Zend Framework Structure for Datamapper, Controller and Model

There are quite a few questions here and most of the answers will be down largely to personal preference. With that caveat out of the way:

Should everything what is in the Item Database Table be in 1 Model?

I would say yes, although in general, try and think about it from the perspective of the models rather than the database structure. So all of the 'item' data goes in the Item model - the fact that this is all stored in one database table is irrelevant, since the mapper handles the translation from one to the other.

Is it correct that I save the Information about the Image in the Item Mapper?

It's not clear where $imageData comes from in your example, but I'd say the Item mapper should call the Image mapper if there is image data to save, e.g.:

public function save(Application_Model_Item $item)
{
    $data = array(
        'item_title'        => $item->getItemTitle(),
        'item_description'  => $item->getItemDescription(),
    );
    $this->getDbTable()->insert($data);

    // save image data if present
    if (isset($item->image)) {
        $imageMapper = new Yourapp_Mapper_Image();
        $imageMapper->save($item->image);
    }

    return true;
}

[Should] all the Functions like getCounties () stay in the Controller or should it be moved to the GeolocationMapper? And if so, how would that be called up?

I don't see any reason for these functions to be in the controller. Depending on how comfortable you are with the Zend_Form component, one approach might be to write a custom Yourapp_Form_Element_Counties class that extends Zend_Form_Element_Select. You then move your logic from the getCounties function into the this class, so the form element itself is responsible for populating the options it presents. E.g.:

class Yourapp_Form_Element_Counties extends Zend_Form_Element_Select
{
    public function getMultiOptions()
    {
        // load counties here and return an array in the format key -> value
    }
}

Another approach, if you have a lot of location-related form elements, might be to create a GeoLocation Service class, which has a function for counties, cities etc. that returns the options.

Should the Form be created in some Function so I would only call up something like createForm()

It's not clear how much form stuff you are doing in the controller already apart from populating select options, so it's hard to answer this one. Here are the principles I generally follow when using Zend_Form:

• Each form has its own class, extending Zend_Form (or Zend_Dojo_Form), which exists in application/forms and is named Myapp_Form_*
• Each form class sets up its elements in the init() method (which is called automatically by Zend_Form's constructor for exactly this purpose).
• If I find I need slight variations to the same form in different actions (e.g. in an add and edit action), I create an abstract base class for the form (e.g. Myapp_Form_Post_Base) which defines the elements, and then action-specific classes which extend it: Myapp_Form_Post_Add, Myapp_Form_Post_Edit and so on. These classes make any changes they need to the base form in their own init() method.

My actions then look something like this:

public function editAction()
{
    $form = new Myapp_Form_Post_Edit();

    if ($this->_request->isPost()) {
        if ($form->isValid($this->_request->getPost()) {
            // save data, set flash messge and redirect
        }
    }

    $this->view->form = $form;
}

My only other piece of advice is to try and follow the approach which seems most logical to you. You might find it difficult to find definitive 'best practices' for a lot of this stuff since there are many different ways to do it all.

I have tried to follow your ideas as much as possible, so all the calls for the Counties, Towns and Postcodes are in the GeolocationMapper and the saving of the Image Data is in the ImageMapper.

You asked of how I create my Form right now, here an example from my init() of the Form for the Counties etc...

  // Create Dropdown for Counties          
    $county = new Zend_Form_Element_Select('county');      
    $county->setLabel('Select a County')
           ->setRegisterInArrayValidator(false) 
       ->setDecorators(array(
        'ViewHelper',
        'Errors',
              array('Description', 
                      array('tag' => 'p', 'class'=>'description')),         
                    'Label',
              array('HtmlTag',
              array('tag'=>'li','class'=>'county'))                 
             ))  
           ->setRequired(false);

    // Create Dropdown for Town
    $town = new Zend_Form_Element_Select('town');
    $town->setRegisterInArrayValidator(false)
         ->setDecorators(array(
                            'ViewHelper',
                            'Errors',
                            array('Description', array('tag' => 'p', 'class' => 'description')),
                            'Label',
                            array('HtmlTag',array('tag'=>'li','class'=>'town'))
                            ));  


    // Create Dropdown for Postcode
    $postcode = new Zend_Form_Element_Select('postcode');
    $postcode->setRegisterInArrayValidator(false)
             ->setDecorators(array(
                            'ViewHelper',
                            'Errors',
                            array('Description', array('tag' => 'p', 'class' => 'description')),
                            'Label',
                            array('HtmlTag',array('tag'=>'li','class'=>'postcode'))
                            )) 
             ->setRegisterInArrayValidator(false);

In my Controller I than get the Elements and fill them:

$geolocationMapper = new Application_Model_GeolocationMapper();
$CountyOptions = $geolocationMapper->createCountyDropdown();
$form->getElement('county')->setMultiOptions($CountyOptions);

In my GeolocationMapper I have the Methods to build my Array of Counties:

/** ===========================================================================
* Get Counties
* @param 
* @return Object? of Counties  
* ========================================================================= */   

public function getCountyList()
{
        $table = $this->getDbTable();

        $select = $table->select()->distinct()
                  ->from(array('p' => 'geolocation'),'county')
                  ->order('county');
        $resultSet = $this->getDbTable()->fetchAll($select);
        $entries   = array();
        foreach ($resultSet as $row)
        {
            $entry = new Application_Model_Geolocation();
            $entry->setId($row->county)
                  ->setCounty($row->county);   
            $entries[] = $entry;
        }
        return $entries;    
}     



/** ===========================================================================
* Create Array which will be used for Dropdown
* @param 
* @return Array of Counties  
* ========================================================================= */   

public function createCountyDropdown()
{

    // List of Counties does not exist in Cache, read from DB
    if(!$CountyList = $this->getFromCache('counties'))
    {               
        $CountyList = $this->getCountyList();
        $Counties[''] = "Please choose";

        foreach($CountyList as $value)
        {
             $Counties[str_replace(' ','_',$value->getCounty())] = $value->getCounty();
        }

        $CountyDropdown = $Counties;

        // Save DB Result in Cache
        $this->addToCache ('counties',$CountyDropdown);
        return $CountyDropdown;

    }else{
        return $this->getFromCache('counties');     
    }

}

The Counties I read in my GeolocationMapper. The Towns and Postcodes get read when you choose a County, which than calls via Ajax the Geolocation Mapper and than createTownDropdown($county) and when a Town is choosen the same procedure but an Ajax call for loadPostcodes() and there createPostcodeDropdown($town).

Does this all sounds correct or any suggestions how I could improve this?

I am sorry but I would really like to add another question since I can't find an answer anywhere... I also have an Image Upload which works via Ajax and jQuery. When you choose an Image to upload, the Image gets straight displayed. For this I create dynamically an input Element with an image src. I have not found ny other way to add Images otherwise to Zend Form. Is there a possibility to add an Image to display the image as a normal ? It would be just a lot easier to have a img, since I would like to use jQuery Drag and Drop. Thanks so much for your help so far !!!