My Submission for the Silverstripe Code Competition

MarketPlaceProduct.php

<?php
/**
 * Code submitted by Lamin Barrow (@laminbarrow)
 */
class MarketPlaceProduct extends BaseProduct
{
    private static $db = array(
        'AdditionalDetails' => 'MultiValueField',
    );

    private static $has_one = array(
        'Owner' => 'Member',
    );

    private static $dependencies = array(
        'marketPlacePaymentService' => '%$MarketPlacePaymentService',
    );

    public function getCMSFields()
    {
        $fields = parent::getCMSFields();
        $fields->push(KeyValueField::create('AdditionalDetails', 'Additional Details (Key and Value)'));
        return $fields;
    }

    public function buy()
    {
        return $this->marketPlacePaymentService->buy($this);
    }

    public function sell()
    {
        return $this->marketPlacePaymentService->sell($this);
    }

    public function processRender(SS_HTTPRequest $request)
    {
        if ($marketPlaceProduct = MarketPlaceProduct::get()->byID($request->param('ID'))) {
            if (Director::is_Ajax()) {
                return $marketPlaceProduct->renderWith('MarketPlaceProduct');
            }

            return $marketPlaceProduct->renderWith('MarketPlaceProduct', 'Page');
        }
        return ErrorPage::response_for(404);
    }
}