I need froms which supplies CRUD in fronend. No problem to get it working in the backend. I just testetd GenericViews, but it just works for the action view. When i try to customize the url like this

form/8/view to

form/8/edit

i got an empty page. Silverstripe Version is 2.4.5

So i tried out how to make it by my own,
the form Page looks liek this. I tried to get the data after creation back into the form fields.

i save the ID in "createPerson" with Session::set('ID',$submission->ID);

and get it back in myForm with DataObject::get_by_id('HorseSubmission',$id);

is it the right way? How to updated data for an special ID?

class FormPage extends Page {
    static $db = array(
    );

		static $has_one = array(
    );

}
 
class FormPage_Controller extends Page_Controller {
   function myForm() {   	
   			if(Session::get("ID"))
      	{
      		$id = Session::get("ID");
      		$record = DataObject::get_by_id('HorseSubmission',$id);

		      $fields = new FieldSet(
						new TextField('Person','Person',$record->Person),
 						new ImageField('Image1','Bild',$record->Image1),
 						new ImageField('Image2','Bild',$record->Image2),
        	);
         
        	// Create actions
        	$actions = new FieldSet(
            new FormAction('createHorse', 'Submit')
        	);
     
        	return new Form($this, 'myForm', $fields, $actions);
      	}	//end if 
      	else
      	{
        	$fields = new FieldSet(              
						new TextField('Name'),
 						new ImageField('Image1'),
 						new ImageField('Image2')
        	);
         
        $actions = new FieldSet(
            new FormAction('createPerson', 'Submit')
        );
     
        return new Form($this, 'myForm', $fields, $actions);
       } // end else
    }
    
       function createPerson($data, $form) {
                $submission = new PersonSubmission();
                $form->saveInto($submission);
                $submission->write();
                Session::set('ID',$submission->ID);
	        Director::redirectBack();      
       }
}

To update a Person i added a method "updatePerson". It's the same like "createPerson" above. I've just added the line $submission->ID = Session::get("ID");
So it's possible to specify the ID before ->write()

Is this really the way you should solve a CRUD funcionality in SilverStripe?
For me it seems not bad, but really different from other Solutions.
The ID's are stored in OS temp dir, in Silverstripe cache -> Session
Nothing, no Id, no data is visible for the user - correct me i am wrong.

function updatePerson($data, $form) {
        $submission = new PersonSubmission();
        $form->saveInto($submission);
        $submission->ID = Session::get("ID");
        $submission->write();
        Session::set('ID',$submission->ID);
	Director::redirectBack();      
}

Not totally sure I get what you're trying to do, as we'd need to see your actual data object and not just the form. But the easiest way to pass the an ID from a Form to an action is to place it a hidden field. If you're editing an existing submission you can use (using you current method of storing the ID):

$id = Session::get("ID");
$submission = DataObject::get_by_id("PersonSubmission", $id);
$form->saveInto($submission);
$submission->write();

Since the object record already exists you just need to pull it from the DB before saving into. Take a look at this page http://doc.silverstripe.org/sapphire/en/topics/datamodel#update I left out the if statement so you may want to add it back in