Hi, i've run in the same problem. my goal is to show some images with a redirect link on homepage.

my class:

<?php
class CustomImage extends DataObject 
{
	//db fields
 	static $db = array (
        'Description' => 'Varchar(100)',
    );
    
	/**
	 * Our custom image class contains one image that is used on one page.
	 */
	public static $has_one = array (
		'SliderImage' => 'Image',
		'PageRedirect' => 'SiteTree'
	);

	/**
	 * Popup for editing a single image.
	 *
	 * @return FieldSet The iframe for editing the image.
	 */
	public function getCMSFields_forPopup(){
		$fields = new FieldSet(
			new TextField('Description'),
			new SimpleTreeDropDownField('PageRedirectID','Bild verlinkt zu','SiteTree'),
			new FileIFrameField('SliderImage','Bild für den Slider', Null, Null, Null, 'Uploads/homepage-sliderbilder/')
		);
		return $fields;
	}	
}

and my model:

class HomePage extends Page {
   static $db = array(
   		'HomeMainHeading' => 'Text',
   		'HomeSubHeading' => 'Text',
   		'HomeCol1' => 'HTMLText',
   		'HomeCol2' => 'HTMLText'
   );
 
   	public static $has_many = array(
      	'CustomImages' => 'CustomImage',
	);
   
   function getCMSFields() {
		$fields = parent::getCMSFields();
		
		//SliderImages
		$images = new ImageDataObjectManager(
        	$this, // Controller 
        	'CustomImages', // Source name 
        	'CustomImage', // Source class 
        	'SliderImage', // File name on DataObject 
        	array(
            'Description' => 'Description' //,
           // 'PageRedirect' => 'PageRedirect'
         	), // Headings
         'getCMSFields_forPopup' // Detail fields
         // Filter clause
         // Sort clause
         // Join clause
     	 ); 	
		...	
		$fields->addFieldToTab('Root.Content.SliderBilder', $images);
		return $fields;
	}
}

if i comment out the PageRedirect in the array there is an error (…the method 'fortemplate' does not exist on…). otherwise the SimpleTreeDropDownField is not shown in the popup. Whats wrong with this code?

Thanks for your help. Pipifix

Hello.

I'm still searching a solution for that. So i will appreciate your help. If i change the the PageRedirect in PageRedirectID in the ImageDataObjectManager the dropdown is also not shown. Maybe someone can give me a tip or point me to the error?

Thanks Pipifix