layout.php

<?php
$params = Astroid\Framework::getTemplate()->getParams();
$template_layout = $params->get('template_layout', 'wide');
if ($template_layout != 'boxed') return false;

$layout_background_image = $params->get('layout_background_image', '');

if (!empty($layout_background_image)) {
    $style = new Astroid\Helper\Style('body');
    $style->addCss('background-image', 'url(' . \JURI::root() . Astroid\Helper\Media::getPath() . '/' . $layout_background_image . ')');
    $style->addCss('background-repeat', $params->get('layout_background_repeat', 'inherit'));
    $style->addCss('background-size', $params->get('layout_background_size', 'inherit'));
    $style->addCss('background-position', $params->get('layout_background_position', 'inherit'));
    $style->addCss('background-attachment', $params->get('layout_background_attachment', 'inherit'));
    $style->render();
}