we specialize in helping businesses navigate the complexities of e-commerce, from seamless platform migrations to intricate custom development and integrations on BigCommerce. Issues like disappearing form fields, while seemingly small, can significantly impact your bottom line. Our team of experts understands the nuances of the BigCommerce platform, enabling us to diagnose and resolve such challenges efficiently.

Conclusion

The mystery of disappearing form fields on BigCommerce checkout pages is a common, yet fixable, issue. It often boils down to specific JavaScript conflicts, particularly with custom scripts interacting with non-standard fields. By understanding the underlying causes and applying targeted development fixes, BigCommerce store owners can ensure a smooth, reliable, and conversion-friendly checkout experience for all their customers.

Don't let minor technical glitches deter your customers. If you're facing similar challenges or planning a complex BigCommerce migration or customization, reach out to Big Migration. We're here to ensure your e-commerce platform performs flawlessly.