<?php
/*
Question2Answer by Gideon Greenspan and contributors
http://www.question2answer.org/
File: qa-include/qa-viewer-basic.php
Description: Basic viewer module for displaying HTML or plain text
This program 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.
This program 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.
More about this license: http://www.question2answer.org/license.php
*/
class qa_viewer_basic
{
private $htmllineseparators;
private $htmlparagraphseparators;
public function load_module($localdir, $htmldir)
{
$this->htmllineseparators='br|option';
$this->htmlparagraphseparators='address|applet|blockquote|center|cite|col|div|dd|dl|dt|embed|form|frame|frameset|h1|h2|h3|h4|h5|h6'.
'|hr|iframe|input|li|marquee|ol|p|pre|samp|select|spacer|table|tbody|td|textarea|tfoot|th|thead|tr|ul';
}
public function calc_quality($content, $format)
{
if ( ($format=='') || ($format=='html') )
return 1.0;
return 0.0001; // if there's nothing better this will give an error message for unknown formats
}
public function get_html($content, $format, $options)
{
if ($format=='html') {
$html=qa_sanitize_html($content, @$options['linksnewwindow'], false); // sanitize again for display, for extra safety, and due to new window setting
if (isset($options['blockwordspreg'])) { // filtering out blocked words inline within HTML is pretty complex, e.g. p<b>oo</b>p must be caught
require_once QA_INCLUDE_DIR.'util/string.php';
$html=preg_replace('/<\s*('.$this->htmllineseparators.')[^A-Za-z0-9]/i', "\n\\0", $html); // tags to single new line
$html=preg_replace('/<\s*('.$this->htmlparagraphseparators.')[^A-Za-z0-9]/i', "\n\n\\0", $html); // tags to double new line
preg_match_all('/<[^>]*>/', $html, $pregmatches, PREG_OFFSET_CAPTURE); // find tag positions and lengths
$tagmatches=$pregmatches[0];
$text=preg_replace('/<[^>]*>/', '', $html); // effectively strip_tags() but use same regexp as above to ensure consistency
$blockmatches=qa_block_words_match_all($text, $options['blockwordspreg']); // search for blocked words within text
$nexttagmatch=array_shift($tagmatches);
$texttohtml=0;
$htmlshift=0;
foreach ($blockmatches as $textoffset => $textlength) {
while ( isset($nexttagmatch) && ($nexttagmatch[1]<=($textoffset+$texttohtml)) ) { // keep text and html in sync
$texttohtml+=strlen($nexttagmatch[0]);
$nexttagmatch=array_shift($tagmatches);
}
while (1) {
$replacepart=$textlength;
if (isset($nexttagmatch))
$replacepart=min($replacepart, $nexttagmatch[1]-($textoffset+$texttohtml)); // stop replacing early if we hit an HTML tag
$replacelength=qa_strlen(substr($text, $textoffset, $replacepart)); // to work with multi-byte characters
$html=substr_replace($html, str_repeat('*', $replacelength), $textoffset+$texttohtml+$htmlshift, $replacepart);
$htmlshift+=$replacelength-$replacepart; // HTML might have moved around if we replaced multi-byte characters
if ($replacepart>=$textlength)
break; // we have replaced everything expected, otherwise more left (due to hitting an HTML tag)
$textlength-=$replacepart;
$textoffset+=$replacepart;
$texttohtml+=strlen($nexttagmatch[0]);
$nexttagmatch=array_shift($tagmatches);
}
}
}
if (@$options['showurllinks']) { // we need to ensure here that we don't put new links inside existing ones
require_once QA_INCLUDE_DIR.'util/string.php';
$htmlunlinkeds=array_reverse(preg_split('|<[Aa]\s+[^>]+>.*</[Aa]\s*>|', $html, -1, PREG_SPLIT_OFFSET_CAPTURE)); // start from end so we substitute correctly
foreach ($htmlunlinkeds as $htmlunlinked) { // and that we don't detect links inside HTML, e.g. <img src="http://...">
$thishtmluntaggeds=array_reverse(preg_split('/<[^>]*>/', $htmlunlinked[0], -1, PREG_SPLIT_OFFSET_CAPTURE)); // again, start from end
foreach ($thishtmluntaggeds as $thishtmluntagged) {
$innerhtml=$thishtmluntagged[0];
if (is_numeric(strpos($innerhtml, '://'))) { // quick test first
$newhtml=qa_html_convert_urls($innerhtml, qa_opt('links_in_new_window'));
$html=substr_replace($html, $newhtml, $htmlunlinked[1]+$thishtmluntagged[1], strlen($innerhtml));
}
}
}
}
}
elseif ($format=='') {
if (isset($options['blockwordspreg'])) {
require_once QA_INCLUDE_DIR.'util/string.php';
$content=qa_block_words_replace($content, $options['blockwordspreg']);
}
$html=qa_html($content, true);
if (@$options['showurllinks']) {
require_once QA_INCLUDE_DIR.'app/format.php';
$html=qa_html_convert_urls($html, qa_opt('links_in_new_window'));
}
}
else
$html='[no viewer found for format: '.qa_html($format).']'; // for unknown formats
return $html;
}
public function get_text($content, $format, $options)
{
if ($format=='html') {
$text=strtr($content, "\n\r\t", ' '); // convert all white space in HTML to spaces
$text=preg_replace('/<\s*('.$this->htmllineseparators.')[^A-Za-z0-9]/i', "\n\\0", $text); // tags to single new line
$text=preg_replace('/<\s*('.$this->htmlparagraphseparators.')[^A-Za-z0-9]/i', "\n\n\\0", $text); // tags to double new line
$text=strip_tags($text); // all tags removed
$text=preg_replace('/ +/', ' ', $text); // combine multiple spaces into one
$text=preg_replace('/ *\n */', "\n", $text); // remove spaces either side new lines
$text=preg_replace('/\n\n\n+/', "\n\n", $text); // more than two new lines combine into two
$text=strtr($text, array(
'"' => "\x22",
'&' => "\x26",
''' => "\x27",
'<' => "\x3C",
'>' => "\x3E",
' ' => " ",
'"' => "\x22",
'&' => "\x26",
'<' => "\x3C",
'>' => "\x3E",
)); // base HTML entities (others should not be stored in database)
$text=trim($text);
}
elseif ($format=='')
$text=$content;
else
$text='[no viewer found for format: '.$format.']'; // for unknown formats
if (isset($options['blockwordspreg'])) {
require_once QA_INCLUDE_DIR.'util/string.php';
$text=qa_block_words_replace($text, $options['blockwordspreg']);
}
return $text;
}
}