Instead of scattering validations, strong parameters, and business rules across controllers and models, changesets give you one clear pipeline for handling data before it touches the database.

validate-response is a gem for bringing error messages from one or more ActiveRecord objects to the unified structure & highlight validation errors in forms (ajax supported).

Telephone number validation based on RFC3966

CivilService provides a base class for your service objects. With CivilService, you can use ActiveModel validations to do pre-flight checks before the service runs, and create your own result object classes to capture the results of complex operations.

Dynamic uniqueness validator to validation two fields before save in db.

Parameter validation extension for Sinatra

Call method_contraints! with the param name and constraint to enforce validation on it

A Rails controller concern which makes it easy to encapsulate validation and processing of complex incoming data into command classes.

Adds an abstract EachValidator superclass that you can use to create localizable validations.

Mobile MSISDN detection & validation. Only useful whenever your'e a Mobile Operator 3rd Party and receive MSISDN headers.

Small and extensible data validation toolkit

Hashie2 + ActiveModel 3, offering declared properties, validations, JSON serialization/deserialization

Validate presence/absence of resource creation/update and relationship update payloads, as well as types related resources

Having to validate method parameters and/or the result of method is a quite common and repetitive task. Tchae is an attempt to capture this task in a small yet generic reuseable library. Tchae provides validated variants of the standard define_method ruby methods , that will create the same metho...

Validates polish identification numbers NIP, PESEL, REGON. Can be used in any ruby script or integrated with Rails validation

Provides a OneOfManyValidator for Rails validation. This allows you to validate that one of a set of fields should be required, but no particular field itself is required.

Allows Kumi schemas to be written as plain text with syntax validation and editor integration.

This gem is very fast C++ code for calculating AUCs on results of cross-validation. It is specific to the crossval database schema, which has not been released yet. Chances are you will not find this very useful unless you are the author. It is in gem form to ensure that each lab machine can c...

Validation frontend for models. Inspired by the scrivener gem.

A composable application toolkit, providing data entities and collections, transforms, contract-based validations and pre-built operations. Architecture agnostic for easy integration with other toolkits or frameworks.