includes/SearchEngine.php

   1 <?php
   2 /**
   3  * Contain a class for special pages
   4  * @package MediaWiki
   5  * @subpackage Search
   6  */
   7
   8 /**
   9  * @package MediaWiki
  10  */
  11 class SearchEngine {
  12         var $limit = 10;
  13         var $offset = 0;
  14         var $searchTerms = array();
  15         var $namespaces = array( 0 );
  16         var $showRedirects = false;
  17
  18         /**
  19          * Perform a full text search query and return a result set.
  20          * If title searches are not supported or disabled, return null.
  21          *
  22          * @param string $term - Raw search term
  23          * @return SearchResultSet
  24          * @access public
  25          * @abstract
  26          */
  27         function searchText( $term ) {
  28                 return null;
  29         }
  30
  31         /**
  32          * Perform a title-only search query and return a result set.
  33          * If title searches are not supported or disabled, return null.
  34          *
  35          * @param string $term - Raw search term
  36          * @return SearchResultSet
  37          * @access public
  38          * @abstract
  39          */
  40         function searchTitle( $term ) {
  41                 return null;
  42         }
  43
  44         /**
  45          * If an exact title match can be find, or a very slightly close match,
  46          * return the title. If no match, returns NULL.
  47          *
  48          * @static
  49          * @param string $term
  50          * @return Title
  51          * @access private
  52          */
  53         function getNearMatch( $term ) {
  54                 # Exact match? No need to look further.
  55                 $title = Title::newFromText( $term );
  56                 if (is_null($title))
  57                         return NULL;
  58
  59                 if ( $title->getNamespace() == NS_SPECIAL || $title->exists() ) {
  60                         return $title;
  61                 }
  62
  63                 # Now try all lower case (i.e. first letter capitalized)
  64                 #
  65                 $title = Title::newFromText( strtolower( $term ) );
  66                 if ( $title->exists() ) {
  67                         return $title;
  68                 }
  69
  70                 # Now try capitalized string
  71                 #
  72                 $title = Title::newFromText( ucwords( strtolower( $term ) ) );
  73                 if ( $title->exists() ) {
  74                         return $title;
  75                 }
  76
  77                 # Now try all upper case
  78                 #
  79                 $title = Title::newFromText( strtoupper( $term ) );
  80                 if ( $title->exists() ) {
  81                         return $title;
  82                 }
  83
  84                 global $wgCapitalLinks, $wgContLang;
  85                 if( !$wgCapitalLinks ) {
  86                         // Catch differs-by-first-letter-case-only
  87                         $title = Title::newFromText( $wgContLang->ucfirst( $term ) );
  88                         if ( $title->exists() ) {
  89                                 return $title;
  90                         }
  91                         $title = Title::newFromText( $wgContLang->lcfirst( $term ) );
  92                         if ( $title->exists() ) {
  93                                 return $title;
  94                         }
  95                 }
  96
  97                 $title = Title::newFromText( $term );
  98
  99                 # Entering an IP address goes to the contributions page
 100                 if ( ( $title->getNamespace() == NS_USER && User::isIP($title->getText() ) )
 101                         || User::isIP( trim( $term ) ) ) {
 102                         return Title::makeTitle( NS_SPECIAL, "Contributions/" . $title->getDbkey() );
 103                 }
 104
 105
 106                 # Entering a user goes to the user page whether it's there or not
 107                 if ( $title->getNamespace() == NS_USER ) {
 108                         return $title;
 109                 }
 110
 111                 # Quoted term? Try without the quotes...
 112                 if( preg_match( '/^"([^"]+)"$/', $term, $matches ) ) {
 113                         return SearchEngine::getNearMatch( $matches[1] );
 114                 }
 115
 116                 return NULL;
 117         }
 118
 119         function legalSearchChars() {
 120                 return "A-Za-z_'0-9\\x80-\\xFF\\-";
 121         }
 122
 123         /**
 124          * Set the maximum number of results to return
 125          * and how many to skip before returning the first.
 126          *
 127          * @param int $limit
 128          * @param int $offset
 129          * @access public
 130          */
 131         function setLimitOffset( $limit, $offset = 0 ) {
 132                 $this->limit = intval( $limit );
 133                 $this->offset = intval( $offset );
 134         }
 135
 136         /**
 137          * Set which namespaces the search should include.
 138          * Give an array of namespace index numbers.
 139          *
 140          * @param array $namespaces
 141          * @access public
 142          */
 143         function setNamespaces( $namespaces ) {
 144                 $this->namespaces = $namespaces;
 145         }
 146
 147         /**
 148          * Make a list of searchable namespaces and their canonical names.
 149          * @return array
 150          * @access public
 151          */
 152         function searchableNamespaces() {
 153                 global $wgContLang;
 154                 $arr = array();
 155                 foreach( $wgContLang->getNamespaces() as $ns => $name ) {
 156                         if( $ns >= NS_MAIN ) {
 157                                 $arr[$ns] = $name;
 158                         }
 159                 }
 160                 return $arr;
 161         }
 162
 163         /**
 164          * Return a 'cleaned up' search string
 165          *
 166          * @return string
 167          * @access public
 168          */
 169         function filter( $text ) {
 170                 $lc = $this->legalSearchChars();
 171                 return trim( preg_replace( "/[^{$lc}]/", " ", $text ) );
 172         }
 173         /**
 174          * Load up the appropriate search engine class for the currently
 175          * active database backend, and return a configured instance.
 176          *
 177          * @return SearchEngine
 178          * @access private
 179          */
 180         function create() {
 181                 global $wgDBtype, $wgSearchType;
 182                 if( $wgSearchType ) {
 183                         $class = $wgSearchType;
 184                 } elseif( $wgDBtype == 'mysql' ) {
 185                         $class = 'SearchMySQL4';
 186                         require_once( 'SearchMySQL4.php' );
 187                 } else if ( $wgDBtype == 'PostgreSQL' ) {
 188                         $class = 'SearchTsearch2';
 189                         require_once( 'SearchTsearch2.php' );
 190                 } else {
 191                         $class = 'SearchEngineDummy';
 192                 }
 193                 $search = new $class( wfGetDB( DB_SLAVE ) );
 194                 $search->setLimitOffset(0,0);
 195                 return $search;
 196         }
 197
 198         /**
 199          * Create or update the search index record for the given page.
 200          * Title and text should be pre-processed.
 201          *
 202          * @param int $id
 203          * @param string $title
 204          * @param string $text
 205          * @abstract
 206          */
 207         function update( $id, $title, $text ) {
 208                 // no-op
 209         }
 210
 211         /**
 212          * Update a search index record's title only.
 213          * Title should be pre-processed.
 214          *
 215          * @param int $id
 216          * @param string $title
 217          * @abstract
 218          */
 219     function updateTitle( $id, $title ) {
 220                 // no-op
 221     }
 222 }
 223
 224 /** @package MediaWiki */
 225 class SearchResultSet {
 226         /**
 227          * Fetch an array of regular expression fragments for matching
 228          * the search terms as parsed by this engine in a text extract.
 229          *
 230          * @return array
 231          * @access public
 232          * @abstract
 233          */
 234         function termMatches() {
 235                 return array();
 236         }
 237
 238         function numRows() {
 239                 return 0;
 240         }
 241
 242         /**
 243          * Return true if results are included in this result set.
 244          * @return bool
 245          * @abstract
 246          */
 247         function hasResults() {
 248                 return false;
 249         }
 250
 251         /**
 252          * Some search modes return a total hit count for the query
 253          * in the entire article database. This may include pages
 254          * in namespaces that would not be matched on the given
 255          * settings.
 256          *
 257          * Return null if no total hits number is supported.
 258          *
 259          * @return int
 260          * @access public
 261          */
 262         function getTotalHits() {
 263                 return null;
 264         }
 265
 266         /**
 267          * Some search modes return a suggested alternate term if there are
 268          * no exact hits. Returns true if there is one on this set.
 269          *
 270          * @return bool
 271          * @access public
 272          */
 273         function hasSuggestion() {
 274                 return false;
 275         }
 276
 277         /**
 278          * Some search modes return a suggested alternate term if there are
 279          * no exact hits. Check hasSuggestion() first.
 280          *
 281          * @return string
 282          * @access public
 283          */
 284         function getSuggestion() {
 285                 return '';
 286         }
 287
 288         /**
 289          * Fetches next search result, or false.
 290          * @return SearchResult
 291          * @access public
 292          * @abstract
 293          */
 294         function next() {
 295                 return false;
 296         }
 297 }
 298
 299 /** @package MediaWiki */
 300 class SearchResult {
 301         function SearchResult( $row ) {
 302                 $this->mTitle = Title::makeTitle( $row->page_namespace, $row->page_title );
 303         }
 304
 305         /**
 306          * @return Title
 307          * @access public
 308          */
 309         function getTitle() {
 310                 return $this->mTitle;
 311         }
 312
 313         /**
 314          * @return double or null if not supported
 315          */
 316         function getScore() {
 317                 return null;
 318         }
 319 }
 320
 321 /**
 322  * @package MediaWiki
 323  */
 324 class SearchEngineDummy {
 325         function search( $term ) {
 326                 return null;
 327         }
 328         function setLimitOffset($l, $o) {}
 329         function legalSearchChars() {}
 330         function update() {}
 331         function setnamespaces() {}
 332         function searchtitle() {}
 333         function searchtext() {}
 334 }
 335