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- <?php
- /**
- * Class LinkFilter.
- *
- * Perform search and filter operation on link data list.
- */
- class LinkFilter
- {
- /**
- * @var string permalinks.
- */
- public static $FILTER_HASH = 'permalink';
- /**
- * @var string text search.
- */
- public static $FILTER_TEXT = 'fulltext';
- /**
- * @var string tag filter.
- */
- public static $FILTER_TAG = 'tags';
- /**
- * @var string filter by day.
- */
- public static $FILTER_DAY = 'FILTER_DAY';
- /**
- * @var string Allowed characters for hashtags (regex syntax).
- */
- public static $HASHTAG_CHARS = '\p{Pc}\p{N}\p{L}\p{Mn}';
- /**
- * @var array all available links.
- */
- private $links;
- /**
- * @param array $links initialization.
- */
- public function __construct($links)
- {
- $this->links = $links;
- }
- /**
- * Filter links according to parameters.
- *
- * @param string $type Type of filter (eg. tags, permalink, etc.).
- * @param mixed $request Filter content.
- * @param bool $casesensitive Optional: Perform case sensitive filter if true.
- * @param bool $privateonly Optional: Only returns private links if true.
- *
- * @return array filtered link list.
- */
- public function filter($type, $request, $casesensitive = false, $privateonly = false)
- {
- switch($type) {
- case self::$FILTER_HASH:
- return $this->filterSmallHash($request);
- case self::$FILTER_TAG | self::$FILTER_TEXT:
- if (!empty($request)) {
- $filtered = $this->links;
- if (isset($request[0])) {
- $filtered = $this->filterTags($request[0], $casesensitive, $privateonly);
- }
- if (isset($request[1])) {
- $lf = new LinkFilter($filtered);
- $filtered = $lf->filterFulltext($request[1], $privateonly);
- }
- return $filtered;
- }
- return $this->noFilter($privateonly);
- case self::$FILTER_TEXT:
- return $this->filterFulltext($request, $privateonly);
- case self::$FILTER_TAG:
- return $this->filterTags($request, $casesensitive, $privateonly);
- case self::$FILTER_DAY:
- return $this->filterDay($request);
- default:
- return $this->noFilter($privateonly);
- }
- }
- /**
- * Unknown filter, but handle private only.
- *
- * @param bool $privateonly returns private link only if true.
- *
- * @return array filtered links.
- */
- private function noFilter($privateonly = false)
- {
- if (! $privateonly) {
- krsort($this->links);
- return $this->links;
- }
- $out = array();
- foreach ($this->links as $value) {
- if ($value['private']) {
- $out[$value['linkdate']] = $value;
- }
- }
- krsort($out);
- return $out;
- }
- /**
- * Returns the shaare corresponding to a smallHash.
- *
- * @param string $smallHash permalink hash.
- *
- * @return array $filtered array containing permalink data.
- *
- * @throws LinkNotFoundException if the smallhash doesn't match any link.
- */
- private function filterSmallHash($smallHash)
- {
- $filtered = array();
- foreach ($this->links as $l) {
- if ($smallHash == smallHash($l['linkdate'])) {
- // Yes, this is ugly and slow
- $filtered[$l['linkdate']] = $l;
- return $filtered;
- }
- }
- if (empty($filtered)) {
- throw new LinkNotFoundException();
- }
- return $filtered;
- }
- /**
- * Returns the list of links corresponding to a full-text search
- *
- * Searches:
- * - in the URLs, title and description;
- * - are case-insensitive;
- * - terms surrounded by quotes " are exact terms search.
- * - terms starting with a dash - are excluded (except exact terms).
- *
- * Example:
- * print_r($mydb->filterFulltext('hollandais'));
- *
- * mb_convert_case($val, MB_CASE_LOWER, 'UTF-8')
- * - allows to perform searches on Unicode text
- * - see https://github.com/shaarli/Shaarli/issues/75 for examples
- *
- * @param string $searchterms search query.
- * @param bool $privateonly return only private links if true.
- *
- * @return array search results.
- */
- private function filterFulltext($searchterms, $privateonly = false)
- {
- if (empty($searchterms)) {
- return $this->links;
- }
- $filtered = array();
- $search = mb_convert_case(html_entity_decode($searchterms), MB_CASE_LOWER, 'UTF-8');
- $exactRegex = '/"([^"]+)"/';
- // Retrieve exact search terms.
- preg_match_all($exactRegex, $search, $exactSearch);
- $exactSearch = array_values(array_filter($exactSearch[1]));
- // Remove exact search terms to get AND terms search.
- $explodedSearchAnd = explode(' ', trim(preg_replace($exactRegex, '', $search)));
- $explodedSearchAnd = array_values(array_filter($explodedSearchAnd));
- // Filter excluding terms and update andSearch.
- $excludeSearch = array();
- $andSearch = array();
- foreach ($explodedSearchAnd as $needle) {
- if ($needle[0] == '-' && strlen($needle) > 1) {
- $excludeSearch[] = substr($needle, 1);
- } else {
- $andSearch[] = $needle;
- }
- }
- $keys = array('title', 'description', 'url', 'tags');
- // Iterate over every stored link.
- foreach ($this->links as $link) {
- // ignore non private links when 'privatonly' is on.
- if (! $link['private'] && $privateonly === true) {
- continue;
- }
- // Concatenate link fields to search across fields.
- // Adds a '\' separator for exact search terms.
- $content = '';
- foreach ($keys as $key) {
- $content .= mb_convert_case($link[$key], MB_CASE_LOWER, 'UTF-8') . '\\';
- }
- // Be optimistic
- $found = true;
- // First, we look for exact term search
- for ($i = 0; $i < count($exactSearch) && $found; $i++) {
- $found = strpos($content, $exactSearch[$i]) !== false;
- }
- // Iterate over keywords, if keyword is not found,
- // no need to check for the others. We want all or nothing.
- for ($i = 0; $i < count($andSearch) && $found; $i++) {
- $found = strpos($content, $andSearch[$i]) !== false;
- }
- // Exclude terms.
- for ($i = 0; $i < count($excludeSearch) && $found; $i++) {
- $found = strpos($content, $excludeSearch[$i]) === false;
- }
- if ($found) {
- $filtered[$link['linkdate']] = $link;
- }
- }
- krsort($filtered);
- return $filtered;
- }
- /**
- * Returns the list of links associated with a given list of tags
- *
- * You can specify one or more tags, separated by space or a comma, e.g.
- * print_r($mydb->filterTags('linux programming'));
- *
- * @param string $tags list of tags separated by commas or blank spaces.
- * @param bool $casesensitive ignore case if false.
- * @param bool $privateonly returns private links only.
- *
- * @return array filtered links.
- */
- public function filterTags($tags, $casesensitive = false, $privateonly = false)
- {
- // Implode if array for clean up.
- $tags = is_array($tags) ? trim(implode(' ', $tags)) : $tags;
- if (empty($tags)) {
- return $this->links;
- }
- $searchtags = self::tagsStrToArray($tags, $casesensitive);
- $filtered = array();
- if (empty($searchtags)) {
- return $filtered;
- }
- foreach ($this->links as $link) {
- // ignore non private links when 'privatonly' is on.
- if (! $link['private'] && $privateonly === true) {
- continue;
- }
- $linktags = self::tagsStrToArray($link['tags'], $casesensitive);
- $found = true;
- for ($i = 0 ; $i < count($searchtags) && $found; $i++) {
- // Exclusive search, quit if tag found.
- // Or, tag not found in the link, quit.
- if (($searchtags[$i][0] == '-'
- && $this->searchTagAndHashTag(substr($searchtags[$i], 1), $linktags, $link['description']))
- || ($searchtags[$i][0] != '-')
- && ! $this->searchTagAndHashTag($searchtags[$i], $linktags, $link['description'])
- ) {
- $found = false;
- }
- }
- if ($found) {
- $filtered[$link['linkdate']] = $link;
- }
- }
- krsort($filtered);
- return $filtered;
- }
- /**
- * Returns the list of articles for a given day, chronologically sorted
- *
- * Day must be in the form 'YYYYMMDD' (e.g. '20120125'), e.g.
- * print_r($mydb->filterDay('20120125'));
- *
- * @param string $day day to filter.
- *
- * @return array all link matching given day.
- *
- * @throws Exception if date format is invalid.
- */
- public function filterDay($day)
- {
- if (! checkDateFormat('Ymd', $day)) {
- throw new Exception('Invalid date format');
- }
- $filtered = array();
- foreach ($this->links as $l) {
- if (startsWith($l['linkdate'], $day)) {
- $filtered[$l['linkdate']] = $l;
- }
- }
- ksort($filtered);
- return $filtered;
- }
- /**
- * Check if a tag is found in the taglist, or as an hashtag in the link description.
- *
- * @param string $tag Tag to search.
- * @param array $taglist List of tags for the current link.
- * @param string $description Link description.
- *
- * @return bool True if found, false otherwise.
- */
- protected function searchTagAndHashTag($tag, $taglist, $description)
- {
- if (in_array($tag, $taglist)) {
- return true;
- }
- if (preg_match('/(^| )#'. $tag .'([^'. self::$HASHTAG_CHARS .']|$)/mui', $description) > 0) {
- return true;
- }
- return false;
- }
- /**
- * Convert a list of tags (str) to an array. Also
- * - handle case sensitivity.
- * - accepts spaces commas as separator.
- *
- * @param string $tags string containing a list of tags.
- * @param bool $casesensitive will convert everything to lowercase if false.
- *
- * @return array filtered tags string.
- */
- public static function tagsStrToArray($tags, $casesensitive)
- {
- // We use UTF-8 conversion to handle various graphemes (i.e. cyrillic, or greek)
- $tagsOut = $casesensitive ? $tags : mb_convert_case($tags, MB_CASE_LOWER, 'UTF-8');
- $tagsOut = str_replace(',', ' ', $tagsOut);
- return array_values(array_filter(explode(' ', trim($tagsOut)), 'strlen'));
- }
- }
- class LinkNotFoundException extends Exception
- {
- protected $message = 'The link you are trying to reach does not exist or has been deleted.';
- }
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