A credit card validation library to check offline validity of any AMEX, Discover, MasterCard, Visa cards using length and Luhn algorithm.

A data validation library providing a rule-based schema definition language. For checking (incoming) data against a specified schema definition. GDS stands for General Data Structure.

A simple set of validations I got tired of writing over and over and over again.

Server side validations for ember.js framework, model agnostic

Handles rails validation errors foundation's way

Ajax validation

An ActiveModel extension for more expressive validations reflection

Provides an extensible hook for adding custom html attributes to input elements based on validation rules defined in your model.

Simple validation of params with a concern

generate validations from the schema - used in production with MySQL

A Rails model validation, my first gem, just a practice work

Extra validations for rails: date, domain, email, iban, phone, postal_code, commerce_number, vat_number

Ruby wrapper for Experian Address Validation API

gem for email validation

To comply with simple email validation to RFC5322.

HTML Acceptance lets you accept warnings/errors. Less noisey validation will hopefully let you build html validation into your test suite, but break the rules if you must.

Subvalid allows you to use a familiar syntax to define validator classes to validate plain objects. Rather than hard coding single validation logic into the objects themselves, different validation logic can be used depending on the context.

A simple gem that adds a validate_before method to Thor, allowing pre-command validations

Extract validations from your database information

Module which provides sexy validations for models.