Mercurial > hg > rc2
diff program/lib/Roundcube/rcube_html2text.php @ 0:4681f974d28b
vanilla 1.3.3 distro, I hope
| author | Charlie Root |
|---|---|
| date | Thu, 04 Jan 2018 15:52:31 -0500 |
| parents | |
| children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/program/lib/Roundcube/rcube_html2text.php Thu Jan 04 15:52:31 2018 -0500 @@ -0,0 +1,722 @@ +<?php + +/** + +-----------------------------------------------------------------------+ + | This file is part of the Roundcube Webmail client | + | Copyright (C) 2008-2012, The Roundcube Dev Team | + | Copyright (c) 2005-2007, Jon Abernathy <jon@chuggnutt.com> | + | | + | Licensed under the GNU General Public License version 3 or | + | any later version with exceptions for skins & plugins. | + | See the README file for a full license statement. | + | | + | PURPOSE: | + | Converts HTML to formatted plain text (based on html2text class) | + +-----------------------------------------------------------------------+ + | Author: Thomas Bruederli <roundcube@gmail.com> | + | Author: Aleksander Machniak <alec@alec.pl> | + | Author: Jon Abernathy <jon@chuggnutt.com> | + +-----------------------------------------------------------------------+ + */ + +/** + * Takes HTML and converts it to formatted, plain text. + * + * Thanks to Alexander Krug (http://www.krugar.de/) to pointing out and + * correcting an error in the regexp search array. Fixed 7/30/03. + * + * Updated set_html() function's file reading mechanism, 9/25/03. + * + * Thanks to Joss Sanglier (http://www.dancingbear.co.uk/) for adding + * several more HTML entity codes to the $search and $replace arrays. + * Updated 11/7/03. + * + * Thanks to Darius Kasperavicius (http://www.dar.dar.lt/) for + * suggesting the addition of $allowed_tags and its supporting function + * (which I slightly modified). Updated 3/12/04. + * + * Thanks to Justin Dearing for pointing out that a replacement for the + * <TH> tag was missing, and suggesting an appropriate fix. + * Updated 8/25/04. + * + * Thanks to Mathieu Collas (http://www.myefarm.com/) for finding a + * display/formatting bug in the _build_link_list() function: email + * readers would show the left bracket and number ("[1") as part of the + * rendered email address. + * Updated 12/16/04. + * + * Thanks to Wojciech Bajon (http://histeria.pl/) for submitting code + * to handle relative links, which I hadn't considered. I modified his + * code a bit to handle normal HTTP links and MAILTO links. Also for + * suggesting three additional HTML entity codes to search for. + * Updated 03/02/05. + * + * Thanks to Jacob Chandler for pointing out another link condition + * for the _build_link_list() function: "https". + * Updated 04/06/05. + * + * Thanks to Marc Bertrand (http://www.dresdensky.com/) for + * suggesting a revision to the word wrapping functionality; if you + * specify a $width of 0 or less, word wrapping will be ignored. + * Updated 11/02/06. + * + * *** Big housecleaning updates below: + * + * Thanks to Colin Brown (http://www.sparkdriver.co.uk/) for + * suggesting the fix to handle </li> and blank lines (whitespace). + * Christian Basedau (http://www.movetheweb.de/) also suggested the + * blank lines fix. + * + * Special thanks to Marcus Bointon (http://www.synchromedia.co.uk/), + * Christian Basedau, Norbert Laposa (http://ln5.co.uk/), + * Bas van de Weijer, and Marijn van Butselaar + * for pointing out my glaring error in the <th> handling. Marcus also + * supplied a host of fixes. + * + * Thanks to Jeffrey Silverman (http://www.newtnotes.com/) for pointing + * out that extra spaces should be compressed--a problem addressed with + * Marcus Bointon's fixes but that I had not yet incorporated. + * + * Thanks to Daniel Schledermann (http://www.typoconsult.dk/) for + * suggesting a valuable fix with <a> tag handling. + * + * Thanks to Wojciech Bajon (again!) for suggesting fixes and additions, + * including the <a> tag handling that Daniel Schledermann pointed + * out but that I had not yet incorporated. I haven't (yet) + * incorporated all of Wojciech's changes, though I may at some + * future time. + * + * *** End of the housecleaning updates. Updated 08/08/07. + */ + +/** + * Converts HTML to formatted plain text + * + * @package Framework + * @subpackage Utils + */ +class rcube_html2text +{ + /** + * Contains the HTML content to convert. + * + * @var string $html + */ + protected $html; + + /** + * Contains the converted, formatted text. + * + * @var string $text + */ + protected $text; + + /** + * Maximum width of the formatted text, in columns. + * + * Set this value to 0 (or less) to ignore word wrapping + * and not constrain text to a fixed-width column. + * + * @var integer $width + */ + protected $width = 70; + + /** + * Target character encoding for output text + * + * @var string $charset + */ + protected $charset = 'UTF-8'; + + /** + * List of preg* regular expression patterns to search for, + * used in conjunction with $replace. + * + * @var array $search + * @see $replace + */ + protected $search = array( + '/\r/', // Non-legal carriage return + '/^.*<body[^>]*>\n*/is', // Anything before <body> + '/<head[^>]*>.*?<\/head>/is', // <head> + '/<script[^>]*>.*?<\/script>/is', // <script> + '/<style[^>]*>.*?<\/style>/is', // <style> + '/[\n\t]+/', // Newlines and tabs + '/<p[^>]*>/i', // <p> + '/<\/p>[\s\n\t]*<div[^>]*>/i', // </p> before <div> + '/<br[^>]*>[\s\n\t]*<div[^>]*>/i', // <br> before <div> + '/<br[^>]*>\s*/i', // <br> + '/<i[^>]*>(.*?)<\/i>/i', // <i> + '/<em[^>]*>(.*?)<\/em>/i', // <em> + '/(<ul[^>]*>|<\/ul>)/i', // <ul> and </ul> + '/(<ol[^>]*>|<\/ol>)/i', // <ol> and </ol> + '/<li[^>]*>(.*?)<\/li>/i', // <li> and </li> + '/<li[^>]*>/i', // <li> + '/<hr[^>]*>/i', // <hr> + '/<div[^>]*>/i', // <div> + '/(<table[^>]*>|<\/table>)/i', // <table> and </table> + '/(<tr[^>]*>|<\/tr>)/i', // <tr> and </tr> + '/<td[^>]*>(.*?)<\/td>/i', // <td> and </td> + ); + + /** + * List of pattern replacements corresponding to patterns searched. + * + * @var array $replace + * @see $search + */ + protected $replace = array( + '', // Non-legal carriage return + '', // Anything before <body> + '', // <head> + '', // <script> + '', // <style> + ' ', // Newlines and tabs + "\n\n", // <p> + "\n<div>", // </p> before <div> + '<div>', // <br> before <div> + "\n", // <br> + '_\\1_', // <i> + '_\\1_', // <em> + "\n\n", // <ul> and </ul> + "\n\n", // <ol> and </ol> + "\t* \\1\n", // <li> and </li> + "\n\t* ", // <li> + "\n-------------------------\n", // <hr> + "<div>\n", // <div> + "\n\n", // <table> and </table> + "\n", // <tr> and </tr> + "\t\t\\1\n", // <td> and </td> + ); + + /** + * List of preg* regular expression patterns to search for, + * used in conjunction with $ent_replace. + * + * @var array $ent_search + * @see $ent_replace + */ + protected $ent_search = array( + '/&(nbsp|#160);/i', // Non-breaking space + '/&(quot|rdquo|ldquo|#8220|#8221|#147|#148);/i', + // Double quotes + '/&(apos|rsquo|lsquo|#8216|#8217);/i', // Single quotes + '/>/i', // Greater-than + '/</i', // Less-than + '/&(copy|#169);/i', // Copyright + '/&(trade|#8482|#153);/i', // Trademark + '/&(reg|#174);/i', // Registered + '/&(mdash|#151|#8212);/i', // mdash + '/&(ndash|minus|#8211|#8722);/i', // ndash + '/&(bull|#149|#8226);/i', // Bullet + '/&(pound|#163);/i', // Pound sign + '/&(euro|#8364);/i', // Euro sign + '/&(amp|#38);/i', // Ampersand: see _converter() + '/[ ]{2,}/', // Runs of spaces, post-handling + ); + + /** + * List of pattern replacements corresponding to patterns searched. + * + * @var array $ent_replace + * @see $ent_search + */ + protected $ent_replace = array( + "\xC2\xA0", // Non-breaking space + '"', // Double quotes + "'", // Single quotes + '>', + '<', + '(c)', + '(tm)', + '(R)', + '--', + '-', + '*', + '£', + 'EUR', // Euro sign. € + '|+|amp|+|', // Ampersand: see _converter() + ' ', // Runs of spaces, post-handling + ); + + /** + * List of preg* regular expression patterns to search for + * and replace using callback function. + * + * @var array $callback_search + */ + protected $callback_search = array( + '/<(a) [^>]*href=("|\')([^"\']+)\2[^>]*>(.*?)<\/a>/i', // <a href=""> + '/<(h)[123456]( [^>]*)?>(.*?)<\/h[123456]>/i', // h1 - h6 + '/<(b)( [^>]*)?>(.*?)<\/b>/i', // <b> + '/<(strong)( [^>]*)?>(.*?)<\/strong>/i', // <strong> + '/<(th)( [^>]*)?>(.*?)<\/th>/i', // <th> and </th> + ); + + /** + * List of preg* regular expression patterns to search for in PRE body, + * used in conjunction with $pre_replace. + * + * @var array $pre_search + * @see $pre_replace + */ + protected $pre_search = array( + "/\n/", + "/\t/", + '/ /', + '/<pre[^>]*>/', + '/<\/pre>/' + ); + + /** + * List of pattern replacements corresponding to patterns searched for PRE body. + * + * @var array $pre_replace + * @see $pre_search + */ + protected $pre_replace = array( + '<br>', + ' ', + ' ', + '', + '' + ); + + /** + * Contains a list of HTML tags to allow in the resulting text. + * + * @var string $allowed_tags + * @see set_allowed_tags() + */ + protected $allowed_tags = ''; + + /** + * Contains the base URL that relative links should resolve to. + * + * @var string $url + */ + protected $url; + + /** + * Indicates whether content in the $html variable has been converted yet. + * + * @var boolean $_converted + * @see $html, $text + */ + protected $_converted = false; + + /** + * Contains URL addresses from links to be rendered in plain text. + * + * @var array $_link_list + * @see _build_link_list() + */ + protected $_link_list = array(); + + /** + * Boolean flag, true if a table of link URLs should be listed after the text. + * + * @var boolean $_do_links + * @see __construct() + */ + protected $_do_links = true; + + /** + * Constructor. + * + * If the HTML source string (or file) is supplied, the class + * will instantiate with that source propagated, all that has + * to be done it to call get_text(). + * + * @param string $source HTML content + * @param boolean $from_file Indicates $source is a file to pull content from + * @param boolean $do_links Indicate whether a table of link URLs is desired + * @param integer $width Maximum width of the formatted text, 0 for no limit + */ + function __construct($source = '', $from_file = false, $do_links = true, $width = 75, $charset = 'UTF-8') + { + if (!empty($source)) { + $this->set_html($source, $from_file); + } + + $this->set_base_url(); + + $this->_do_links = $do_links; + $this->width = $width; + $this->charset = $charset; + } + + /** + * Loads source HTML into memory, either from $source string or a file. + * + * @param string $source HTML content + * @param boolean $from_file Indicates $source is a file to pull content from + */ + function set_html($source, $from_file = false) + { + if ($from_file && file_exists($source)) { + $this->html = file_get_contents($source); + } + else { + $this->html = $source; + } + + $this->_converted = false; + } + + /** + * Returns the text, converted from HTML. + * + * @return string Plain text + */ + function get_text() + { + if (!$this->_converted) { + $this->_convert(); + } + + return $this->text; + } + + /** + * Prints the text, converted from HTML. + */ + function print_text() + { + print $this->get_text(); + } + + /** + * Sets the allowed HTML tags to pass through to the resulting text. + * + * Tags should be in the form "<p>", with no corresponding closing tag. + */ + function set_allowed_tags($allowed_tags = '') + { + if (!empty($allowed_tags)) { + $this->allowed_tags = $allowed_tags; + } + } + + /** + * Sets a base URL to handle relative links. + */ + function set_base_url($url = '') + { + if (empty($url)) { + if (!empty($_SERVER['HTTP_HOST'])) { + $this->url = 'http://' . $_SERVER['HTTP_HOST']; + } + else { + $this->url = ''; + } + } + else { + // Strip any trailing slashes for consistency (relative + // URLs may already start with a slash like "/file.html") + if (substr($url, -1) == '/') { + $url = substr($url, 0, -1); + } + $this->url = $url; + } + } + + /** + * Workhorse function that does actual conversion (calls _converter() method). + */ + protected function _convert() + { + // Variables used for building the link list + $this->_link_list = array(); + + $text = $this->html; + + // Convert HTML to TXT + $this->_converter($text); + + // Add link list + if (!empty($this->_link_list)) { + $text .= "\n\nLinks:\n------\n"; + foreach ($this->_link_list as $idx => $url) { + $text .= '[' . ($idx+1) . '] ' . $url . "\n"; + } + } + + $this->text = $text; + $this->_converted = true; + } + + /** + * Workhorse function that does actual conversion. + * + * First performs custom tag replacement specified by $search and + * $replace arrays. Then strips any remaining HTML tags, reduces whitespace + * and newlines to a readable format, and word wraps the text to + * $width characters. + * + * @param string &$text Reference to HTML content string + */ + protected function _converter(&$text) + { + // Convert <BLOCKQUOTE> (before PRE!) + $this->_convert_blockquotes($text); + + // Convert <PRE> + $this->_convert_pre($text); + + // Run our defined tags search-and-replace + $text = preg_replace($this->search, $this->replace, $text); + + // Run our defined tags search-and-replace with callback + $text = preg_replace_callback($this->callback_search, array($this, 'tags_preg_callback'), $text); + + // Strip any other HTML tags + $text = strip_tags($text, $this->allowed_tags); + + // Run our defined entities/characters search-and-replace + $text = preg_replace($this->ent_search, $this->ent_replace, $text); + + // Replace known html entities + $text = html_entity_decode($text, ENT_QUOTES, $this->charset); + + // Replace unicode nbsp to regular spaces + $text = preg_replace('/\xC2\xA0/', ' ', $text); + + // Remove unknown/unhandled entities (this cannot be done in search-and-replace block) + $text = preg_replace('/&([a-zA-Z0-9]{2,6}|#[0-9]{2,4});/', '', $text); + + // Convert "|+|amp|+|" into "&", need to be done after handling of unknown entities + // This properly handles situation of "&quot;" in input string + $text = str_replace('|+|amp|+|', '&', $text); + + // Bring down number of empty lines to 2 max + $text = preg_replace("/\n\s+\n/", "\n\n", $text); + $text = preg_replace("/[\n]{3,}/", "\n\n", $text); + + // remove leading empty lines (can be produced by eg. P tag on the beginning) + $text = ltrim($text, "\n"); + + // Wrap the text to a readable format + // for PHP versions >= 4.0.2. Default width is 75 + // If width is 0 or less, don't wrap the text. + if ( $this->width > 0 ) { + $text = wordwrap($text, $this->width); + } + } + + /** + * Helper function called by preg_replace() on link replacement. + * + * Maintains an internal list of links to be displayed at the end of the + * text, with numeric indices to the original point in the text they + * appeared. Also makes an effort at identifying and handling absolute + * and relative links. + * + * @param string $link URL of the link + * @param string $display Part of the text to associate number with + */ + protected function _build_link_list($link, $display) + { + if (!$this->_do_links || empty($link)) { + return $display; + } + + // Ignored link types + if (preg_match('!^(javascript:|mailto:|#)!i', $link)) { + return $display; + } + + // skip links with href == content (#1490434) + if ($link === $display) { + return $display; + } + + if (preg_match('!^([a-z][a-z0-9.+-]+:)!i', $link)) { + $url = $link; + } + else { + $url = $this->url; + if (substr($link, 0, 1) != '/') { + $url .= '/'; + } + $url .= "$link"; + } + + if (($index = array_search($url, $this->_link_list)) === false) { + $index = count($this->_link_list); + $this->_link_list[] = $url; + } + + return $display . ' [' . ($index+1) . ']'; + } + + /** + * Helper function for PRE body conversion. + * + * @param string &$text HTML content + */ + protected function _convert_pre(&$text) + { + // get the content of PRE element + while (preg_match('/<pre[^>]*>(.*)<\/pre>/ismU', $text, $matches)) { + $this->pre_content = $matches[1]; + + // Run our defined tags search-and-replace with callback + $this->pre_content = preg_replace_callback($this->callback_search, + array($this, 'tags_preg_callback'), $this->pre_content); + + // convert the content + $this->pre_content = sprintf('<div><br>%s<br></div>', + preg_replace($this->pre_search, $this->pre_replace, $this->pre_content)); + + // replace the content (use callback because content can contain $0 variable) + $text = preg_replace_callback('/<pre[^>]*>.*<\/pre>/ismU', + array($this, 'pre_preg_callback'), $text, 1); + + // free memory + $this->pre_content = ''; + } + } + + /** + * Helper function for BLOCKQUOTE body conversion. + * + * @param string &$text HTML content + */ + protected function _convert_blockquotes(&$text) + { + $level = 0; + $offset = 0; + while (($start = stripos($text, '<blockquote', $offset)) !== false) { + $offset = $start + 12; + do { + $end = stripos($text, '</blockquote>', $offset); + $next = stripos($text, '<blockquote', $offset); + + // nested <blockquote>, skip + if ($next !== false && $next < $end) { + $offset = $next + 12; + $level++; + } + // nested </blockquote> tag + if ($end !== false && $level > 0) { + $offset = $end + 12; + $level--; + } + // found matching end tag + else if ($end !== false && $level == 0) { + $taglen = strpos($text, '>', $start) - $start; + $startpos = $start + $taglen + 1; + + // get blockquote content + $body = trim(substr($text, $startpos, $end - $startpos)); + + // adjust text wrapping width + $p_width = $this->width; + if ($this->width > 0) $this->width -= 2; + + // replace content with inner blockquotes + $this->_converter($body); + + // resore text width + $this->width = $p_width; + + // Add citation markers and create <pre> block + $body = preg_replace_callback('/((?:^|\n)>*)([^\n]*)/', array($this, 'blockquote_citation_callback'), trim($body)); + $body = '<pre>' . htmlspecialchars($body) . '</pre>'; + + $text = substr_replace($text, $body . "\n", $start, $end + 13 - $start); + $offset = 0; + + break; + } + // abort on invalid tag structure (e.g. no closing tag found) + else { + break; + } + } + while ($end || $next); + } + } + + /** + * Callback function to correctly add citation markers for blockquote contents + */ + public function blockquote_citation_callback($m) + { + $line = ltrim($m[2]); + $space = $line[0] == '>' ? '' : ' '; + + return $m[1] . '>' . $space . $line; + } + + /** + * Callback function for preg_replace_callback use. + * + * @param array $matches PREG matches + * @return string + */ + public function tags_preg_callback($matches) + { + switch (strtolower($matches[1])) { + case 'b': + case 'strong': + return $this->_toupper($matches[3]); + case 'th': + return $this->_toupper("\t\t". $matches[3] ."\n"); + case 'h': + return $this->_toupper("\n\n". $matches[3] ."\n\n"); + case 'a': + // Remove spaces in URL (#1487805) + $url = str_replace(' ', '', $matches[3]); + return $this->_build_link_list($url, $matches[4]); + } + } + + /** + * Callback function for preg_replace_callback use in PRE content handler. + * + * @param array $matches PREG matches + * @return string + */ + public function pre_preg_callback($matches) + { + return $this->pre_content; + } + + /** + * Strtoupper function with HTML tags and entities handling. + * + * @param string $str Text to convert + * @return string Converted text + */ + private function _toupper($str) + { + // string can containing HTML tags + $chunks = preg_split('/(<[^>]*>)/', $str, null, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE); + + // convert toupper only the text between HTML tags + foreach ($chunks as $idx => $chunk) { + if ($chunk[0] != '<') { + $chunks[$idx] = $this->_strtoupper($chunk); + } + } + + return implode($chunks); + } + + /** + * Strtoupper multibyte wrapper function with HTML entities handling. + * + * @param string $str Text to convert + * @return string Converted text + */ + private function _strtoupper($str) + { + $str = html_entity_decode($str, ENT_COMPAT, $this->charset); + $str = mb_strtoupper($str); + $str = htmlspecialchars($str, ENT_COMPAT, $this->charset); + + return $str; + } +}