application/LinkFilter.php

   1 <?php
   2
   3 /**
   4  * Class LinkFilter.
   5  *
   6  * Perform search and filter operation on link data list.
   7  */
   8 class LinkFilter
   9 {
  10     /**
  11      * @var string permalinks.
  12      */
  13     public static $FILTER_HASH   = 'permalink';
  14
  15     /**
  16      * @var string text search.
  17      */
  18     public static $FILTER_TEXT   = 'fulltext';
  19
  20     /**
  21      * @var string tag filter.
  22      */
  23     public static $FILTER_TAG    = 'tags';
  24
  25     /**
  26      * @var string filter by day.
  27      */
  28     public static $FILTER_DAY    = 'FILTER_DAY';
  29
  30     /**
  31      * @var array all available links.
  32      */
  33     private $links;
  34
  35     /**
  36      * @param array $links initialization.
  37      */
  38     public function __construct($links)
  39     {
  40         $this->links = $links;
  41     }
  42
  43     /**
  44      * Filter links according to parameters.
  45      *
  46      * @param string $type          Type of filter (eg. tags, permalink, etc.).
  47      * @param string $request       Filter content.
  48      * @param bool   $casesensitive Optional: Perform case sensitive filter if true.
  49      * @param bool   $privateonly   Optional: Only returns private links if true.
  50      *
  51      * @return array filtered link list.
  52      */
  53     public function filter($type, $request, $casesensitive = false, $privateonly = false)
  54     {
  55         switch($type) {
  56             case self::$FILTER_HASH:
  57                 return $this->filterSmallHash($request);
  58                 break;
  59             case self::$FILTER_TEXT:
  60                 return $this->filterFulltext($request, $privateonly);
  61                 break;
  62             case self::$FILTER_TAG:
  63                 return $this->filterTags($request, $casesensitive, $privateonly);
  64                 break;
  65             case self::$FILTER_DAY:
  66                 return $this->filterDay($request);
  67                 break;
  68             default:
  69                 return $this->noFilter($privateonly);
  70         }
  71     }
  72
  73     /**
  74      * Unknown filter, but handle private only.
  75      *
  76      * @param bool $privateonly returns private link only if true.
  77      *
  78      * @return array filtered links.
  79      */
  80     private function noFilter($privateonly = false)
  81     {
  82         if (! $privateonly) {
  83             krsort($this->links);
  84             return $this->links;
  85         }
  86
  87         $out = array();
  88         foreach ($this->links as $value) {
  89             if ($value['private']) {
  90                 $out[$value['linkdate']] = $value;
  91             }
  92         }
  93
  94         krsort($out);
  95         return $out;
  96     }
  97
  98     /**
  99      * Returns the shaare corresponding to a smallHash.
 100      *
 101      * @param string $smallHash permalink hash.
 102      *
 103      * @return array $filtered array containing permalink data.
 104      */
 105     private function filterSmallHash($smallHash)
 106     {
 107         $filtered = array();
 108         foreach ($this->links as $l) {
 109             if ($smallHash == smallHash($l['linkdate'])) {
 110                 // Yes, this is ugly and slow
 111                 $filtered[$l['linkdate']] = $l;
 112                 return $filtered;
 113             }
 114         }
 115         return $filtered;
 116     }
 117
 118     /**
 119      * Returns the list of links corresponding to a full-text search
 120      *
 121      * Searches:
 122      *  - in the URLs, title and description;
 123      *  - are case-insensitive.
 124      *
 125      * Example:
 126      *    print_r($mydb->filterFulltext('hollandais'));
 127      *
 128      * mb_convert_case($val, MB_CASE_LOWER, 'UTF-8')
 129      *  - allows to perform searches on Unicode text
 130      *  - see https://github.com/shaarli/Shaarli/issues/75 for examples
 131      *
 132      * @param string $searchterms search query.
 133      * @param bool   $privateonly return only private links if true.
 134      *
 135      * @return array search results.
 136      */
 137     private function filterFulltext($searchterms, $privateonly = false)
 138     {
 139         // FIXME: explode(' ',$searchterms) and perform a AND search.
 140         // FIXME: accept double-quotes to search for a string "as is"?
 141         $filtered = array();
 142         $search = mb_convert_case($searchterms, MB_CASE_LOWER, 'UTF-8');
 143         $explodedSearch = explode(' ', trim($search));
 144         $keys = array('title', 'description', 'url', 'tags');
 145
 146         // Iterate over every stored link.
 147         foreach ($this->links as $link) {
 148             $found = false;
 149
 150             // ignore non private links when 'privatonly' is on.
 151             if (! $link['private'] && $privateonly === true) {
 152                 continue;
 153             }
 154
 155             // Iterate over searchable link fields.
 156             foreach ($keys as $key) {
 157                 // Search full expression.
 158                 if (strpos(
 159                     mb_convert_case($link[$key], MB_CASE_LOWER, 'UTF-8'),
 160                     $search
 161                 ) !== false) {
 162                     $found = true;
 163                 }
 164
 165                 if ($found) {
 166                     break;
 167                 }
 168             }
 169
 170             if ($found) {
 171                 $filtered[$link['linkdate']] = $link;
 172             }
 173         }
 174
 175         krsort($filtered);
 176         return $filtered;
 177     }
 178
 179     /**
 180      * Returns the list of links associated with a given list of tags
 181      *
 182      * You can specify one or more tags, separated by space or a comma, e.g.
 183      *  print_r($mydb->filterTags('linux programming'));
 184      *
 185      * @param string $tags          list of tags separated by commas or blank spaces.
 186      * @param bool   $casesensitive ignore case if false.
 187      * @param bool   $privateonly   returns private links only.
 188      *
 189      * @return array filtered links.
 190      */
 191     public function filterTags($tags, $casesensitive = false, $privateonly = false)
 192     {
 193         $searchtags = $this->tagsStrToArray($tags, $casesensitive);
 194         $filtered = array();
 195
 196         foreach ($this->links as $l) {
 197             // ignore non private links when 'privatonly' is on.
 198             if (! $l['private'] && $privateonly === true) {
 199                 continue;
 200             }
 201
 202             $linktags = $this->tagsStrToArray($l['tags'], $casesensitive);
 203
 204             if (count(array_intersect($linktags, $searchtags)) == count($searchtags)) {
 205                 $filtered[$l['linkdate']] = $l;
 206             }
 207         }
 208         krsort($filtered);
 209         return $filtered;
 210     }
 211
 212     /**
 213      * Returns the list of articles for a given day, chronologically sorted
 214      *
 215      * Day must be in the form 'YYYYMMDD' (e.g. '20120125'), e.g.
 216      *  print_r($mydb->filterDay('20120125'));
 217      *
 218      * @param string $day day to filter.
 219      *
 220      * @return array all link matching given day.
 221      *
 222      * @throws Exception if date format is invalid.
 223      */
 224     public function filterDay($day)
 225     {
 226         if (! checkDateFormat('Ymd', $day)) {
 227             throw new Exception('Invalid date format');
 228         }
 229
 230         $filtered = array();
 231         foreach ($this->links as $l) {
 232             if (startsWith($l['linkdate'], $day)) {
 233                 $filtered[$l['linkdate']] = $l;
 234             }
 235         }
 236         ksort($filtered);
 237         return $filtered;
 238     }
 239
 240     /**
 241      * Convert a list of tags (str) to an array. Also
 242      * - handle case sensitivity.
 243      * - accepts spaces commas as separator.
 244      * - remove private tags for loggedout users.
 245      *
 246      * @param string $tags          string containing a list of tags.
 247      * @param bool   $casesensitive will convert everything to lowercase if false.
 248      *
 249      * @return array filtered tags string.
 250     */
 251     public function tagsStrToArray($tags, $casesensitive)
 252     {
 253         // We use UTF-8 conversion to handle various graphemes (i.e. cyrillic, or greek)
 254         $tagsOut = $casesensitive ? $tags : mb_convert_case($tags, MB_CASE_LOWER, 'UTF-8');
 255         $tagsOut = str_replace(',', ' ', $tagsOut);
 256
 257         return explode(' ', trim($tagsOut));
 258     }
 259 }