Rails API parameter validation

Uses the power and familiarity of ActiveModel::Validations to validate hash structures. Designed for detecting and providing feedback on bad requests to your RESTful Web Service.

Postgresql constraints in migrations similiar to ActiveRecord validations

pure ruby PNG file manipulation & validation

This gem allows you to create use cases with ActiveModel validations and keep your model clean

Settler can be used for defining application wide settings in Rails. Settings are loaded from a YAML file and stored in the database using ActiveRecord to allow users to update settings on the fly. The YAML configuration allows you to not only specify defaults, but setting value validations and t...

Input Mask validation for ActiveModel

JSON schema validation for Rails

Allows testing vor valid html (including html5) and css. In addition you can configure the gem to use a locally installed validation service instead of the online w3c servers

A library for setting up model validations, such as in ActiveRecord.

When IBAN validation is not enough

Standalone PORO assertions and validations

ActiveModel email validation. Checks MX records, sub address, regex, whitelisted and blacklisted check

GTIN provides basic validation, checksum and conversion functionality for UPC, EAN and GTIN barcode values.

Rails Form Builder supports Client-side validation using jQuery BootstrapValidator plugin. https://github.com/nghuuphuoc/bootstrapvalidator

ActiveRecord Tablefree Models provides a simple mixin for creating models that are not bound to the database. This approach is useful for taking advantage of the features of ActiveRecord such as validation, relationships, nested_attributes, etc.

A library for making it extremely fast for Rails developers to set up and save ActiveRecord instances when writing test cases. It aims to: * meet all your validations automatically * only make you specify the attributes you care about * give you a rich set of features so you can specify associa...

Provides client side validations for forms with the http://formvalidation.io/ library.

Custom Ruby on Rails form builder that generates GOV.UK elements styled markup for form inputs, including error validation messages.

Email Detected is a simple tool for verifying an email address exists. It's free and quite easy to use :smile: .Many times as developers we were putting validation statements for checking email addresses format. This gem will complete your existing setups with validator that actually connects wit...