Helper to customize the validation messages in Hanami application views.

If you need a way to easily skip validations on some attributes and only in certain cases, this gem will allow you to do it in a clean and elegant way.

A extension activemodel's validations to validation step by step.

Checks whether an ActiveModel Validator is attached to an attribute of a Model and with which options

extension for active_record

Rails 3 generator plugin that generates validator's skeleton files.

Validação de inscrição estadual dos 26 estados federativos

Allow validate uniqueness across multiple column

An implementation of several error checking algorithms,including Luhn and Damm.

contextual validations for controllers and wanna learn to do other stuff good too

ActiveModel validation for credit card number.

As your Rails projects evolve and grow, your model validations tend to change as well. An unfortunate side effect of this evolution is that your table- backed ActiveRecord::Base descendants end up with rows that instantiate invalid model instances. ValidData generates a report for your Rails application, notifying you exactly how many rows in your models are invalid for each model.

Small Gem to validate parameters. Can be integrated with Rails controllers

Extension to ActiveModel for validating hostnames

API Wrapper for Validic

Validate ISO country and Code

Ruby gem to check validity of Estonian ID card or Estonian Passport

valid_syntax checks if a string containing ruby code has any syntax errors. If this is the case, the syntax errors will be stored to be later accessed.

Yet another CSV validator library. Just better.

Valkyrie::MetadataAdapter for Postgres using Sequel.