3. Building View Components
3.1 Overview
This chapter focuses on the task of building the View components of the application, which will primarily
be created using available presentation technologies. In particular, Phrame provides support for building
applications, as well as for interacting with input forms.
3.2 Automatic Form Validation
Phrame offers an additional facility to validate the input fields it has received. To utilize this feature,
override the following method in your ActionForm class:
<?php
class ValidatingForm extends ActionForm
{
function validate()
{
if (!$this->get('value')) {
trigger_error('Enter some value');
}
}
}
?>
The validate() method is called by the controller after the form properties have been populated, but before
the corresponding action class's perform() method is invoked. The validate() method has the following options:
- Perform the appropriate validations and find no problems -- proceed to call the perform() method of the
appropriate Action class.
- Perform the appropriate validations and find problems -- trigger errors. The controller will store these
and forward control back to the input form (identified by the input property for this ActionMapping).
As mentioned earlier, this feature is entirely optional. The default implementation of the validate() method
does nothing, and the controller will assume that any required validation is done by the action class.
One common approach is to perform simple, prima facia validations using the ActionForm validate() method (or
client-side javascript), and then handle the "business logic" validation from the Action.
Next: Building Controller Components
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Software Development