Example of how to provide a BackendLayoutFileProvider in TYPO3 6.2

backendlayout.ts

backend_layout {
	colCount = 1
	rowCount = 1
	rows {
		1 {
			columns {
				1 {
					name = Disabled
				}
			}
		}
	}
}

BackendLayoutFileProvider.php

<?php
namespace sunzinet\Typo3szBase\Provider;

/***************************************************************
 *  Copyright notice
 *
 *  (c) 2014 Armin Rüdiger Vieweg <[email protected]>
 *
 *  All rights reserved
 *
 *  This script is part of the TYPO3 project. The TYPO3 project is
 *  free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  The GNU General Public License can be found at
 *  http://www.gnu.org/copyleft/gpl.html.
 *
 *  This script is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  This copyright notice MUST APPEAR in all copies of the script!
 ***************************************************************/

use TYPO3\CMS\Backend\View\BackendLayout\BackendLayout;
use TYPO3\CMS\Backend\View\BackendLayout\BackendLayoutCollection;
use TYPO3\CMS\Backend\View\BackendLayout\DataProviderContext;
use TYPO3\CMS\Core\Utility\GeneralUtility;

/**
 * Class FileProvider
 */
class BackendLayoutFileProvider implements \TYPO3\CMS\Backend\View\BackendLayout\DataProviderInterface {

	/**
	 * Adds backend layouts to the given backend layout collection.
	 *
	 * @param DataProviderContext $dataProviderContext
	 * @param BackendLayoutCollection $backendLayoutCollection
	 * @return void
	 */
	public function addBackendLayouts(DataProviderContext $dataProviderContext, BackendLayoutCollection $backendLayoutCollection) {
		$files = $this->getLayoutFiles();
		foreach ($files as $file) {
			$backendLayout = $this->createBackendLayout($file);
			$backendLayoutCollection->add($backendLayout);
		}
	}

	/**
	 * Gets a backend layout by (regular) identifier.
	 *
	 * @param string $identifier
	 * @param integer $pageId
	 * @return BackendLayout|NULL test
	 */
	public function getBackendLayout($identifier, $pageId) {
		$files = $this->getLayoutFiles();
		foreach ($files as $file) {
			$fileInformation = pathinfo($file);
			if ($identifier === array_pop(explode(DIRECTORY_SEPARATOR, $fileInformation['dirname']))) {
				return $this->createBackendLayout($file);
			}
		}
		return NULL;
	}

	/**
	 * Returns backend layout paths
	 *
	 * @return array
	 */
	protected function getLayoutFiles() {
		$fileCollection = array();

		if (!isset($GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['BackendLayoutFileProvider'])
				|| !is_array($GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['BackendLayoutFileProvider'])) {
			return $fileCollection;
		}

		if (is_array($GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['BackendLayoutFileProvider']['dir'])) {
			foreach ($GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['BackendLayoutFileProvider']['dir'] as $directory) {
				$directory = GeneralUtility::getFileAbsFileName($directory);
				$subDirectories = GeneralUtility::get_dirs($directory);
				if (is_array($subDirectories)) {
					foreach ($subDirectories as $subDirectory) {
						$layoutFile = $directory . DIRECTORY_SEPARATOR . $subDirectory . DIRECTORY_SEPARATOR . 'backendlayout.ts';
						if (file_exists($layoutFile)) {
							$this->addFileToCollection($layoutFile, $fileCollection);
						}
					}
				}
			}
		}
		return $fileCollection;
	}

	/**
	 * Creates a new backend layout using the given record data.
	 *
	 * @param string $file
	 * @return BackendLayout
	 */
	protected function createBackendLayout($file) {
		$fileInformation = pathinfo($file);

		$backendLayout = BackendLayout::create(
			array_pop(explode(DIRECTORY_SEPARATOR, $fileInformation['dirname'])),
			$this->getTitle($fileInformation),
			GeneralUtility::getUrl($file)
		);
		return $backendLayout;
	}

	/**
	 * @param $file
	 * @param $fileCollection
	 * @return void
	 * @throws \UnexpectedValueException
	 */
	protected function addFileToCollection($file, array &$fileCollection) {
		$key = sha1($file);
		if (isset($fileCollection[$key])) {
			throw new \UnexpectedValueException(sprintf('The file "%s" exists already, see "%s"', $file, $fileCollection[$key]));
		}
		$fileCollection[$key] = $file;
	}


	/**
	 * Returns title of backend_layout located in locallang.xml. If key or file
	 * is not existing, the directory name of backend_layout will be returned
	 *
	 * @param array $fileInformation pathinfo() information of the given file
	 * @return string
	 */
	protected function getTitle(array $fileInformation) {
		$locallangFile = $fileInformation['dirname'] . DIRECTORY_SEPARATOR . 'locallang.xml';
		if (file_exists($locallangFile)) {
			$title = $GLOBALS['LANG']->sL('LLL:' . $locallangFile . ':title');
			if (!empty($title)) {
				return $title;
			}
		}
		return array_pop(explode(DIRECTORY_SEPARATOR, $locallangFile));
	}
}

ext_localconf.php

<?php

if (TYPO3_MODE === 'BE') {
		// Provide file based backend layouts
	$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['BackendLayoutDataProvider']['typo3sz_base']
		= 'sunzinet\Typo3szBase\Provider\BackendLayoutFileProvider';

		// Here you set the path of backend layouts
	$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['BackendLayoutFileProvider']['dir'][]
	= 'fileadmin/templates/data/backend_layouts';
}

// Folder structure of previously set path of backend layouts:
// 
// fileadmin/templates/data/backend_layouts/
// 	- main
//		- backendlayout.ts
//		- locallang.xml
//	- main-right
//		- backendlayout.ts
//		- locallang.xml

// "main" and "main-right" are the names of the provided backend layouts.
// The backendlayout.ts contains the configuration of the layout.
// The locallang.xml some one translation for the title of the layout in backend.

locallang.xml

<?xml version="1.0" encoding="utf-8" standalone="yes" ?>
<T3locallang>
	<meta type="array">
		<type>database</type>
		<description>Language labels for backend layouts</description>
	</meta>
	<data type="array">
		<languageKey index="default" type="array">
			<label index="title">Main-Template</label>
		</languageKey>
		<languageKey index="de" type="array">
			<label index="title">Haupt-Template</label>
		</languageKey>
	</data>
</T3locallang>