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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 LinkDB all available links.
- */
- private $links;
- /**
- * @param LinkDB $links initialization.
- */
- public function __construct($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 string $visibility Optional: return only all/private/public links
- * @param string $untaggedonly Optional: return only untagged links. Applies only if $type includes FILTER_TAG
- *
- * @return array filtered link list.
- */
- public function filter($type, $request, $casesensitive = false, $visibility = 'all', $untaggedonly = false)
- {
- if (! in_array($visibility, ['all', 'public', 'private'])) {
- $visibility = 'all';
- }
- switch($type) {
- case self::$FILTER_HASH:
- return $this->filterSmallHash($request);
- case self::$FILTER_TAG | self::$FILTER_TEXT: // == "vuotext"
- $noRequest = empty($request) || (empty($request[0]) && empty($request[1]));
- if ($noRequest) {
- if ($untaggedonly) {
- return $this->filterUntagged($visibility);
- }
- return $this->noFilter($visibility);
- }
- if ($untaggedonly) {
- $filtered = $this->filterUntagged($visibility);
- } else {
- $filtered = $this->links;
- }
- if (!empty($request[0])) {
- $filtered = (new LinkFilter($filtered))->filterTags($request[0], $casesensitive, $visibility);
- }
- if (!empty($request[1])) {
- $filtered = (new LinkFilter($filtered))->filterFulltext($request[1], $visibility);
- }
- return $filtered;
- case self::$FILTER_TEXT:
- return $this->filterFulltext($request, $visibility);
- case self::$FILTER_TAG:
- if ($untaggedonly) {
- return $this->filterUntagged($visibility);
- } else {
- return $this->filterTags($request, $casesensitive, $visibility);
- }
- case self::$FILTER_DAY:
- return $this->filterDay($request);
- default:
- return $this->noFilter($visibility);
- }
- }
- /**
- * Unknown filter, but handle private only.
- *
- * @param string $visibility Optional: return only all/private/public links
- *
- * @return array filtered links.
- */
- private function noFilter($visibility = 'all')
- {
- if ($visibility === 'all') {
- return $this->links;
- }
- $out = array();
- foreach ($this->links as $key => $value) {
- if ($value['private'] && $visibility === 'private') {
- $out[$key] = $value;
- } else if (! $value['private'] && $visibility === 'public') {
- $out[$key] = $value;
- }
- }
- 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 $key => $l) {
- if ($smallHash == $l['shorturl']) {
- // Yes, this is ugly and slow
- $filtered[$key] = $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 string $visibility Optional: return only all/private/public links.
- *
- * @return array search results.
- */
- private function filterFulltext($searchterms, $visibility = 'all')
- {
- if (empty($searchterms)) {
- return $this->noFilter($visibility);
- }
- $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 $id => $link) {
- // ignore non private links when 'privatonly' is on.
- if ($visibility !== 'all') {
- if (! $link['private'] && $visibility === 'private') {
- continue;
- } else if ($link['private'] && $visibility === 'public') {
- 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) {
- $filtered[$id] = $link;
- }
- }
- return $filtered;
- }
- /**
- * generate a regex fragment out of a tag
- * @param string $tag to to generate regexs from. may start with '-' to negate, contain '*' as wildcard
- * @return string generated regex fragment
- */
- private static function tag2regex($tag)
- {
- $len = strlen($tag);
- if(!$len || $tag === "-" || $tag === "*"){
- // nothing to search, return empty regex
- return '';
- }
- if($tag[0] === "-") {
- // query is negated
- $i = 1; // use offset to start after '-' character
- $regex = '(?!'; // create negative lookahead
- } else {
- $i = 0; // start at first character
- $regex = '(?='; // use positive lookahead
- }
- $regex .= '.*(?:^| )'; // before tag may only be a space or the beginning
- // iterate over string, separating it into placeholder and content
- for(; $i < $len; $i++){
- if($tag[$i] === '*'){
- // placeholder found
- $regex .= '[^ ]*?';
- } else {
- // regular characters
- $offset = strpos($tag, '*', $i);
- if($offset === false){
- // no placeholder found, set offset to end of string
- $offset = $len;
- }
- // subtract one, as we want to get before the placeholder or end of string
- $offset -= 1;
- // we got a tag name that we want to search for. escape any regex characters to prevent conflicts.
- $regex .= preg_quote(substr($tag, $i, $offset - $i + 1), '/');
- // move $i on
- $i = $offset;
- }
- }
- $regex .= '(?:$| ))'; // after the tag may only be a space or the end
- return $regex;
- }
- /**
- * Returns the list of links associated with a given list of tags
- *
- * You can specify one or more tags, separated by space or a comma, e.g.
- * print_r($mydb->filterTags('linux programming'));
- *
- * @param string $tags list of tags separated by commas or blank spaces.
- * @param bool $casesensitive ignore case if false.
- * @param string $visibility Optional: return only all/private/public links.
- *
- * @return array filtered links.
- */
- public function filterTags($tags, $casesensitive = false, $visibility = 'all')
- {
- // get single tags (we may get passed an array, even though the docs say different)
- $inputTags = $tags;
- if(!is_array($tags)) {
- // we got an input string, split tags
- $inputTags = preg_split('/(?:\s+)|,/', $inputTags, -1, PREG_SPLIT_NO_EMPTY);
- }
- if(!count($inputTags)){
- // no input tags
- return $this->noFilter($visibility);
- }
- // build regex from all tags
- $re = '/^' . implode(array_map("self::tag2regex", $inputTags)) . '.*$/';
- if(!$casesensitive) {
- // make regex case insensitive
- $re .= 'i';
- }
- // create resulting array
- $filtered = array();
- // iterate over each link
- foreach ($this->links as $key => $link) {
- // check level of visibility
- // ignore non private links when 'privateonly' is on.
- if ($visibility !== 'all') {
- if (! $link['private'] && $visibility === 'private') {
- continue;
- } else if ($link['private'] && $visibility === 'public') {
- continue;
- }
- }
- $search = $link['tags']; // build search string, start with tags of current link
- if(strlen(trim($link['description'])) && strpos($link['description'], '#') !== false){
- // description given and at least one possible tag found
- $descTags = array();
- // find all tags in the form of #tag in the description
- preg_match_all(
- '/(?<![' . self::$HASHTAG_CHARS . '])#([' . self::$HASHTAG_CHARS . ']+?)\b/sm',
- $link['description'],
- $descTags
- );
- if(count($descTags[1])){
- // there were some tags in the description, add them to the search string
- $search .= ' ' . implode(' ', $descTags[1]);
- }
- };
- // match regular expression with search string
- if(!preg_match($re, $search)){
- // this entry does _not_ match our regex
- continue;
- }
- $filtered[$key] = $link;
- }
- return $filtered;
- }
- /**
- * Return only links without any tag.
- *
- * @param string $visibility return only all/private/public links.
- *
- * @return array filtered links.
- */
- public function filterUntagged($visibility)
- {
- $filtered = [];
- foreach ($this->links as $key => $link) {
- if ($visibility !== 'all') {
- if (! $link['private'] && $visibility === 'private') {
- continue;
- } else if ($link['private'] && $visibility === 'public') {
- continue;
- }
- }
- if (empty(trim($link['tags']))) {
- $filtered[$key] = $link;
- }
- }
- 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 $key => $l) {
- if ($l['created']->format('Ymd') == $day) {
- $filtered[$key] = $l;
- }
- }
- // sort by date ASC
- return array_reverse($filtered, true);
- }
- /**
- * 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 preg_split('/\s+/', $tagsOut, -1, PREG_SPLIT_NO_EMPTY);
- }
- }
- class LinkNotFoundException extends Exception
- {
- /**
- * LinkNotFoundException constructor.
- */
- public function __construct()
- {
- $this->message = t('The link you are trying to reach does not exist or has been deleted.');
- }
- }
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