PHP 7 Programming Cookbook

Tying validation to a form

When a form is first rendered, there is little value in having a form class (such as Application\Form\Factory, described in the previous recipe) tied to a class that can perform filtering or validation (such as the Application\Filter\* described in the previous recipe). Once the form data has been submitted, however, interest grows. If the form data fails validation, the values can be filtered, and then re-displayed. Validation error messages can be tied to form elements, and rendered next to form fields.

How to do it...

1. First of all, be sure to implement the classes defined in the Implementing a Form Factory, Chaining $_POST Filters, and Chaining $_POST Validators recipes.
2. We will now turn our attention to the Application\Form\Factory ...