includes/SearchEngine.php

   1 <?php
   2 /**
   3  * Contain a class for special pages
   4  * @package MediaWiki
   5  */
   6
   7 /**
   8  * @package MediaWiki
   9  */
  10 class SearchEngine {
  11         var $limit = 10;
  12         var $offset = 0;
  13         var $searchTerms = array();
  14         var $namespaces = array( 0 );
  15         var $showRedirects = false;
  16
  17         /**
  18          * Perform a full text search query and return a result set.
  19          *
  20          * @param string $term - Raw search term
  21          * @param array $namespaces - List of namespaces to search
  22          * @return ResultWrapper
  23          * @access public
  24          */
  25         function searchText( $term ) {
  26                 return $this->db->resultObject( $this->db->query( $this->getQuery( $this->filter( $term ), true ) ) );
  27         }
  28
  29         /**
  30          * Perform a title-only search query and return a result set.
  31          *
  32          * @param string $term - Raw search term
  33          * @param array $namespaces - List of namespaces to search
  34          * @return ResultWrapper
  35          * @access public
  36          */
  37         function searchTitle( $term ) {
  38                 return $this->db->resultObject( $this->db->query( $this->getQuery( $this->filter( $term ), false ) ) );
  39         }
  40
  41         /**
  42          * If an exact title match can be find, or a very slightly close match,
  43          * return the title. If no match, returns NULL.
  44          *
  45          * @param string $term
  46          * @return Title
  47          * @access private
  48          */
  49         function getNearMatch( $term ) {
  50                 # Exact match? No need to look further.
  51                 $title = Title::newFromText( $term );
  52                 if ( $title->getNamespace() == NS_SPECIAL || 0 != $title->getArticleID() ) {
  53                         return $title;
  54                 }
  55
  56                 # Now try all lower case (i.e. first letter capitalized)
  57                 #
  58                 $title = Title::newFromText( strtolower( $term ) );
  59                 if ( 0 != $title->getArticleID() ) {
  60                         return $title;
  61                 }
  62
  63                 # Now try capitalized string
  64                 #
  65                 $title = Title::newFromText( ucwords( strtolower( $term ) ) );
  66                 if ( 0 != $title->getArticleID() ) {
  67                         return $title;
  68                 }
  69
  70                 # Now try all upper case
  71                 #
  72                 $title = Title::newFromText( strtoupper( $term ) );
  73                 if ( 0 != $title->getArticleID() ) {
  74                         return $title;
  75                 }
  76
  77                 $title = Title::newFromText( $term );
  78
  79                 # Entering an IP address goes to the contributions page
  80                 if ( ( $title->getNamespace() == NS_USER && User::isIP($title->getText() ) )
  81                         || User::isIP( trim( $term ) ) ) {
  82                         return Title::makeTitle( NS_SPECIAL, "Contributions/" . $title->getDbkey() );
  83                 }
  84
  85
  86                 # Entering a user goes to the user page whether it's there or not
  87                 if ( $title->getNamespace() == NS_USER ) {
  88                         return $title;
  89                 }
  90
  91                 return NULL;
  92         }
  93
  94         function legalSearchChars() {
  95                 return "A-Za-z_'0-9\\x80-\\xFF\\-";
  96         }
  97
  98         /**
  99          * Set the maximum number of results to return
 100          * and how many to skip before returning the first.
 101          *
 102          * @param int $limit
 103          * @param int $offset
 104          * @access public
 105          */
 106         function setLimitOffset( $limit, $offset = 0 ) {
 107                 $this->limit = IntVal( $limit );
 108                 $this->offset = IntVal( $offset );
 109         }
 110
 111         /**
 112          * Set which namespaces the search should include.
 113          * Give an array of namespace index numbers.
 114          *
 115          * @param array $namespaces
 116          * @access public
 117          */
 118         function setNamespaces( $namespaces ) {
 119                 $this->namespaces = $namespaces;
 120         }
 121
 122         /**
 123          * Make a list of searchable namespaces and their canonical names.
 124          * @return array
 125          * @access public
 126          */
 127         function searchableNamespaces() {
 128                 global $wgContLang;
 129                 $arr = array();
 130                 foreach( $wgContLang->getNamespaces() as $ns => $name ) {
 131                         if( $ns >= NS_MAIN ) {
 132                                 $arr[$ns] = $name;
 133                         }
 134                 }
 135                 return $arr;
 136         }
 137
 138         /**
 139          * Fetch an array of regular expression fragments for matching
 140          * the search terms as parsed by this engine in a text extract.
 141          *
 142          * @return array
 143          * @access public
 144          */
 145         function termMatches() {
 146                 return $this->searchTerms;
 147         }
 148
 149         /**
 150          * Return a 'cleaned up' search string
 151          *
 152          * @return string
 153          * @access public
 154          */
 155         function filter( $text ) {
 156                 $lc = $this->legalSearchChars();
 157                 return trim( preg_replace( "/[^{$lc}]/", " ", $text ) );
 158         }
 159
 160         /**
 161          * Return a partial WHERE clause to exclude redirects, if so set
 162          * @return string
 163          * @access private
 164          */
 165         function queryRedirect() {
 166                 if( $this->showRedirects ) {
 167                         return 'AND cur_is_redirect=0';
 168                 } else {
 169                         return '';
 170                 }
 171         }
 172
 173         /**
 174          * Return a partial WHERE clause to limit the search to the given namespaces
 175          * @return string
 176          * @access private
 177          */
 178         function queryNamespaces() {
 179                 $namespaces = implode( ',', $this->namespaces );
 180                 if ($namespaces == '') {
 181                         $namespaces = '0';
 182                 }
 183                 return 'AND page_namespace IN (' . $namespaces . ')';
 184         }
 185
 186         /**
 187          * Return a LIMIT clause to limit results on the query.
 188          * @return string
 189          * @access private
 190          */
 191         function queryLimit() {
 192                 return $this->db->limitResult( $this->limit, $this->offset );
 193         }
 194
 195         /**
 196          * Does not do anything for generic search engine
 197          * subclasses may define this though
 198          * @return string
 199          * @access private
 200          */
 201         function queryRanking($filteredTerm,$fulltext) {
 202                 return "";
 203         }
 204
 205         /**
 206          * Construct the full SQL query to do the search.
 207          * The guts shoulds be constructed in queryMain()
 208          * @param string $filteredTerm
 209          * @param bool $fulltext
 210          * @access private
 211          */
 212         function getQuery( $filteredTerm, $fulltext ) {
 213                 return $this->queryMain( $filteredTerm, $fulltext ) . ' ' .
 214                         $this->queryRedirect() . ' ' .
 215                         $this->queryNamespaces() . ' ' .
 216                         $this->queryRanking($filteredTerm, $fulltext) . ' ' .
 217                         $this->queryLimit();
 218         }
 219
 220         /**
 221          * Load up the appropriate search engine class for the currently
 222            * active database backend, and return a configured instance.
 223            *
 224            * @return SearchEngine
 225            * @access private
 226         */
 227         function create() {
 228                 global $wgDBtype, $wgDBmysql4, $wgSearchType;
 229                 if( $wgDBtype == 'mysql' ) {
 230                         if( $wgDBmysql4 ) {
 231                                 $class = 'SearchMySQL4';
 232                                 require_once( 'SearchMySQL4.php' );
 233                         } else {
 234                                 $class = 'SearchMysql3';
 235                                 require_once( 'SearchMySQL3.php' );
 236                         }
 237                 } else if ( $wgDBtype == 'PostgreSQL' ) {
 238                         $class = 'SearchTsearch2';
 239                         require_once( 'SearchTsearch2.php' );
 240                 } else {
 241                         $class = 'SearchEngineDummy';
 242                 }
 243                 $search = new $class( wfGetDB( DB_SLAVE ) );
 244                 $search->setLimitOffset(0,0);
 245                 return $search;
 246         }
 247
 248
 249 }
 250
 251 /**
 252  * @package MediaWiki
 253  */
 254 class SearchEngineDummy {
 255         function search( $term ) {
 256                 return null;
 257         }
 258 }
 259