HtmlCompressor.php

<?php
/**
 * HtmlCompressor.php
 * @author Revin Roman
 * @link https://rmrevin.ru
 */

namespace appmake\yii2\minify;

/**
 * Class HtmlCompressor
 * @package rmrevin\yii\minify
 */
class HtmlCompressor
{

	/**
	 * @param string $data is either a handle to an open file, or an HTML string
	 * @param null|array $options key => value array of execute options
	 * The possible keys are:
	 *
	 *  - `c` or `no-comments` - removes HTML comments
	 *  - `s` or `stats` - output filesize savings calculation
	 *  - `x` or `extra` - perform extra (possibly unsafe) compression operations
	 *
	 * Example: HtmlCompressor::compress($HtmlCode, $options = ['no-comments' => true])
	 *
	 * @return string
	 */
	public static function compress($data, $options = null) {
		return (new static)->htmlCompress($data, $options);
	}

	/**
	 * HTML Compressor 1.0.1
	 * Original Author: Tyler Hall <tylerhall@gmail.com>
	 * Edited by: Revin Roman <xgismox@gmail.com>
	 * Latest Source and Bug Tracker: http://github.com/tylerhall/html-compressor
	 *
	 * Attemps to reduce the filesize of an HTML document by removing unnecessary
	 * whitespace at the beginning and end of lines, inside closing tags, and
	 * stripping blank lines completely. <pre> tags are respected and their contents
	 * are left alone. Warning, nested <pre> tags may exhibit unexpected behaviour.
	 *
	 * This code is licensed under the MIT Open Source License.
	 * Copyright (c) 2010 tylerhall@gmail.com
	 * Permission is hereby granted, free of charge, to any person obtaining a copy
	 * of this software and associated documentation files (the "Software"), to deal
	 * in the Software without restriction, including without limitation the rights
	 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	 * copies of the Software, and to permit persons to whom the Software is
	 * furnished to do so, subject to the following conditions:
	 *
	 * The above copyright notice and this permission notice shall be included in
	 * all copies or substantial portions of the Software.
	 *
	 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	 * THE SOFTWARE.
	 *
	 * @param $data
	 * @param null|array $options
	 *
	 * @return bool|mixed|string
	 */
	private function htmlCompress($data, $options = null) {
		if (!isset($options)) {
			$options = [];
		}

		$data .= "\n";
		$out = '';
		$inside_pre = false;
		$bytecount = 0;

		while ($line = $this->getLine($data)) {
			$bytecount += strlen($line);

			if (!$inside_pre) {
				if (strpos($line, '<pre') === false) {
					// Since we're not inside a <pre> block, we can trim both ends of the line
					$line = trim($line);

					// And condense multiple spaces down to one
					$line = preg_replace('/\s\s+/', ' ', $line);
				} else {
					// Only trim the beginning since we just entered a <pre> block...
					$line = ltrim($line);

					// If the <pre> ends on the same line, don't turn on $inside_pre...
					list($line, $inside_pre) = $this->checkInsidePre($line);
				}
			} else {
				list($line, $inside_pre) = $this->checkInsidePre($line);
			}

			// Filter out any blank lines that aren't inside a <pre> block...
			if ($inside_pre) {
				$out .= $line;
			} elseif ($line != '') {
				$out .= $line . "\n";
			}
		}

		// Perform any extra (unsafe) compression techniques...
		if (array_key_exists('x', $options) || array_key_exists('extra', $options)) {
			// Can break layouts that are dependent on whitespace between tags
			$out = str_replace(">\n<", '><', $out);
		}

		// Remove HTML comments...
		if (array_key_exists('c', $options) || array_key_exists('no-comments', $options)) {
			$out = preg_replace('/(<!--.*?-->)/ms', '', $out);
			$out = str_replace('<!>', '', $out);
		}

		// Remove the trailing \n
		$out = trim($out);

		// Output either our stats or the compressed data...
		if (array_key_exists('s', $options) || array_key_exists('stats', $options)) {
			$echo = '';
			$echo .= "Original Size: $bytecount\n";
			$echo .= "Compressed Size: " . strlen($out) . "\n";
			$echo .= "Savings: " . round((1 - strlen($out) / $bytecount) * 100, 2) . "%\n";
			echo $echo;
		} else {
			return $out;
		}

		return false;
	}

	/**
	 * @param $line
	 *
	 * @return array
	 */
	private function checkInsidePre($line) {
		$inside_pre = true;

		if ((strpos($line, '</pre') !== false) && (strripos($line, '</pre') >= strripos($line, '<pre'))) {
			$line = rtrim($line);
			$inside_pre = false;
		}

		return [$line, $inside_pre];
	}

	/**
	 * Returns the next line from an open file handle or a string
	 *
	 * @param $data
	 *
	 * @return bool|string
	 */
	private function getLine(&$data) {
		if (is_resource($data)) {
			return fgets($data);
		}

		if (is_string($data)) {
			if (strlen($data) > 0) {
				$pos = strpos($data, "\n");
				$return = substr($data, 0, $pos) . "\n";
				$data = substr($data, $pos + 1);

				return $return;
			} else {
				return false;
			}
		}

		return false;
	}

	/**
	 * @param $data
	 * @param null|array $options
	 *
	 * @return bool|mixed|string
	 * @deprecated
	 * @codeCoverageIgnore
	 */
	private function html_compress($data, $options = null) {
		return $this->htmlCompress($data, $options);
	}

	/**
	 * Returns the next line from an open file handle or a string
	 *
	 * @param $data
	 *
	 * @return bool|string
	 * @deprecated
	 * @codeCoverageIgnore
	 */
	private function get_line(&$data) {
		\Yii::warning(sprintf('You are using an deprecated method `%s`.', 'get_line'));

		return $this->getLine($data);
	}
}