title: Zend Form addFilter StripTags not stripping tags
body: <p>I need a little help clearing something up with Zend_Form and adding filters to an element.  Now I was under the impression that when you add a filter to the form that, when the form is posted that filter was executed as part of dispatch in the controller.</p>
  
  <p>However when testing my form to my horror the filter <em>StripTags</em> doesn't seem to be running and I am getting the data with the HTML tags in the data.</p>
  
  <p>My Form element looks like this.</p>
  
  <pre><code>$address1 = new Zend_Form_Element_Textarea('address1');
      $address1-&gt;addFilter('StripTags')
          -&gt;addFilter('StringTrim')            
          -&gt;setAttrib('cols', 30)
          -&gt;setAttrib('rows', 5)
          -&gt;removeDecorator('DtDdWrapper')
          -&gt;removeDecorator('label')
          -&gt;removeDecorator('HtmlTag')
  </code></pre>
  
  <p>However if I put in the text area the some data with html tags in it and then check the form is valid using </p>
  
  <pre><code>$formData = $this-&gt;_request-&gt;getPost();
  if($form-&gt;isValid($formData){
      ...
  </code></pre>
  
  <p>The data comes back with the tags in it.  It only removed when I pass the data through the <strong>strip_tags()</strong> function.</p>
  
  <p>I suppose my question is should the <em>StipTags</em> filter if so why isn't it?  What am I missing here. </p>