[fw-general] Problem with Zend_Form and filters (ZF 1.6.2)

[Ralf Eggert]

Hi,

I have this short form class:

-------------------------------------------------------------------------
  class Form_PizzaCreate extends Zend_Form
  {
      public function init()
      {
          // lege Attribute für Formular fest
          $this->setAction('/pizza/create');

          // erstelle Formularelement für Pizza Name
          $pizzaName = new Zend_Form_Element_Text('name');

          // füge zwei Filterobjekte hinzu
          $pizzaName->addFilter('Zend_Filter_Alpha');
      }
  }
-------------------------------------------------------------------------

When I try to initialize this form I get the following error:

-------------------------------------------------------------------------
Fatal error: Uncaught exception 'Zend_Loader_PluginLoader_Exception'
with message 'Plugin by name Zend_Filter_Alpha was not found in the
registry.' in
/home/devhost/zfbuch/ZendFramework-1.6.2/library/Zend/Loader/PluginLoader.php:370
Stack trace: #0
/home/devhost/zfbuch/ZendFramework-1.6.2/library/Zend/Form/Element.php(1937):
Zend_Loader_PluginLoader->load('Zend_Filter_Alp...') #1
/home/devhost/zfbuch/ZendFramework-1.6.2/library/Zend/Form/Element.php(1613):
Zend_Form_Element->_loadFilter(Array) #2
/home/devhost/zfbuch/ZendFramework-1.6.2/library/Zend/Form/Element.php(524):
Zend_Form_Element->getFilters() #3
/home/devhost/zfbuch/ZendFramework-1.6.2/library/Zend/Form/Element.php(541):
Zend_Form_Element->_filterValue(NULL, NULL) #4
/home/devhost/zfbuch/ZendFramework-1.6.2/library/Zend/Form/Decorator/ViewHelper.php(201):
Zend_Form_Element->getValue() #5
/home/devhost/zfbuch/ZendFramework-1.6.2/library/Zend/Form/Decorator/ViewHelper.php(231):
Zend_Form_Decorator_ViewHelper->getValue(Object(Zend_Form_Element_Text))
#6 /home/devh in
/home/devhost/zfbuch/ZendFramework-1.6.2/library/Zend/Loader/PluginLoader.php
on line 370
-------------------------------------------------------------------------

When I use
  $pizzaName->addFilter('Alpha')
or
  $pizzaName->addFilter(new Zend_Filter_Alpha())
this error does not occur.

Can anybody reproduce this error? Is this a bug? Or is my system
configured badly?

Thanks for advice.

Best regards,

Ralf