BackendConfigurationManager->getCurrentPageId()

BackendConfigurationManager.php

<?php
	/**
	 * Returns the page uid of the current page.
	 * If no page is selected, we'll return the uid of the first root page.
	 *
	 * @return integer current page id. If no page is selected current root page id is returned
	 */
	protected function getCurrentPageId() {
		$pageId = (integer) \TYPO3\CMS\Core\Utility\GeneralUtility::_GP('id');
		if ($pageId > 0) {
			return $pageId;
		}
		// get current site root
		$rootPages = $GLOBALS['TYPO3_DB']->exec_SELECTgetRows('uid', 'pages', 'deleted=0 AND hidden=0 AND is_siteroot=1', '', '', '1');
		if (count($rootPages) > 0) {
			return $rootPages[0]['uid'];
		}
		// get root template
		$rootTemplates = $GLOBALS['TYPO3_DB']->exec_SELECTgetRows('pid', 'sys_template', 'deleted=0 AND hidden=0 AND root=1', '', '', '1');
		if (count($rootTemplates) > 0) {
			return $rootTemplates[0]['pid'];
		}
		// fallback
		return self::DEFAULT_BACKEND_STORAGE_PID;
	}
?>