*/
/**
- * Main execution point
- * @param $par Namespace to select the page from
+ * Special page to direct the user to a random page
+ *
+ * @addtogroup SpecialPage
*/
-function wfSpecialRandompage( $par = null ) {
- global $wgOut, $wgContLang;
-
- $rnd = new RandomPage();
- $rnd->setNamespace( $wgContLang->getNsIndex( $par ) );
- $rnd->setRedirect( false );
-
- $title = $rnd->getRandomTitle();
+class RandomPage extends SpecialPage {
+ private $namespace = NS_MAIN; // namespace to select pages from
- if( is_null( $title ) ) {
- $wgOut->addWikiText( wfMsg( 'randompage-nopages' ) );
- return;
+ function __construct( $name = 'Randompage' ){
+ parent::__construct( $name );
}
- $wgOut->reportTime();
- $wgOut->redirect( $title->getFullUrl() );
-}
-
-
-class RandomPage {
- private $namespace = NS_MAIN; // namespace to select pages from
- private $redirect = false; // select redirects instead of normal pages?
-
- public function getNamespace ( ) {
+ public function getNamespace() {
return $this->namespace;
}
+
public function setNamespace ( $ns ) {
if( $ns < NS_MAIN ) $ns = NS_MAIN;
$this->namespace = $ns;
}
- public function getRedirect ( ) {
- return $this->redirect;
+
+ // select redirects instead of normal pages?
+ // Overriden by SpecialRandomredirect
+ public function isRedirect(){
+ return false;
}
- public function setRedirect ( $redirect ) {
- $this->redirect = $redirect;
+
+ public function execute( $par ) {
+ global $wgOut, $wgContLang;
+
+ if ($par)
+ $this->setNamespace( $wgContLang->getNsIndex( $par ) );
+
+ $title = $this->getRandomTitle();
+
+ if( is_null( $title ) ) {
+ $this->setHeaders();
+ $wgOut->addWikiMsg( strtolower( $this->mName ) . '-nopages' );
+ return;
+ }
+
+ $query = $this->isRedirect() ? 'redirect=no' : '';
+ $wgOut->redirect( $title->getFullUrl( $query ) );
}
+
/**
* Choose a random title.
* @return Title object (or null if nothing to choose from)
*/
- public function getRandomTitle ( ) {
+ public function getRandomTitle() {
$randstr = wfRandom();
$row = $this->selectRandomPageFromDB( $randstr );
- if( !$row ) {
- // Try again with a normalized value
- $randstr = wfRandom( $this->getMaxPageRandom() );
- $row = $this->selectRandomPageFromDB( $randstr );
- }
+ /* If we picked a value that was higher than any in
+ * the DB, wrap around and select the page with the
+ * lowest value instead! One might think this would
+ * skew the distribution, but in fact it won't cause
+ * any more bias than what the page_random scheme
+ * causes anyway. Trust me, I'm a mathematician. :)
+ */
+ if( !$row )
+ $row = $this->selectRandomPageFromDB( "0" );
if( $row )
return Title::makeTitleSafe( $this->namespace, $row->page_title );
return null;
}
- private function selectRandomPageFromDB ( $randstr ) {
+ private function selectRandomPageFromDB( $randstr ) {
global $wgExtraRandompageSQL;
$fname = 'RandomPage::selectRandomPageFromDB';
$dbr = wfGetDB( DB_SLAVE );
- $from = $this->getSQLFrom( $dbr );
- $where = $this->getSQLWhere( $dbr );
+ $use_index = $dbr->useIndexClause( 'page_random' );
+ $page = $dbr->tableName( 'page' );
- $sql = "SELECT page_title FROM $from
- WHERE $where AND page_random > $randstr
+ $ns = (int) $this->namespace;
+ $redirect = $this->isRedirect() ? 1 : 0;
+
+ $extra = $wgExtraRandompageSQL ? "AND ($wgExtraRandompageSQL)" : "";
+ $sql = "SELECT page_title
+ FROM $page $use_index
+ WHERE page_namespace = $ns
+ AND page_is_redirect = $redirect
+ AND page_random >= $randstr
+ $extra
ORDER BY page_random";
$sql = $dbr->limitResult( $sql, 1, 0 );
$res = $dbr->query( $sql, $fname );
return $dbr->fetchObject( $res );
}
-
- private function getMaxPageRandom () {
- $fname = 'RandomPage::getMaxPageRandom';
-
- $dbr = wfGetDB( DB_SLAVE );
-
- $from = $this->getSQLFrom( $dbr );
- $where = $this->getSQLWhere( $dbr );
-
- $sql = "SELECT MAX(page_random) AS max FROM $from WHERE $where";
-
- $sql = $dbr->limitResult( $sql, 1, 0 );
- $res = $dbr->query( $sql, $fname );
- $row = $dbr->fetchObject( $res );
-
- return $row ? $row->max : 0;
- }
-
- private function getSQLFrom ( $dbr ) {
- $use_index = $dbr->useIndexClause( 'page_random' );
- $page = $dbr->tableName( 'page' );
- return "$page $use_index";
- }
-
- private function getSQLWhere ( $dbr ) {
- global $wgExtraRandompageSQL;
- $ns = (int) $this->namespace;
- $redirect = $this->redirect ? 1 : 0;
- $extra = $wgExtraRandompageSQL ? " AND ($wgExtraRandompageSQL)" : "";
- return "page_namespace = $ns AND page_is_redirect = $redirect" . $extra;
- }
}
-
-?>