mirror of
https://github.com/renbaoshuo/S2OJ.git
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678 lines
23 KiB
PHP
678 lines
23 KiB
PHP
<?php
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/*************************************************************************
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* *
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* Converts HTML to formatted plain text *
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* *
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* Portions Copyright (c) 2005-2007 Jon Abernathy <jon@chuggnutt.com> *
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* *
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* This script is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 2 of the License, or *
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* (at your option) any later version. *
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* *
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* The GNU General Public License can be found at *
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* http://www.gnu.org/copyleft/gpl.html. *
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* *
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* This script is distributed in the hope that it will be useful, *
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* but WITHOUT ANY WARRANTY; without even the implied warranty of *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
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* GNU General Public License for more details. *
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* *
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*************************************************************************/
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/**
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* Converts HTML to formatted plain text
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*/
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class Html2Text
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{
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/**
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* Contains the HTML content to convert.
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*
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* @type string
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*/
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protected $html;
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/**
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* Contains the converted, formatted text.
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*
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* @type string
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*/
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protected $text;
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/**
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* Maximum width of the formatted text, in columns.
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*
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* Set this value to 0 (or less) to ignore word wrapping
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* and not constrain text to a fixed-width column.
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*
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* @type integer
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*/
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protected $width = 70;
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/**
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* List of preg* regular expression patterns to search for,
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* used in conjunction with $replace.
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*
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* @type array
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* @see $replace
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*/
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protected $search = array(
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"/\r/", // Non-legal carriage return
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"/[\n\t]+/", // Newlines and tabs
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'/<head[^>]*>.*?<\/head>/i', // <head>
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'/<script[^>]*>.*?<\/script>/i', // <script>s -- which strip_tags supposedly has problems with
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'/<style[^>]*>.*?<\/style>/i', // <style>s -- which strip_tags supposedly has problems with
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'/<p[^>]*>/i', // <P>
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'/<br[^>]*>/i', // <br>
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'/<i[^>]*>(.*?)<\/i>/i', // <i>
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'/<em[^>]*>(.*?)<\/em>/i', // <em>
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'/(<ul[^>]*>|<\/ul>)/i', // <ul> and </ul>
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'/(<ol[^>]*>|<\/ol>)/i', // <ol> and </ol>
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'/(<dl[^>]*>|<\/dl>)/i', // <dl> and </dl>
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'/<li[^>]*>(.*?)<\/li>/i', // <li> and </li>
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'/<dd[^>]*>(.*?)<\/dd>/i', // <dd> and </dd>
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'/<dt[^>]*>(.*?)<\/dt>/i', // <dt> and </dt>
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'/<li[^>]*>/i', // <li>
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'/<hr[^>]*>/i', // <hr>
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'/<div[^>]*>/i', // <div>
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'/(<table[^>]*>|<\/table>)/i', // <table> and </table>
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'/(<tr[^>]*>|<\/tr>)/i', // <tr> and </tr>
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'/<td[^>]*>(.*?)<\/td>/i', // <td> and </td>
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'/<span class="_html2text_ignore">.+?<\/span>/i' // <span class="_html2text_ignore">...</span>
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);
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/**
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* List of pattern replacements corresponding to patterns searched.
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*
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* @type array
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* @see $search
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*/
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protected $replace = array(
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'', // Non-legal carriage return
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' ', // Newlines and tabs
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'', // <head>
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'', // <script>s -- which strip_tags supposedly has problems with
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'', // <style>s -- which strip_tags supposedly has problems with
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"\n\n", // <P>
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"\n", // <br>
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'_\\1_', // <i>
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'_\\1_', // <em>
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"\n\n", // <ul> and </ul>
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"\n\n", // <ol> and </ol>
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"\n\n", // <dl> and </dl>
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"\t* \\1\n", // <li> and </li>
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" \\1\n", // <dd> and </dd>
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"\t* \\1", // <dt> and </dt>
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"\n\t* ", // <li>
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"\n-------------------------\n", // <hr>
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"<div>\n", // <div>
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"\n\n", // <table> and </table>
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"\n", // <tr> and </tr>
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"\t\t\\1\n", // <td> and </td>
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"" // <span class="_html2text_ignore">...</span>
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);
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/**
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* List of preg* regular expression patterns to search for,
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* used in conjunction with $ent_replace.
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*
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* @type array
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* @see $ent_replace
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*/
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protected $ent_search = array(
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'/&(nbsp|#160);/i', // Non-breaking space
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'/&(quot|rdquo|ldquo|#8220|#8221|#147|#148);/i',
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// Double quotes
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'/&(apos|rsquo|lsquo|#8216|#8217);/i', // Single quotes
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'/>/i', // Greater-than
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'/</i', // Less-than
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'/&(copy|#169);/i', // Copyright
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'/&(trade|#8482|#153);/i', // Trademark
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'/&(reg|#174);/i', // Registered
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'/&(mdash|#151|#8212);/i', // mdash
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'/&(ndash|minus|#8211|#8722);/i', // ndash
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'/&(bull|#149|#8226);/i', // Bullet
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'/&(pound|#163);/i', // Pound sign
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'/&(euro|#8364);/i', // Euro sign
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'/&(amp|#38);/i', // Ampersand: see _converter()
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'/[ ]{2,}/', // Runs of spaces, post-handling
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);
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/**
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* List of pattern replacements corresponding to patterns searched.
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*
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* @type array
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* @see $ent_search
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*/
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protected $ent_replace = array(
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' ', // Non-breaking space
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'"', // Double quotes
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"'", // Single quotes
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'>',
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'<',
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'(c)',
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'(tm)',
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'(R)',
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'--',
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'-',
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'*',
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'£',
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'EUR', // Euro sign. € ?
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'|+|amp|+|', // Ampersand: see _converter()
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' ', // Runs of spaces, post-handling
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);
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/**
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* List of preg* regular expression patterns to search for
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* and replace using callback function.
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*
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* @type array
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*/
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protected $callback_search = array(
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'/<(a) [^>]*href=("|\')([^"\']+)\2([^>]*)>(.*?)<\/a>/i', // <a href="">
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'/<(h)[123456]( [^>]*)?>(.*?)<\/h[123456]>/i', // h1 - h6
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'/<(b)( [^>]*)?>(.*?)<\/b>/i', // <b>
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'/<(strong)( [^>]*)?>(.*?)<\/strong>/i', // <strong>
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'/<(th)( [^>]*)?>(.*?)<\/th>/i', // <th> and </th>
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);
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/**
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* List of preg* regular expression patterns to search for in PRE body,
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* used in conjunction with $pre_replace.
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*
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* @type array
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* @see $pre_replace
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*/
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protected $pre_search = array(
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"/\n/",
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"/\t/",
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'/ /',
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'/<pre[^>]*>/',
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'/<\/pre>/'
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);
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/**
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* List of pattern replacements corresponding to patterns searched for PRE body.
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*
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* @type array
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* @see $pre_search
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*/
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protected $pre_replace = array(
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'<br>',
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' ',
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' ',
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'',
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''
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);
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/**
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* Temporary workspace used during PRE processing.
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*
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* @type string
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*/
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protected $pre_content = '';
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/**
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* Contains a list of HTML tags to allow in the resulting text.
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*
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* @type string
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* @see set_allowed_tags()
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*/
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protected $allowed_tags = '';
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/**
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* Contains the base URL that relative links should resolve to.
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*
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* @type string
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*/
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protected $url;
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/**
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* Indicates whether content in the $html variable has been converted yet.
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*
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* @type boolean
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* @see $html, $text
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*/
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protected $_converted = false;
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/**
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* Contains URL addresses from links to be rendered in plain text.
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*
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* @type array
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* @see _build_link_list()
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*/
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protected $_link_list = array();
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/**
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* Various configuration options (able to be set in the constructor)
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*
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* @type array
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*/
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protected $_options = array(
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// 'none'
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// 'inline' (show links inline)
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// 'nextline' (show links on the next line)
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// 'table' (if a table of link URLs should be listed after the text.
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'do_links' => 'inline',
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// Maximum width of the formatted text, in columns.
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// Set this value to 0 (or less) to ignore word wrapping
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// and not constrain text to a fixed-width column.
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'width' => 70,
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);
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/**
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* Constructor.
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*
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* If the HTML source string (or file) is supplied, the class
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* will instantiate with that source propagated, all that has
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* to be done it to call get_text().
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*
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* @param string $source HTML content
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* @param boolean $from_file Indicates $source is a file to pull content from
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* @param array $options Set configuration options
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*/
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public function __construct($source = '', $from_file = false, $options = array())
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{
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$this->_options = array_merge($this->_options, $options);
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if (!empty($source)) {
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$this->set_html($source, $from_file);
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}
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$this->set_base_url();
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}
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/**
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* Loads source HTML into memory, either from $source string or a file.
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*
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* @param string $source HTML content
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* @param boolean $from_file Indicates $source is a file to pull content from
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*/
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public function set_html($source, $from_file = false)
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{
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if ($from_file && file_exists($source)) {
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$this->html = file_get_contents($source);
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} else {
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$this->html = $source;
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}
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$this->_converted = false;
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}
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/**
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* Returns the text, converted from HTML.
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*
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* @return string
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*/
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public function get_text()
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{
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if (!$this->_converted) {
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$this->_convert();
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}
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return $this->text;
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}
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/**
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* Prints the text, converted from HTML.
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*/
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public function print_text()
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{
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print $this->get_text();
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}
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/**
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* Alias to print_text(), operates identically.
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*
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* @see print_text()
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*/
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public function p()
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{
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print $this->get_text();
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}
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/**
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* Sets the allowed HTML tags to pass through to the resulting text.
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*
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* Tags should be in the form "<p>", with no corresponding closing tag.
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* @param string $allowed_tags
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*/
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public function set_allowed_tags($allowed_tags = '')
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{
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if (!empty($allowed_tags)) {
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$this->allowed_tags = $allowed_tags;
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}
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}
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/**
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* Sets a base URL to handle relative links.
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*
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* @param string $url
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*/
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public function set_base_url($url = '')
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{
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if (empty($url)) {
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if (!empty($_SERVER['HTTP_HOST'])) {
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$this->url = 'http://' . $_SERVER['HTTP_HOST'];
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} else {
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$this->url = '';
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}
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} else {
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// Strip any trailing slashes for consistency (relative
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// URLs may already start with a slash like "/file.html")
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if (substr($url, -1) == '/') {
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$url = substr($url, 0, -1);
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}
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$this->url = $url;
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}
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}
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/**
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* Workhorse function that does actual conversion (calls _converter() method).
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*/
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protected function _convert()
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{
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// Variables used for building the link list
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$this->_link_list = array();
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$text = trim(stripslashes($this->html));
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// Convert HTML to TXT
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$this->_converter($text);
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// Add link list
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if (!empty($this->_link_list)) {
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$text .= "\n\nLinks:\n------\n";
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foreach ($this->_link_list as $idx => $url) {
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$text .= '[' . ($idx + 1) . '] ' . $url . "\n";
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}
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}
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$this->text = $text;
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$this->_converted = true;
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}
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/**
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* Workhorse function that does actual conversion.
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*
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* First performs custom tag replacement specified by $search and
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* $replace arrays. Then strips any remaining HTML tags, reduces whitespace
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* and newlines to a readable format, and word wraps the text to
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* $this->_options['width'] characters.
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*
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* @param string $text Reference to HTML content string
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*/
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protected function _converter(&$text)
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{
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// Convert <BLOCKQUOTE> (before PRE!)
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$this->_convert_blockquotes($text);
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// Convert <PRE>
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$this->_convert_pre($text);
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// Run our defined tags search-and-replace
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$text = preg_replace($this->search, $this->replace, $text);
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// Run our defined tags search-and-replace with callback
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$text = preg_replace_callback($this->callback_search, array($this, '_preg_callback'), $text);
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// Strip any other HTML tags
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$text = strip_tags($text, $this->allowed_tags);
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// Run our defined entities/characters search-and-replace
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$text = preg_replace($this->ent_search, $this->ent_replace, $text);
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// Replace known html entities
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$text = html_entity_decode($text, ENT_QUOTES);
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// Remove unknown/unhandled entities (this cannot be done in search-and-replace block)
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$text = preg_replace('/&([a-zA-Z0-9]{2,6}|#[0-9]{2,4});/', '', $text);
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// Convert "|+|amp|+|" into "&", need to be done after handling of unknown entities
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// This properly handles situation of "&quot;" in input string
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$text = str_replace('|+|amp|+|', '&', $text);
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// Bring down number of empty lines to 2 max
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$text = preg_replace("/\n\s+\n/", "\n\n", $text);
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$text = preg_replace("/[\n]{3,}/", "\n\n", $text);
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// remove leading empty lines (can be produced by eg. P tag on the beginning)
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$text = ltrim($text, "\n");
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// Wrap the text to a readable format
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// for PHP versions >= 4.0.2. Default width is 75
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// If width is 0 or less, don't wrap the text.
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if ($this->_options['width'] > 0) {
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$text = wordwrap($text, $this->_options['width']);
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}
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}
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/**
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* Helper function called by preg_replace() on link replacement.
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*
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* Maintains an internal list of links to be displayed at the end of the
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* text, with numeric indices to the original point in the text they
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* appeared. Also makes an effort at identifying and handling absolute
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* and relative links.
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*
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* @param string $link URL of the link
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* @param string $display Part of the text to associate number with
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* @param null $link_override
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* @return string
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*/
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protected function _build_link_list($link, $display, $link_override = null)
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{
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$link_method = ($link_override) ? $link_override : $this->_options['do_links'];
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if ($link_method == 'none') {
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return $display;
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}
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// Ignored link types
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if (preg_match('!^(javascript:|mailto:|#)!i', $link)) {
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return $display;
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}
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if (preg_match('!^([a-z][a-z0-9.+-]+:)!i', $link)) {
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$url = $link;
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} else {
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$url = $this->url;
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if (substr($link, 0, 1) != '/') {
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$url .= '/';
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}
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$url .= "$link";
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}
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if ($link_method == 'table') {
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if (($index = array_search($url, $this->_link_list)) === false) {
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$index = count($this->_link_list);
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$this->_link_list[] = $url;
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}
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return $display . ' [' . ($index + 1) . ']';
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} elseif ($link_method == 'nextline') {
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return $display . "\n[" . $url . ']';
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} else { // link_method defaults to inline
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return $display . ' [' . $url . ']';
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}
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}
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/**
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* Helper function for PRE body conversion.
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*
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* @param string $text HTML content
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*/
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protected function _convert_pre(&$text)
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{
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// get the content of PRE element
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while (preg_match('/<pre[^>]*>(.*)<\/pre>/ismU', $text, $matches)) {
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$this->pre_content = $matches[1];
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// Run our defined tags search-and-replace with callback
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$this->pre_content = preg_replace_callback(
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$this->callback_search,
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array($this, '_preg_callback'),
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$this->pre_content
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);
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// convert the content
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$this->pre_content = sprintf(
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'<div><br>%s<br></div>',
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preg_replace($this->pre_search, $this->pre_replace, $this->pre_content)
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);
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// replace the content (use callback because content can contain $0 variable)
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$text = preg_replace_callback(
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'/<pre[^>]*>.*<\/pre>/ismU',
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array($this, '_preg_pre_callback'),
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$text,
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1
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|
);
|
|
|
|
// free memory
|
|
$this->pre_content = '';
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Helper function for BLOCKQUOTE body conversion.
|
|
*
|
|
* @param string $text HTML content
|
|
*/
|
|
protected function _convert_blockquotes(&$text)
|
|
{
|
|
if (preg_match_all('/<\/*blockquote[^>]*>/i', $text, $matches, PREG_OFFSET_CAPTURE)) {
|
|
$start = 0;
|
|
$taglen = 0;
|
|
$level = 0;
|
|
$diff = 0;
|
|
foreach ($matches[0] as $m) {
|
|
if ($m[0][0] == '<' && $m[0][1] == '/') {
|
|
$level--;
|
|
if ($level < 0) {
|
|
$level = 0; // malformed HTML: go to next blockquote
|
|
} elseif ($level > 0) {
|
|
// skip inner blockquote
|
|
} else {
|
|
$end = $m[1];
|
|
$len = $end - $taglen - $start;
|
|
// Get blockquote content
|
|
$body = substr($text, $start + $taglen - $diff, $len);
|
|
|
|
// Set text width
|
|
$p_width = $this->_options['width'];
|
|
if ($this->_options['width'] > 0) $this->_options['width'] -= 2;
|
|
// Convert blockquote content
|
|
$body = trim($body);
|
|
$this->_converter($body);
|
|
// Add citation markers and create PRE block
|
|
$body = preg_replace('/((^|\n)>*)/', '\\1> ', trim($body));
|
|
$body = '<pre>' . htmlspecialchars($body) . '</pre>';
|
|
// Re-set text width
|
|
$this->_options['width'] = $p_width;
|
|
// Replace content
|
|
$text = substr($text, 0, $start - $diff)
|
|
. $body . substr($text, $end + strlen($m[0]) - $diff);
|
|
|
|
$diff = $len + $taglen + strlen($m[0]) - strlen($body);
|
|
unset($body);
|
|
}
|
|
} else {
|
|
if ($level == 0) {
|
|
$start = $m[1];
|
|
$taglen = strlen($m[0]);
|
|
}
|
|
$level++;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Callback function for preg_replace_callback use.
|
|
*
|
|
* @param array $matches PREG matches
|
|
* @return string
|
|
*/
|
|
protected function _preg_callback($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':
|
|
// override the link method
|
|
$link_override = null;
|
|
if (preg_match('/_html2text_link_(\w+)/', $matches[4], $link_override_match)) {
|
|
$link_override = $link_override_match[1];
|
|
}
|
|
// Remove spaces in URL (#1487805)
|
|
$url = str_replace(' ', '', $matches[3]);
|
|
|
|
return $this->_build_link_list($url, $matches[5], $link_override);
|
|
}
|
|
return '';
|
|
}
|
|
|
|
/**
|
|
* Callback function for preg_replace_callback use in PRE content handler.
|
|
*
|
|
* @param array $matches PREG matches
|
|
* @return string
|
|
*/
|
|
protected function _preg_pre_callback(
|
|
/** @noinspection PhpUnusedParameterInspection */
|
|
$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 contain 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.
|
|
* Forces mb_strtoupper-call to UTF-8.
|
|
*
|
|
* @param string $str Text to convert
|
|
* @return string Converted text
|
|
*/
|
|
private function _strtoupper($str)
|
|
{
|
|
$str = html_entity_decode($str, ENT_COMPAT);
|
|
|
|
if (function_exists('mb_strtoupper'))
|
|
$str = mb_strtoupper($str, 'UTF-8');
|
|
else
|
|
$str = strtoupper($str);
|
|
|
|
$str = htmlspecialchars($str, ENT_COMPAT);
|
|
|
|
return $str;
|
|
}
|
|
}
|