class VideoHolder extends Page {

static $has_many = array(
'VideoObjects' => 'VideoObject'
);

public function getCMSFields()
{
$fields = parent::getCMSFields();
$datamanager = new DataObjectManager(
$this, // Controller
'VideoObjects', // Source name
'VideoObject', // Source class
array(
'Category' => 'Category',
'Description' => 'Description',
'YouTubeLink' => 'YouTubeLink',
'URLSegment' => 'URLSegment'
), // Headings
'getCMSFields_forPopup'// Detail fields (function name or FieldSet object)
// Filter clause
// Sort clause
// Join clause
);
//$datamanager->setPopupWidth('675');

$fields->addFieldToTab("Root.Content.Videos",$datamanager);
return $fields;
}

}

class VideoObject extends DataObject {

static $db = array (
'Category' => "Enum('Auto Load and Unload, Cappers, DeCappers, Fillers, Leak Detection, Robotics, Washers', 'Auto Load and Unload')",
'Description' => 'Varchar(255)',
'YouTubeLink' => 'Varchar(255)',
'ShortCode' => 'HTMLText',
'URLSegment' => 'Varchar(255)'
);

static $has_one = array(
'VideoHolder' => 'VideoHolder'
);

public function getCMSFields_forPopup()
{
return new FieldSet(
new DropdownField(
$name = "Category",
$title = "Video Category",
$source = singleton('VideoObject')->dbObject('Category')->enumValues()
),
new TextField('Description','Description (text appears in link)'),
new TextField('YouTubeLink','URL of YouTube Page')
);
}

public function onBeforeWrite()
{
if($this->Description){
$this->URLSegment = SiteTree::GenerateURLSegment($this->Description);
if($object = DataObject::get_one($this->ClassName, "URLSegment='" .$this->URLSegment
."' AND ID !=".$this->ID)){
$this->URLSegment = $this->URLSegment.'-'.$this->ID;
}
// else {
//$this->URLSegment = SiteTree::GenerateURLSegment($this->ClassName.'-'.$this->ID);
//}
}
if($this->YouTubeLink){
$this->ShortCode = '[YouTube id="'.substr($this->YouTubeLink,strpos($this->YouTubeLink,"watch?v=")+8,strlen($this->YouTubeLink)).'"]';
}

parent::onBeforeWrite();
}

function ShowActionLink(){
if($this->VideoHolder()){
return $this->VideoHolder()->Link().'show/'.$this->URLSegment;
}
}

}

class Testimonial extends DataObject
{
   static $db = array (
      'Quote' => 'Text',
      'Author' => 'Text'
   );
   
   static $has_one = array (
      'Page' => 'Page'
   );
   
   public function getCMSFields_forPopup()
   {
      return new FieldSet(
         new TextField('Quote', "Quote (no punctuation)"),
         new TextField('Author', "Author name")
      );
   }
   
}

class Page extends SiteTree {
...

   static $has_many = array (
      'Testimonials' => 'Testimonial'
   );   

...
   $TestimonialDataManager = new DataObjectManager(
      $this, // Controller
      'Testimonials', // Source name
      'Testimonial', // Source class
      array(
         "Quote" => "Quote",
         "Author" => "Author name"
      ), // Headings
      'getCMSFields_forPopup' // Detail fields function or FieldSet
      // Filter clause
      // Sort clause
      // Join clause
      );
      $fields->addFieldToTab("Root.Content.Testimonials", $TestimonialDataManager);