<?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
|
* $width characters.
|
*
|
* @param string Reference to HTML content string
|
*/
|
protected function _converter(&$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 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
|
$this->pre_content = '';
|
}
|
}
|
|
/**
|
* Helper function for BLOCKQUOTE body conversion.
|
*
|
* @param string HTML content
|
*/
|
protected function _convert_blockquotes(&$text)
|
{
|
$level = 0;
|
$offset = 0;
|
while (($start = strpos($text, '<blockquote', $offset)) !== false) {
|
$offset = $start + 12;
|
do {
|
$end = strpos($text, '</blockquote>', $offset);
|
$next = strpos($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 . $line;
|
}
|
|
/**
|
* Callback function for preg_replace_callback use.
|
*
|
* @param array PREG matches
|
* @return string
|
*/
|
public function tags_preg_callback($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, $matches[4]);
|
}
|
}
|
|
/**
|
* Callback function for preg_replace_callback use in PRE content handler.
|
*
|
* @param array PREG matches
|
* @return string
|
*/
|
public function pre_preg_callback($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 containg 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;
|
}
|
}
|
