This gem will use ActiveRecord’s existing validates_format#presence#uniqueness_of method to check whether the email parameter has a valid format, is present and is unique

Advanced ActiveModel email validation with MX lookups, domain blacklisting and disposable email blocking

A simple, localizable EachValidator for email address fields in ActiveRecord 3.0.

Ruby Library for the mailboxlayer API, a web service that email validation & verification, https://mailboxlayer.com/

Add state maps to Rails Enums for validation on transitions.

error_messages_for_helper provides a simple helper to show ActiveRecord validation errors (just like old helper error_messages_for for Rails-2.3.x).

ElasticSearch Queries, gem that allows elastic creation of complex ES queries, and end up in hashes. Validation enabled. Uses eapi gem)

LiveValidation integration with default Rails form helpers and validation methods.

100% exclusive message for any ActiveModel validation error.

= dm-is-published This plugin makes it very easy to add different states to your models, like 'draft' vs 'live'. By default it also adds validations of the field value. Originally inspired by the Rails plugin +acts_as_publishable+ by <b>fr.ivolo.us</b>. == Installation # Add G...

This is a module for the Ruby language that defines a callback GEDCOM parser. It does not do any validation of a GEDCOM file, but, using application-defined callback hooks, can traverse any well-formed GEDCOM.

Gem for simplify display of validation messages and flash.

Local Apple receipt validation.

Forms with ActiveModel-like validations

ActiveRecord::MySQL::Strict adds validations to ActiveRecord models to make sure they do not trigger errors in MySQL strict mode.

Interdependent model validations

UPS address validation gem

Calls and parses various maps APIs for accurate address validation and geocoding

Array validations for Rails (e.g. Postgres jsonb columns)

Object validation library