Jim Plush is back with a third part of his look at rethinking models in Zend Framework applications (part one, part two), this time focusing on validation rules.

I've gone ahead and added validation to our test project. If you take a look at the indexController you'll now see I've added an updateAction that uses a Zend Form component. The goal of the validation was to provide context sensitive validation on a model.

He's set up a system that allows you to add "validators" to the model to define how it should handle itself. A later call to "isValid" uses this context to see how it should be evaluated.