Top Features of Virto SharePoint Custom Mask Field Web Part

What the Custom Mask Field Web Part Does

Enforces a predefined input pattern (mask) on text fields.
Provides visual cues and placeholders while users type.
Validates input format and can prevent saving invalid data.
Supports common mask tokens (digits, letters, alphanumerics) and custom tokens.
Integrates with SharePoint forms (classic, modern, and some form-building solutions depending on environment and Virto product version).

Key benefit: consistent, validated data entry without requiring custom development.

Setup and Installation

Prerequisites

A supported SharePoint environment (check Virto’s documentation for compatibility with your SharePoint version — SharePoint Online vs. SharePoint Server).
Appropriate permissions to add and configure Web Parts (Site Owner or Site Collection Admin typically).
The Virto Forms / Web Parts package installed or available in the app catalog if using SharePoint Online. For on-premises, access to install the solution package (.wsp or installer) on the farm.

Installation steps (high-level)

Acquire the Virto package that contains the Custom Mask Field Web Part (from Virto Software or your vendor portal).
For SharePoint Online:
- Upload the package to the Tenant App Catalog (if required).
- Add the app to the site where you want to use the web part.
For SharePoint Server (on-premises):
- Deploy the solution to the farm and activate the feature on the target site collections.
Confirm the web part appears in the Web Part gallery (classic) or the list of available web parts/components (modern pages or form editors).
Add the web part to a form or page to begin configuration.

Configuration and Mask Syntax

Common mask tokens

0 — digit (0–9), required.
9 — digit (0–9), optional.
L — letter (A–Z or a–z), required.
? — letter (A–Z or a–z), optional.
A — alphanumeric (letter or digit), required.
a — alphanumeric, optional.
* — any character.
Literal characters (e.g., parentheses, hyphens) appear in the mask and are inserted automatically.

Example masks:

Phone (US): “(000) 000-0000”
Date (ISO-ish): “0000-00-00”
Postal code (5 digits): “00000”
Serial code: “LLL-0000-A” (three letters, hyphen, four digits, hyphen, single letter)

Configuring the mask in the Web Part

Open the page or form where the web part was added and switch to edit mode.
Open the web part properties.
Set the field source (which SharePoint column the mask should apply to) or configure the web part to use its own field.
Enter the mask string using the supported tokens.
Configure placeholder text, whether literals are auto-inserted, and whether incomplete inputs are blocked on save.
Optionally set custom validation error messages and tooltips to guide users.

Use Cases and Examples

Enforcing phone numbers in a directory to a single format for easier parsing and dialing.
Requiring employees to enter national ID numbers in a strict format for HR processes.
Standardizing product or asset tags across a catalog (e.g., “PRD-000-LL”).
Formatting dates or times where control over separators and leading zeros matters.
Integrating with external systems that expect a specific format for import/export.

Example: To ensure UK-style phone numbers (simplified), you might use mask “00000 000000” with a tooltip telling users the country code should be omitted.

Tips for Effective Use

Keep masks as permissive as you can while still meeting data needs. Overly strict masks can frustrate users (e.g., requiring spaces or parentheses exactly where a user doesn’t expect them).
Use optional tokens where variations are allowed (use 9, ?, or a).
Provide example placeholder text and clear inline help so users know what to type.
For international fields (phone numbers, postal codes), consider storing an additional field for country or format type and dynamically apply masks based on that selection.
Combine mask validation with server-side checks where possible; client-side masks improve UX but should not be the only validation.
Test masks with real-world data samples to ensure legitimate variations are accepted.
When integrating with automated imports, strip mask literals on import/export if the external system expects raw digits/letters.

Best Practices

Document the mask format and reasoning in your site or form documentation so maintainers understand the intent.
Use separate columns for raw and formatted values if you need both (store raw for integration, formatted for display).
Consider accessibility: make sure screen readers and keyboard-only users can understand the expected format. Provide accessible helper text and error messages.
For complex conditional masking (different masks based on other field values), implement logic in the form or use Virto features that support dynamic configuration, or fallback to custom code if necessary.
Monitor and adjust: collect examples of rejected inputs to refine masks and reduce false negatives.
Keep backup and versioning of your web part configurations so you can revert if a mask change causes issues.

Troubleshooting

Mask not applying: verify the web part is connected to the correct field/column and that the feature or app is activated on the site.
Validation blocked but input looks correct: check for invisible literals (spaces, non-breaking spaces) and remove them from the mask or input.
Conflicts with other client-side scripts or custom form frameworks: load order or script compatibility can break mask behavior; try disabling other custom scripts or use a development site to isolate conflicts.
Mobile input issues: some mobile keyboards insert different characters or format automatically; test on representative devices and simplify masks when necessary.
Performance concerns: if many masked fields are on the same page, test load times; lazy-load or limit simultaneous masked inputs if needed.

Advanced: Dynamic Masks and Integration

Conditional masks: apply different masks based on another field (e.g., country). Implement by using form logic (Power Apps, custom form scripts) that updates the web part configuration or switches visibility between multiple masked fields.
Data interchange: when exporting to CSV or integrating via APIs, decide whether to export the masked display value or the raw unmasked value. Use workflow or calculated fields to produce the desired export format.
Custom tokens: if Virto supports custom tokens, define tokens for project-specific needs (e.g., check digits). Otherwise, consider preprocessing inputs with scripts before final save.

Security and Compliance Considerations

Masks help with data quality but not with data protection. For sensitive fields (SSNs, passport numbers), ensure proper access controls, encryption at rest, and retention policies.
Avoid exposing full sensitive values in UI where not necessary — consider masked display with reveal-on-demand for authorized users.
Log changes and validation failures for audit purposes where compliance requires traceability.

Example: Step-by-step—Add Masked Phone Field to a Contact List

Add the Virto Custom Mask Field Web Part to the contact list form.
In web part properties, select the phone number column.
Enter mask: “(000) 000-0000”.
Enable auto-insertion of literals and set the placeholder to “(123) 456-7890”.
Set validation to prevent save if incomplete and add an error message: “Enter a valid 10-digit phone number.”
Test by creating and editing a contact; verify the field auto-formats and blocks invalid saves.

When Not to Use a Mask

When input formats are highly variable (e.g., international postal addresses) better to validate with flexible rules or use helper parsing rather than strict masks.
When users frequently paste preformatted values that include unexpected literals—masks can interfere with natural paste behavior.
For free-text fields where semantic content matters more than format.

Final Thoughts

The Virto SharePoint Custom Mask Field Web Part is a powerful, low-code way to improve data quality and user experience in SharePoint forms. Use clear, tested masks, provide helpful guidance to users, and combine client-side masks with server-side validation and governance for robust results. With thoughtful application—especially for internationalization and accessibility—you can standardize inputs without creating friction.