AHValidation is an open source and extensible validation library specifically designed for Cocoa Touch development.
AHValidation allows one to add an arbitrary number of arbitrarily defined validation rules to any Cocoa object for the purpose of easily checking object validity and presenting user-friendly error messages.
AHValidation does this by extending the NSObject class to provide methods for manipulating an object's associated collection of validation rules (objects of types deriving from AHValidationRule), along with the validate method, which returns a collection of zero or more messages corresponding to unfulfilled validation rules.
The AHValidation library provides a collection of pre-built rules, including AHStringLengthRule, AHRegexRule, and AHNumericRangeRule for achieving many common validation tasks.
Detailed instructions on how to use the AHValidation Cocoa Touch library are available HERE.
· Apple Xcode