Followup to r79848 (and really, make it useful...)

Turn DatabaseBase::classFromType() into newFromType() factory function for constructing a new object based on a given type and (optional) params. Documented it fairly clearly.

I think it looks nicer :)

includes/db/Database.php

@@ -522,11 +522,7 @@ abstract class DatabaseBase implements DatabaseType {
 
 	/**
 	 * Same as new DatabaseMysql( ... ), kept for backward compatibility
-	 * @param $server String: database server host
-	 * @param $user String: database user name
-	 * @param $password String: database user password
-	 * @param $dbName String: database name
-	 * @param $flags
+	 * @deprecated
 	 */
 	static function newFromParams( $server, $user, $password, $dbName, $flags = 0 ) {
 		wfDeprecated( __METHOD__ );
@@ -539,16 +535,36 @@ abstract class DatabaseBase implements DatabaseType {
 	 *	$class = 'Database' . ucfirst( strtolower( $type ) );
 	 * as well as validate against the canonical list of DB types we have
 	 *
+	 * This factory function is mostly useful for when you need to connect to a
+	 * database other than the MediaWiki default (such as for external auth,
+	 * an extension, et cetera). Do not use this to connect to the MediaWiki
+	 * database. Example uses in core:
+	 * @see LoadBalancer::reallyOpenConnection()
+	 * @see ExternalUser_MediaWiki::initFromCond()
+	 * @see ForeignDBRepo::getMasterDB()
+	 * @see WebInstaller_DBConnect::execute()
+	 *
 	 * @param $dbType String A possible DB type
+	 * @param $p Array An array of options to pass to the constructor.
+	 *    Valid options are: host, user, password, dbname, flags, tableprefix
 	 * @return DatabaseBase subclass or null
 	 */
-	public final static function classFromType( $dbType ) {
+	public final static function newFromType( $dbType, $p = array() ) {
 		$canonicalDBTypes = array(
 			'mysql', 'postgres', 'sqlite', 'oracle', 'mssql', 'ibm_db2'
 		);
 		$dbType = strtolower( $dbType );
+
 		if( in_array( $dbType, $canonicalDBTypes ) ) {
-			return 'Database' . ucfirst( $dbType );
+			$class = 'Database' . ucfirst( $dbType );
+			return new $class(
+				isset( $p['host'] ) ? $p['host'] : false,
+				isset( $p['user'] ) ? $p['user'] : false,
+				isset( $p['password'] ) ? $p['password'] : false,
+				isset( $p['dbname'] ) ? $p['dbname'] : false,
+				isset( $p['flags'] ) ? $p['flags'] : 0,
+				isset( $p['tableprefix'] ) ? $p['tableprefix'] : 'get from global'
+			);
 		} else {
 			return null;
 		}

includes/db/LoadBalancer.php

@@ -620,23 +620,16 @@ class LoadBalancer {
 			                       'See DefaultSettings.php entry for $wgDBservers.' );
 		}
 
-		$type = $server['type'];
 		$host = $server['host'];
-		$user = $server['user'];
-		$password = $server['password'];
-		$flags = $server['flags'];
 		$dbname = $server['dbname'];
 
 		if ( $dbNameOverride !== false ) {
 			$dbname = $dbNameOverride;
 		}
 
-		# Get class for this database type
-		$class = DatabaseBase::classFromType( $type );
-
 		# Create object
 		wfDebug( "Connecting to $host $dbname...\n" );
-		$db = new $class( $host, $user, $password, $dbname, $flags );
+		$db = DatabaseBase::newFromType( $server['type'], $server );
 		if ( $db->isOpen() ) {
 			wfDebug( "Connected to $host $dbname.\n" );
 		} else {

includes/extauth/MediaWiki.php

@@ -72,14 +72,14 @@ class ExternalUser_MediaWiki extends ExternalUser {
 	private function initFromCond( $cond ) {
 		global $wgExternalAuthConf;
 
-		$class = DatabaseBase::classFromType( $wgExternalAuthConf['DBtype'] );
-		$this->mDb = new $class(
-			$wgExternalAuthConf['DBserver'],
-			$wgExternalAuthConf['DBuser'],
-			$wgExternalAuthConf['DBpassword'],
-			$wgExternalAuthConf['DBname'],
-			0,
-			$wgExternalAuthConf['DBprefix']
+		$this->mDb = DatabaseBase::newFromType( $wgExternalAuthConf['DBtype'],
+			array(
+				'server'      => $wgExternalAuthConf['DBserver'],
+				'user'        => $wgExternalAuthConf['DBuser'],
+				'password'    => $wgExternalAuthConf['DBpassword'],
+				'dbname'      => $wgExternalAuthConf['DBname'],
+				'tableprefix' => $wgExternalAuthConf['DBprefix'],
+			)
 		);
 
 		$row = $this->mDb->selectRow(

includes/filerepo/ForeignDBRepo.php

@@ -35,10 +35,16 @@ class ForeignDBRepo extends LocalRepo {
 
 	function getMasterDB() {
 		if ( !isset( $this->dbConn ) ) {
-			$class = DatabaseBase::classFromType( $this->dbType );
-			$this->dbConn = new $class( $this->dbServer, $this->dbUser,
-				$this->dbPassword, $this->dbName, $this->dbFlags,
-				$this->tablePrefix );
+			$this->dbConn = DatabaseBase::newFromType( $this->dbType,
+				array(
+					'server' => $this->dbServer,
+					'user'   => $this->dbUser,
+					'password' => $this->dbPassword,
+					'dbname' => $this->dbName,
+					'flags' => $this->dbFlags,
+					'tableprefix' => $this->tablePrefix
+				)
+			);
 		}
 		return $this->dbConn;
 	}

includes/installer/WebInstallerPage.php

@@ -384,9 +384,8 @@ class WebInstaller_DBConnect extends WebInstallerPage {
 
 		$dbSupport = '';
 		foreach( $this->parent->getDBTypes() as $type ) {
-			$db = DatabaseBase::classFromType( $type );
-			$dbSupport .= wfMsgNoTrans( "config-support-$type",
-				call_user_func( array( $db, 'getSoftwareLink' ) ) ) . "\n";
+			$link = DatabaseBase::newFromType( $type )->getSoftwareLink();
+			$dbSupport .= wfMsgNoTrans( "config-support-$type", $link ) . "\n";
 		}
 		$this->addHTML( $this->parent->getInfoBox(
 			wfMsg( 'config-support-info', $dbSupport ) ) );