Adjust copyrights years
<?php
/**
* SeekQuarry/Yioop --
* Open Source Pure PHP Search Engine, Crawler, and Indexer
*
* Copyright (C) 2009 - 2023 Chris Pollett chris@pollett.org
*
* LICENSE:
*
* 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 3 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*
* END LICENSE
*
* @author Nakul Natu nakul.natu@gmail.com
* @license https://www.gnu.org/licenses/ GPLv3
* @link https://www.seekquarry.com/
* @copyright 2009 - 2023
* @filesource
*/
namespace seekquarry\yioop\library\processors;
use seekquarry\yioop\configs as C;
use seekquarry\yioop\library as L;
use seekquarry\yioop\library\UrlParser;
use seekquarry\yioop\library\PartialZipArchive;
/**
* Used to create crawl summary information
* for PPTX files
*
* @author Nakul Natu
*/
class PptxProcessor extends TextProcessor
{
/**
* Set-ups the any indexing plugins associated with this page
* processor
*
* @param array $plugins an array of indexing plugins which might
* do further processing on the data handles by this page
* processor
* @param int $max_description_len maximal length of a page summary
* @param int $max_links_to_extract maximum number of links to extract
* from a single document
* @param string $summarizer_option CRAWL_CONSTANT specifying what kind
* of summarizer to use self::BASIC_SUMMARIZER,
* self::GRAPH_BASED_SUMMARIZER and self::CENTROID_SUMMARIZER
* self::CENTROID_SUMMARIZER
*/
public function __construct($plugins = [], $max_description_len = null,
$max_links_to_extract = null,
$summarizer_option = self::BASIC_SUMMARIZER)
{
parent::__construct($plugins, $max_description_len,
$max_links_to_extract, $summarizer_option);
/** Register File Types We Handle*/
self::$indexed_file_types[] = "pptx";
self::$mime_processor["application/vnd.openxmlformats-officedocument.".
"presentationml.presentation"] = "PptxProcessor";
}
/**
* Used to extract the title, description and links from
* a pptx file consisting of xml data.
*
* @param string $page pptx(zip) contents
* @param string $url the url where the page contents came from,
* used to canonicalize relative links
*
* @return array a summary of the contents of the page
*
*/
public function process($page, $url)
{
$summary = null;
// Open zip archive
$zip = new PartialZipArchive($page);
$buf= $zip->getFromName("docProps/core.xml");
if ($buf) {
$dom = self::dom($buf);
if ($dom !== false) {
// Get the title
$summary[self::TITLE] = self::title($dom);
}
}
$buf = $zip->getFromName("docProps/app.xml");
if ($buf) {
// Get number of slides present
$dom = self::dom($buf);
$num_slides = self::numSlides($dom);
} else {
/* go for an upper bound on number of slides (might happen on
partial download of pptx file)
*/
$num_slides = $zip->numFiles();
}
$summary[self::DESCRIPTION] = "";
$summary[self::LINKS] = [];
$lang = null;
for ($i = 1; $i <= $num_slides; $i++) {
$buf = $zip->getFromName("ppt/slides/slide" . $i . ".xml");
if ($buf) {
/* Get description , language and url links associated
with each slide*/
$dom = self::dom($buf);
$description = self::slideText($dom);
if (strlen($summary[self::DESCRIPTION]) + strlen($description)
< self::$max_description_len) {
$summary[self::DESCRIPTION] .= $description;
}
if (!$lang) {
$lang = self::lang($dom);
if ($lang) {
$summary[self::LANG] = $lang;
}
}
$summary[self::LINKS] = array_merge($summary[self::LINKS],
self::links($dom, $url));
}
}
return $summary;
}
/**
* Returns up to MAX_LINK_PER_PAGE many links from the supplied
* dom object where links have been canonicalized according to
* the supplied $site information.
*
* @param object $dom a document object with links on it
* @param string $site a string containing a url
*
* @return array links from the $dom object
*/
public static function links($dom, $site)
{
$sites = [];
$xpath = new \DOMXPath($dom);
$paras = $xpath->evaluate("/p:sld//p:cSld//p:spTree//p:sp//
p:txBody//a:p//a:r//a:rPr//a:hlinkClick");
$i = 0;
foreach ($paras as $para) {
if (self::$max_links_to_extract < 0 ||
$i < self::$max_links_to_extract) {
if (empty($para->parentNode->parentNode->
getElementsByTagName("t")->item(0)->nodeValue)) {
continue;
}
$hlink = $para->parentNode->parentNode->
getElementsByTagName("t")->item(0)->nodeValue;
$url = UrlParser::canonicalLink(
$hlink, $site);
$len = strlen($url);
if (!UrlParser::checkRecursiveUrl($url) &&
strlen($url) < C\MAX_URL_LEN && $len > 0) {
if (isset($sites[$url])) {
$sites[$url] .= " ".$hlink;
} else {
$sites[$url] = $hlink;
}
}
}
$i++;
}
return $sites;
}
/**
* Return a document object based on a string containing the contents of
* a web page
*
* @param string $page xml document
*
* @return object document object
*/
public static function dom($page)
{
$dom = new \DOMDocument();
set_error_handler(null);
@$dom->loadXML($page);
set_error_handler(C\NS_CONFIGS . "yioop_error_handler");
return $dom;
}
/**
* Returns powerpoint head title of a pptx based on its document object
*
* @param object $dom a document object to extract a title from.
* @return string a title of the page
*
*/
public static function title($dom)
{
$core_properties = $dom->getElementsByTagName("coreProperties");
$title = "";
if (!empty($core_properties) && !empty($core_properties->item(0))) {
$property = $core_properties->item(0);
$titles = $property->getElementsByTagName("title");
if (!empty($titles) && !empty($titles->item(0))) {
$title = $titles->item(0)->nodeValue;
}
}
return $title;
}
/**
* Returns number of slides of pptx based on its document object
*
* @param object $dom a document object to extract a title from.
* @return number number of slides
*
*/
public static function numSlides($dom)
{
$properties = $dom->getElementsByTagName("Properties");
$number = 0;
if (!empty($properties) && !empty($properties->item(0))) {
$property = $properties->item(0);
$slides = $property->getElementsByTagName("Slides");
if (!empty($slides->item(0))) {
$number = $slides->item(0)->nodeValue;
}
}
return $number;
}
/**
* Determines the language of the xml document by looking at the
* language attribute of a tag.
*
* @param object $dom a document object to check the language of
*
* @return string language tag for guessed language
*/
public static function lang($dom)
{
$xpath = new \DOMXPath($dom);
$languages = $xpath->evaluate("/p:sld//p:cSld//p:spTree//
p:sp//p:txBody//a:p//a:r//a:rPr");
if (empty($languages) || empty($languages->item(0))) {
return false;
}
return $languages->item(0)->getAttribute("lang");
}
/**
* Returns descriptive text concerning a pptx slide based on its document
* object
*
* @param object $dom a document object to extract a description from.
* @return string a description of the slide
*/
public static function slideText($dom)
{
$xpath = new \DOMXPath($dom);
$paragraphs = $xpath->evaluate("//a:p");
$description = "";
$len = 0;
foreach ($paragraphs as $paragraph) {
if (empty($paragraph)) {
continue;
}
$text = $paragraph->nodeValue."\n\n";
$text_len = strlen($text);
$len += $text_len;
if ($len > self::$max_description_len) {break; }
$description .= $text;
}
return $description;
}
}