Have trouble with advanced command line options, software dependency presence validation, handling inputs, confirmations and colorizing? Then this gem is for you. It provides you with some modules you can include to add those specific features.

SimpleForm Plugin for ClientSideValidaitons

This tool provides a one-command setup, configuration and validation for cloud servers.

Hash validation for 'options'-like methods.

Property types that add CHECK constraints to your DB and validations to your model. Data integrity FTW.

Paper-thin Facebook validation and signed request parsing Rails plugin

Gem to remove previously set validations

Adds ActiveModel validation for domain format.

ActiveModel validations for domains with fully localization support.

This gem is part of the Deployment and Orchestration for Puppet or DOP for short. dop_common is a library for the parsing and validation of DOP plan files.

Dr Nic's Magic Models - Invisible validations, assocations and Active Record models themselves!

Mutations gem interface implemented with `dry-rb`’s validation schemas.

Dependency-free object validation library for Ruby 1.8.7+

Reliable contract definition, data validation, and type checking for Ruby.

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).