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Diffstat (limited to 'program/lib/html2text.php')
| -rw-r--r-- | program/lib/html2text.php | 451 |
1 files changed, 451 insertions, 0 deletions
diff --git a/program/lib/html2text.php b/program/lib/html2text.php new file mode 100644 index 000000000..7d7d9d1f4 --- /dev/null +++ b/program/lib/html2text.php @@ -0,0 +1,451 @@ +<?php + +/************************************************************************* +* * +* class.html2text.inc * +* * +************************************************************************* +* * +* Converts HTML to formatted plain text * +* * +* Copyright (c) 2005 Jon Abernathy <jon@chuggnutt.com> * +* All rights reserved. * +* * +* This script is free software; you can redistribute it and/or modify * +* it under the terms of the GNU General Public License as published by * +* the Free Software Foundation; either version 2 of the License, or * +* (at your option) any later version. * +* * +* The GNU General Public License can be found at * +* http://www.gnu.org/copyleft/gpl.html. * +* * +* This script is distributed in the hope that it will be useful, * +* but WITHOUT ANY WARRANTY; without even the implied warranty of * +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * +* GNU General Public License for more details. * +* * +* Author(s): Jon Abernathy <jon@chuggnutt.com> * +* * +* Last modified: 04/06/05 * +* Modified: 2004/05/19 (tbr) * +* * +*************************************************************************/ + + +/** +* 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. +* +* @author Jon Abernathy <jon@chuggnutt.com> +* @version 0.6.1 +* @since PHP 4.0.2 +*/ +class html2text +{ + + /** + * Contains the HTML content to convert. + * + * @var string $html + * @access public + */ + var $html; + + /** + * Contains the converted, formatted text. + * + * @var string $text + * @access public + */ + var $text; + + /** + * Maximum width of the formatted text, in columns. + * + * @var integer $width + * @access public + */ + var $width = 70; + + /** + * List of preg* regular expression patterns to search for, + * used in conjunction with $replace. + * + * @var array $search + * @access public + * @see $replace + */ + var $search = array( + "/\r/", // Non-legal carriage return + "/[\n\t]+/", // Newlines and tabs + '/<script[^>]*>.*?<\/script>/i', // <script>s -- which strip_tags supposedly has problems with + //'/<!-- .* -->/', // Comments -- which strip_tags might have problem a with + '/<a [^>]*href=("|\')([^"\']+)\1[^>]*>(.+?)<\/a>/ie', // <a href=""> + '/<h[123][^>]*>(.+?)<\/h[123]>/ie', // H1 - H3 + '/<h[456][^>]*>(.+?)<\/h[456]>/ie', // H4 - H6 + '/<p[^>]*>/i', // <P> + '/<br[^>]*>/i', // <br> + '/<b[^>]*>(.+?)<\/b>/ie', // <b> + '/<i[^>]*>(.+?)<\/i>/i', // <i> + '/(<ul[^>]*>|<\/ul>)/i', // <ul> and </ul> + '/(<ol[^>]*>|<\/ol>)/i', // <ol> and </ol> + '/<li[^>]*>/i', // <li> + '/<hr[^>]*>/i', // <hr> + '/(<table[^>]*>|<\/table>)/i', // <table> and </table> + '/(<tr[^>]*>|<\/tr>)/i', // <tr> and </tr> + '/<td[^>]*>(.+?)<\/td>/i', // <td> and </td> + '/<th[^>]*>(.+?)<\/th>/ie', // <th> and </th> + '/ /i', + '/"/i', + '/>/i', + '/</i', + '/&(amp|#38);/i', + '/©/i', + '/™/i', + '/“/', + '/”/', + '/–/', + '/&#(8217|39);/', + '/©/', + '/™/', + '/—/', + '/“/', + '/”/', + '/•/', + '/®/i', + '/•/i', + '/&[&;]+;/i' + ); + + /** + * List of pattern replacements corresponding to patterns searched. + * + * @var array $replace + * @access public + * @see $search + */ + var $replace = array( + '', // Non-legal carriage return + ' ', // Newlines and tabs + '', // <script>s -- which strip_tags supposedly has problems with + //'', // Comments -- which strip_tags might have problem a with + '$this->_build_link_list("\\2", "\\3")', // <a href=""> + "strtoupper(\"\n\n\\1\n\n\")", // H1 - H3 + "ucwords(\"\n\n\\1\n\")", // H4 - H6 + "\n\n", // <P> + "\n", // <br> + 'strtoupper("\\1")', // <b> + '_\\1_', // <i> + "\n\n", // <ul> and </ul> + "\n\n", // <ol> and </ol> + "\t*", // <li> + "\n-------------------------\n", // <hr> + "\n\n", // <table> and </table> + "\n", // <tr> and </tr> + "\t\t\\1\n", // <td> and </td> + "strtoupper(\"\t\t\\1\n\")", // <th> and </th> + ' ', + '"', + '>', + '<', + '&', + '(c)', + '(tm)', + '"', + '"', + '-', + "'", + '(c)', + '(tm)', + '--', + '"', + '"', + '*', + '(R)', + '*', + '' + ); + + /** + * Contains a list of HTML tags to allow in the resulting text. + * + * @var string $allowed_tags + * @access public + * @see set_allowed_tags() + */ + var $allowed_tags = ''; + + /** + * Contains the base URL that relative links should resolve to. + * + * @var string $url + * @access public + */ + var $url; + + /** + * Indicates whether content in the $html variable has been converted yet. + * + * @var boolean $converted + * @access private + * @see $html, $text + */ + var $_converted = false; + + /** + * Contains URL addresses from links to be rendered in plain text. + * + * @var string $link_list + * @access private + * @see _build_link_list() + */ + var $_link_list = array(); + + /** + * Boolean flag, true if a table of link URLs should be listed after the text. + * + * @var boolean $_do_links + * @access private + * @see html2text() + */ + var $_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_link_table indicate whether a table of link URLs is desired + * @access public + * @return void + */ + function html2text( $source = '', $from_file = false, $produce_link_table = true ) + { + if ( !empty($source) ) { + $this->set_html($source, $from_file); + } + $this->set_base_url(); + $this->_do_links = $produce_link_table; + } + + /** + * 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 + * @access public + * @return void + */ + function set_html( $source, $from_file = false ) + { + $this->html = $source; + + if ( $from_file && file_exists($source) ) { + $fp = fopen($source, 'r'); + $this->html = fread($fp, filesize($source)); + fclose($fp); + } + + $this->_converted = false; + } + + /** + * Returns the text, converted from HTML. + * + * @access public + * @return string + */ + function get_text() + { + if ( !$this->_converted ) { + $this->_convert(); + } + + return $this->text; + } + + /** + * Prints the text, converted from HTML. + * + * @access public + * @return void + */ + function print_text() + { + print $this->get_text(); + } + + /** + * Alias to print_text(), operates identically. + * + * @access public + * @return void + * @see print_text() + */ + function p() + { + 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. + * + * @access public + * @return void + */ + function set_allowed_tags( $allowed_tags = '' ) + { + if ( !empty($allowed_tags) ) { + $this->allowed_tags = $allowed_tags; + } + } + + /** + * Sets a base URL to handle relative links. + * + * @access public + * @return void + */ + function set_base_url( $url = '' ) + { + if ( empty($url) ) { + $this->url = 'http://' . $_SERVER['HTTP_HOST']; + } else { + // Strip any trailing slashes for consistency (relative + // URLs may already start with a slash like "/file.html") + if ( substr($url, -1) == '/' ) { + $url = substr($url, 0, -1); + } + $this->url = $url; + } + } + + /** + * Workhorse function that does actual conversion. + * + * 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 + * $width characters. + * + * @access private + * @return void + */ + function _convert() + { + // Variables used for building the link list + //$link_count = 1; + //$this->_link_list = ''; + + $text = trim(stripslashes($this->html)); + + // Run our defined search-and-replace + $text = preg_replace($this->search, $this->replace, $text); + + // Strip any other HTML tags + $text = strip_tags($text, $this->allowed_tags); + + // Bring down number of empty lines to 2 max + $text = preg_replace("/\n\s+\n/", "\n", $text); + $text = preg_replace("/[\n]{3,}/", "\n\n", $text); + + // Add link list + if ( sizeof($this->_link_list) ) { + $text .= "\n\nLinks:\n------\n"; + foreach ($this->_link_list as $id => $link) { + $text .= '[' . ($id+1) . '] ' . $link . "\n"; + } + } + + // Wrap the text to a readable format + // for PHP versions >= 4.0.2. Default width is 75 + $text = wordwrap($text, $this->width); + + $this->text = $text; + + $this->_converted = true; + } + + /** + * 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 integer $link_count Counter tracking current link number + * @param string $link URL of the link + * @param string $display Part of the text to associate number with + * @access private + * @return string + */ + function _build_link_list($link, $display) + { + if (! $this->_do_links) return $display; + + $link_lc = strtolower($link); + + if (substr($link_lc, 0, 7) == 'http://' || substr($link_lc, 0, 8) == 'https://' || substr($link_lc, 0, 7) == 'mailto:') + { + $url = $link; + } + else + { + $url = $this->url; + if ($link{0} != '/') { + $url .= '/'; + } + $url .= $link; + } + + $index = array_search($url, $this->_link_list); + if ($index===FALSE) + { + $index = sizeof($this->_link_list); + $this->_link_list[$index] = $url; + } + + return $display . ' [' . ($index+1) . ']'; + } +} + +?>
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