The Zend Framework blog has continued their series spotlighting various components of the framework with their latest installment. In this latest tutorial they cover the zend-validator component used to validate data against a set of rules for correctness.

In our previous post, we covered zend-filter, The filters in zend-filter are generally used to pre-filter or normalize incoming data. This is all well and good, but we still don't know if the data is valid. That's where zend-validator comes in.

The post starts with showing how to get the component installed via Composer and the optional dependency of the zend-service-manager component (to handle the use of ValidatorChain functionality). Code is included showing the interface the validators all conform to and an example of the validator in use. It then covers some of the built-in validation options and how to build up a validator "chain" of multiple checks. It also shows how to break the validation if one fails, setting priority (order of execution), evaluating values in certain contexts and registering your own custom validators.