Attachment.php

<?php
App::uses('MediaAppModel', 'Media.Model');
App::uses('Folder', 'Utility');
App::uses('File', 'Utility');

/**
 * Attachment Model
 *
 */
class Attachment extends MediaAppModel {

/**
 * Display field
 *
 * @var string
 */
	public $displayField = 'name';

/**
 * Behaviors
 *
 * @var array
 */
	public $actsAs = array(
		'Media.Uploadable' => array( 'filename' )
	);

/**
 * Validation rules
 *
 * @var array
 */
	public $validate = array(
		'name' => array(
			'notEmpty' => array(
				'rule' => array('notEmpty'),
				//'message' => 'Your custom message here',
				//'allowEmpty' => false,
				//'required' => false,
				//'last' => false, // Stop validation after this rule
				//'on' => 'create', // Limit validation to 'create' or 'update' operations
			),
		),
		'filename' => array(
			'uploadError' => array(
				'rule' => array('uploadError')
			),
		),
		'mimetype' => array(
			'notEmpty' => array(
				'rule' => array('notEmpty'),
				//'message' => 'Your custom message here',
				//'allowEmpty' => false,
				//'required' => false,
				//'last' => false, // Stop validation after this rule
				//'on' => 'create', // Limit validation to 'create' or 'update' operations
			),
		),
	);

	public function afterFind( $results, $primary = false ) {

		die('afterFind');


		foreach ( $results as $index => $result ) {

			if( !empty( $result[$this->alias] ) ) {
				$path = Folder::slashTerm(Configure::read('Media.uploadDir')) . $result[$this->alias]['directory'] . $result[$this->alias]['filename'];

				$url = MediaThumbnail::getUrl($path);

				$results[$index] = Hash::merge($results[$index], array($this->alias => array(
					'path' => $path,
					'url' => $url,
				)));
			}
		}

		return $results;
	}

}

QuestionsController.php

<?php

/**
 * form method
 *
 * Responsible for rendering the form template for add and edit views.
 *
 * @return void
 */
	private function form() {

		// create some empty answers if there are none
		if( empty($this->request->data['Answer']) ){
			$this->request->data['Answer'] = array_fill(0, 3, array(
				'Answer' => array('id' => '', 'required' => '', 'content' => ''),
				'AnswerOption' => array (
					array('id' => '', 'content' => '', 'attachment_id' => ''),
				)
			));
		}

		// ne need to get the attachments for all the AnswerOptions
		$this->request->data['Answer'] = Hash::map($this->request->data['Answer'], '{n}', function( $answer ){

			$answer['AnswerOption'] = Hash::map($answer['AnswerOption'], '{n}', function( $answerOption ){

				if( empty($answerOption['Attachment']) && !empty($answerOption['attachment_id']) ){

					$attachment =  $this->Question->Answer->AnswerOption->Attachment->find('first', array(
						'conditions' => array('Attachment.id' => $answerOption['attachment_id'])
					));

					$answerOption = array_merge($answerOption, $attachment);
				}

				return $answerOption;

			});

			return $answer;
		});

		echo '<pre>';
		print_r($this->request->data);

		die();
		// reset the answer array keys to prevent clashes when adding/removing
		$this->request->data['Answer'] = array_values($this->request->data['Answer']);

		// create some empty options
		/*$this->request->data['Answer'] = Hash::map($this->request->data['Answer'], "{n}", function( $item ){
			$item['AnswerOption'] = array_values($item['AnswerOption']);
			return $item;
		});*/

		$this->render('_form');
	}