core-bundle/src/Resources/contao/classes/StyleSheets.php
public function updateStyleSheets()
	{
		$objStyleSheets = $this->Database->execute("SELECT * FROM tl_style_sheet");
		$arrStyleSheets = $objStyleSheets->fetchEach('name');

		// Make sure the dcaconfig.php file is loaded
		if (file_exists($this->strRootDir . '/system/config/dcaconfig.php'))
		{
			@trigger_error('Using the dcaconfig.php file has been deprecated and will no longer work in Contao 5.0. Create one or more DCA files in app/Resources/contao/dca instead.', E_USER_DEPRECATED);
			include $this->strRootDir . '/system/config/dcaconfig.php';
		}

		// Delete old style sheets
		foreach (scan($this->strRootDir . '/assets/css', true) as $file)
		{
			// Skip directories
			if (is_dir($this->strRootDir . '/assets/css/' . $file))
			{
				continue;
			}

			// Preserve root files (is this still required now that scripts are in assets/css/scripts?)
			if (\is_array(Config::get('rootFiles')) && \in_array($file, Config::get('rootFiles')))
			{
				continue;
			}

			// Do not delete the combined files (see #3605)
			if (preg_match('/^[a-f0-9]{12}\.css$/', $file))
			{
				continue;
			}

			$objFile = new File('assets/css/' . $file);

			// Delete the old style sheet
			if ($objFile->extension == 'css' && !\in_array($objFile->filename, $arrStyleSheets))
			{
				$objFile->delete();
			}
		}

		$objStyleSheets->reset();

		// Create the new style sheets
		while ($objStyleSheets->next())
		{
			$this->writeStyleSheet($objStyleSheets->row());
			$this->log('Generated style sheet "' . $objStyleSheets->name . '.css"', __METHOD__, TL_CRON);
		}
	}
public function updateStyleSheets()
	{
		$objStyleSheets = $this->Database->execute("SELECT * FROM tl_style_sheet");
		$arrStyleSheets = $objStyleSheets->fetchEach('name');

		// Make sure the dcaconfig.php file is loaded
		if (file_exists($this->strRootDir . '/system/config/dcaconfig.php'))
		{
			@trigger_error('Using the dcaconfig.php file has been deprecated and will no longer work in Contao 5.0. Create one or more DCA files in app/Resources/contao/dca instead.', E_USER_DEPRECATED);
			include $this->strRootDir . '/system/config/dcaconfig.php';
		}

		// Delete old style sheets
		foreach (scan($this->strRootDir . '/assets/css', true) as $file)
		{
			// Skip directories
			if (is_dir($this->strRootDir . '/assets/css/' . $file))
			{
				continue;
			}

			// Preserve root files (is this still required now that scripts are in assets/css/scripts?)
			if (\is_array(Config::get('rootFiles')) && \in_array($file, Config::get('rootFiles')))
			{
				continue;
			}

			// Do not delete the combined files (see #3605)
			if (preg_match('/^[a-f0-9]{12}\.css$/', $file))
			{
				continue;
			}

			$objFile = new File('assets/css/' . $file);

			// Delete the old style sheet
			if ($objFile->extension == 'css' && !\in_array($objFile->filename, $arrStyleSheets))
			{
				$objFile->delete();
			}
		}

		$objStyleSheets->reset();

		// Create the new style sheets
		while ($objStyleSheets->next())
		{
			$this->writeStyleSheet($objStyleSheets->row());
			$this->log('Generated style sheet "' . $objStyleSheets->name . '.css"', __METHOD__, TL_CRON);
		}
	}
Update all style sheets in the scripts folder