In this new post to DZone.com today Giorgio Sironi looks at what he considers one of the more valuable yet underestimated components of the Zend Framework - Zend_Validate.

Zend_Validate is a component of Zend Framework which provides validation classes which out-of-the-box enable you to check from string lengths to stranger properties like conformance to regular expressions or to a standard for barcodes. [...] Some parts of Zend_Validate are quite complex, and tie-in with the other components: there are file-related validations on size, hash and more to attach to your forms; in the domain-specific category instead, we can find validator for credit card numbers consistency, or barcodes; isbn codes; and more...

He includes a code sample to show of just some of the validators the component includes like: alpha-numeric, "between", valid email address, valid IP address, matches a regular expression and, a very handy feature of the component, setting up chains of validations.