<?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 Chris Pollett chris@pollett.org
* @license https://www.gnu.org/licenses/ GPL3
* @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;
/**
* Used to create crawl summary information
* for SVG files. This class is a little bit
* weird in that it generates thumbs like the
* image processor classes, but when it gives
* up on the data it falls back to text
* processor handling.
*
* @author Chris Pollett
*/
class SvgProcessor 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[] = "svg";
self::$image_types[] = "svg";
self::$mime_processor["image/svg+xml"] = "SvgProcessor";
}
/**
* Used to extract the title, description and links from
* a string consisting of svg image. If the image is small
* enough, an attempt is made to generate a thumbnail
*
* @param string $page web-page 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)
{
$summary = [];
if (is_string($page)) {
$dom = self::dom($page);
if (!$dom) {
self::closeDanglingTags($page);
$dom = self::dom($page);
}
if ($dom !== false && isset($dom->documentElement)) {
$summary[self::LANG] = "mul";
$summary[self::TITLE] = self::title($dom, $page);
$svg = $dom->documentElement;
if ($svg->hasAttribute("width")) {
$width = $svg->getAttribute("width");
$summary[self::WIDTH] = L\convertPixels($width);
}
if ($svg->hasAttribute("height")) {
$height = $svg->getAttribute("height");
$summary[self::HEIGHT] = L\convertPixels($height);
}
$summary[self::DESCRIPTION] = self::description($dom, $page);
$summary[self::LINKS] = [];
$summary[self::PAGE] = "<!DOCTYPE html>" .
"<html><body><div><img src='data:image/svg+xml;base64," .
base64_encode($page)."' alt='".$summary[self::DESCRIPTION].
"' ></div></body></html>";
if (strlen($page) < C\PAGE_RANGE_REQUEST) {
$thumb_string = self::createSvgThumb($dom, $page);
$summary[self::THUMB] = 'data:image/svg+xml;base64,'.
base64_encode($thumb_string);
}
} else {
$summary = parent::process($page, $url);
}
}
return $summary;
}
/**
* Used to create an svg thumbnail from a dom object
*
* @param object $dom a dom svg image object
* @param string $page content of file to fall back on in case dom
* manipulation fails
* @return string containing svg image of thumb
*/
public static function createSvgThumb($dom, $page)
{
$svg = $dom->documentElement;
if ($svg->hasAttribute("width")) {
$width = $svg->getAttribute("width");
} else {
$width = 600;
}
$width = L\convertPixels($width);
if ($svg->hasAttribute("height")) {
$height = $svg->getAttribute("height");
} else {
$height = 600;
}
$height = L\convertPixels($height);
$svg->setAttributeNS("", "width", "150px");
$svg->setAttributeNS("", "height", "150px");
if (!$svg->hasAttribute("viewBox")) {
$svg->setAttributeNS("", "viewBox", "0 0 $width $height");
}
$thumb_string = $dom->saveXML();
if (!empty($thumb_string)) {
return $thumb_string;
}
$thumb_string = preg_replace('/\<svg\s(^\>+)\>/',
"<svg width='150px' height='150px' >", $page);
return $thumb_string;
}
/**
* Return a document object based on a string containing the contents of
* an SVG page
*
* @param string $page a web page
*
* @return object document object
*/
public static function dom($page)
{
return L\getDomFromString($page);
}
/**
* Returns title of a svg page based on its document object
*
* @param object $dom a document object to extract a title from.
* @param string $page content of file to fall back on in case xpath
* doesn't work
* @return string a title of the page
*
*/
public static function title($dom, $page)
{
$xpath = new \DOMXPath($dom);
$title_parts = ["/svg//title", "/svg//desc"];
$title = "";
foreach ($title_parts as $part) {
$doc_nodes = $xpath->evaluate($part);
foreach ($doc_nodes as $node) {
$title = trim($node->nodeValue);
if (!empty($title)) {
break 2;
}
}
}
if (empty($title)) {
list(, $title) = parent::getBetweenTags($page, 0, "<title",
"</title");
return strip_tags("<title" . $title . "</title>");
}
if (empty($title)) {
list(, $title) = parent::getBetweenTags($page, 0, "<desc",
"</desc");
return strip_tags("<desc" . $title . "</desc>");
}
return $title;
}
/**
* Returns descriptive text concerning a svg page based on its document
* object
*
* @param object $dom a document object to extract a description from.
* @param string $page content of file to fall back on in case xpath
* doesn't work
* @return string a description of the page
*/
public static function description($dom, $page)
{
$sites = [];
$xpath = new \DOMXPath($dom);
$description = "";
/*
concatenate the contents of then additional dom elements up to
the limit of description length
*/
$page_parts = ["/svg//desc", "/svg//text"];
foreach ($page_parts as $part) {
$doc_nodes = $xpath->evaluate($part);
foreach ($doc_nodes as $node) {
$description .= " ".$node->textContent;
if (strlen($description) > self::$max_description_len) {
break 2;
}
}
}
if (empty($description)) {
list(, $description) = parent::getBetweenTags($page, 0, "<desc",
"</desc");
return strip_tags("<desc" . $description . "</desc>");
}
if (empty($description)) {
list(, $description) = parent::getBetweenTags($page, 0, "<text",
"</text");
return strip_tags("<text" . $description . "</text>");
}
$description = mb_ereg_replace("(\s)+", " ", $description);
return $description;
}
}