includes/installer/DatabaseInstaller.php

   1 <?php
   2 /**
   3  * DBMS-specific installation helper.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Deployment
  22  */
  23 use Wikimedia\Rdbms\LBFactorySingle;
  24 use Wikimedia\Rdbms\Database;
  25 use Wikimedia\Rdbms\IDatabase;
  26
  27 /**
  28  * Base class for DBMS-specific installation helper classes.
  29  *
  30  * @ingroup Deployment
  31  * @since 1.17
  32  */
  33 abstract class DatabaseInstaller {
  34
  35         /**
  36          * The Installer object.
  37          *
  38          * @todo Naming this parent is confusing, 'installer' would be clearer.
  39          *
  40          * @var WebInstaller
  41          */
  42         public $parent;
  43
  44         /**
  45          * @var string Set by subclasses
  46          */
  47         public static $minimumVersion;
  48
  49         /**
  50          * @var string Set by subclasses
  51          */
  52         protected static $notMiniumumVerisonMessage;
  53
  54         /**
  55          * The database connection.
  56          *
  57          * @var Database
  58          */
  59         public $db = null;
  60
  61         /**
  62          * Internal variables for installation.
  63          *
  64          * @var array
  65          */
  66         protected $internalDefaults = [];
  67
  68         /**
  69          * Array of MW configuration globals this class uses.
  70          *
  71          * @var array
  72          */
  73         protected $globalNames = [];
  74
  75         /**
  76          * Whether the provided version meets the necessary requirements for this type
  77          *
  78          * @param string $serverVersion Output of Database::getServerVersion()
  79          * @return Status
  80          * @since 1.30
  81          */
  82         public static function meetsMinimumRequirement( $serverVersion ) {
  83                 if ( version_compare( $serverVersion, static::$minimumVersion ) < 0 ) {
  84                         return Status::newFatal(
  85                                 static::$notMiniumumVerisonMessage, static::$minimumVersion, $serverVersion
  86                         );
  87                 }
  88
  89                 return Status::newGood();
  90         }
  91
  92         /**
  93          * Return the internal name, e.g. 'mysql', or 'sqlite'.
  94          */
  95         abstract public function getName();
  96
  97         /**
  98          * @return bool Returns true if the client library is compiled in.
  99          */
 100         abstract public function isCompiled();
 101
 102         /**
 103          * Checks for installation prerequisites other than those checked by isCompiled()
 104          * @since 1.19
 105          * @return Status
 106          */
 107         public function checkPrerequisites() {
 108                 return Status::newGood();
 109         }
 110
 111         /**
 112          * Get HTML for a web form that configures this database. Configuration
 113          * at this time should be the minimum needed to connect and test
 114          * whether install or upgrade is required.
 115          *
 116          * If this is called, $this->parent can be assumed to be a WebInstaller.
 117          */
 118         abstract public function getConnectForm();
 119
 120         /**
 121          * Set variables based on the request array, assuming it was submitted
 122          * via the form returned by getConnectForm(). Validate the connection
 123          * settings by attempting to connect with them.
 124          *
 125          * If this is called, $this->parent can be assumed to be a WebInstaller.
 126          *
 127          * @return Status
 128          */
 129         abstract public function submitConnectForm();
 130
 131         /**
 132          * Get HTML for a web form that retrieves settings used for installation.
 133          * $this->parent can be assumed to be a WebInstaller.
 134          * If the DB type has no settings beyond those already configured with
 135          * getConnectForm(), this should return false.
 136          * @return bool
 137          */
 138         public function getSettingsForm() {
 139                 return false;
 140         }
 141
 142         /**
 143          * Set variables based on the request array, assuming it was submitted via
 144          * the form return by getSettingsForm().
 145          *
 146          * @return Status
 147          */
 148         public function submitSettingsForm() {
 149                 return Status::newGood();
 150         }
 151
 152         /**
 153          * Open a connection to the database using the administrative user/password
 154          * currently defined in the session, without any caching. Returns a status
 155          * object. On success, the status object will contain a Database object in
 156          * its value member.
 157          *
 158          * @return Status
 159          */
 160         abstract public function openConnection();
 161
 162         /**
 163          * Create the database and return a Status object indicating success or
 164          * failure.
 165          *
 166          * @return Status
 167          */
 168         abstract public function setupDatabase();
 169
 170         /**
 171          * Connect to the database using the administrative user/password currently
 172          * defined in the session. Returns a status object. On success, the status
 173          * object will contain a Database object in its value member.
 174          *
 175          * This will return a cached connection if one is available.
 176          *
 177          * @return Status
 178          */
 179         public function getConnection() {
 180                 if ( $this->db ) {
 181                         return Status::newGood( $this->db );
 182                 }
 183
 184                 $status = $this->openConnection();
 185                 if ( $status->isOK() ) {
 186                         $this->db = $status->value;
 187                         // Enable autocommit
 188                         $this->db->clearFlag( DBO_TRX );
 189                         $this->db->commit( __METHOD__ );
 190                 }
 191
 192                 return $status;
 193         }
 194
 195         /**
 196          * Apply a SQL source file to the database as part of running an installation step.
 197          *
 198          * @param string $sourceFileMethod
 199          * @param string $stepName
 200          * @param bool $archiveTableMustNotExist
 201          * @return Status
 202          */
 203         private function stepApplySourceFile(
 204                 $sourceFileMethod,
 205                 $stepName,
 206                 $archiveTableMustNotExist = false
 207         ) {
 208                 $status = $this->getConnection();
 209                 if ( !$status->isOK() ) {
 210                         return $status;
 211                 }
 212                 $this->db->selectDB( $this->getVar( 'wgDBname' ) );
 213
 214                 if ( $archiveTableMustNotExist && $this->db->tableExists( 'archive', __METHOD__ ) ) {
 215                         $status->warning( "config-$stepName-tables-exist" );
 216                         $this->enableLB();
 217
 218                         return $status;
 219                 }
 220
 221                 $this->db->setFlag( DBO_DDLMODE ); // For Oracle's handling of schema files
 222                 $this->db->begin( __METHOD__ );
 223
 224                 $error = $this->db->sourceFile(
 225                         call_user_func( [ $this, $sourceFileMethod ], $this->db )
 226                 );
 227                 if ( $error !== true ) {
 228                         $this->db->reportQueryError( $error, 0, '', __METHOD__ );
 229                         $this->db->rollback( __METHOD__ );
 230                         $status->fatal( "config-$stepName-tables-failed", $error );
 231                 } else {
 232                         $this->db->commit( __METHOD__ );
 233                 }
 234                 // Resume normal operations
 235                 if ( $status->isOK() ) {
 236                         $this->enableLB();
 237                 }
 238
 239                 return $status;
 240         }
 241
 242         /**
 243          * Create database tables from scratch.
 244          *
 245          * @return Status
 246          */
 247         public function createTables() {
 248                 return $this->stepApplySourceFile( 'getSchemaPath', 'install', true );
 249         }
 250
 251         /**
 252          * Insert update keys into table to prevent running unneded updates.
 253          *
 254          * @return Status
 255          */
 256         public function insertUpdateKeys() {
 257                 return $this->stepApplySourceFile( 'getUpdateKeysPath', 'updates', false );
 258         }
 259
 260         /**
 261          * Return a path to the DBMS-specific SQL file if it exists,
 262          * otherwise default SQL file
 263          *
 264          * @param IDatabase $db
 265          * @param string $filename
 266          * @return string
 267          */
 268         private function getSqlFilePath( $db, $filename ) {
 269                 global $IP;
 270
 271                 $dbmsSpecificFilePath = "$IP/maintenance/" . $db->getType() . "/$filename";
 272                 if ( file_exists( $dbmsSpecificFilePath ) ) {
 273                         return $dbmsSpecificFilePath;
 274                 } else {
 275                         return "$IP/maintenance/$filename";
 276                 }
 277         }
 278
 279         /**
 280          * Return a path to the DBMS-specific schema file,
 281          * otherwise default to tables.sql
 282          *
 283          * @param IDatabase $db
 284          * @return string
 285          */
 286         public function getSchemaPath( $db ) {
 287                 return $this->getSqlFilePath( $db, 'tables.sql' );
 288         }
 289
 290         /**
 291          * Return a path to the DBMS-specific update key file,
 292          * otherwise default to update-keys.sql
 293          *
 294          * @param IDatabase $db
 295          * @return string
 296          */
 297         public function getUpdateKeysPath( $db ) {
 298                 return $this->getSqlFilePath( $db, 'update-keys.sql' );
 299         }
 300
 301         /**
 302          * Create the tables for each extension the user enabled
 303          * @return Status
 304          */
 305         public function createExtensionTables() {
 306                 $status = $this->getConnection();
 307                 if ( !$status->isOK() ) {
 308                         return $status;
 309                 }
 310
 311                 // Now run updates to create tables for old extensions
 312                 DatabaseUpdater::newForDB( $this->db )->doUpdates( [ 'extensions' ] );
 313
 314                 return $status;
 315         }
 316
 317         /**
 318          * Get the DBMS-specific options for LocalSettings.php generation.
 319          *
 320          * @return string
 321          */
 322         abstract public function getLocalSettings();
 323
 324         /**
 325          * Override this to provide DBMS-specific schema variables, to be
 326          * substituted into tables.sql and other schema files.
 327          * @return array
 328          */
 329         public function getSchemaVars() {
 330                 return [];
 331         }
 332
 333         /**
 334          * Set appropriate schema variables in the current database connection.
 335          *
 336          * This should be called after any request data has been imported, but before
 337          * any write operations to the database.
 338          */
 339         public function setupSchemaVars() {
 340                 $status = $this->getConnection();
 341                 if ( $status->isOK() ) {
 342                         $status->value->setSchemaVars( $this->getSchemaVars() );
 343                 } else {
 344                         $msg = __METHOD__ . ': unexpected error while establishing'
 345                                 . ' a database connection with message: '
 346                                 . $status->getMessage()->plain();
 347                         throw new MWException( $msg );
 348                 }
 349         }
 350
 351         /**
 352          * Set up LBFactory so that wfGetDB() etc. works.
 353          * We set up a special LBFactory instance which returns the current
 354          * installer connection.
 355          */
 356         public function enableLB() {
 357                 $status = $this->getConnection();
 358                 if ( !$status->isOK() ) {
 359                         throw new MWException( __METHOD__ . ': unexpected DB connection error' );
 360                 }
 361
 362                 \MediaWiki\MediaWikiServices::resetGlobalInstance();
 363                 $services = \MediaWiki\MediaWikiServices::getInstance();
 364
 365                 $connection = $status->value;
 366                 $services->redefineService( 'DBLoadBalancerFactory', function () use ( $connection ) {
 367                         return LBFactorySingle::newFromConnection( $connection );
 368                 } );
 369         }
 370
 371         /**
 372          * Perform database upgrades
 373          *
 374          * @return bool
 375          */
 376         public function doUpgrade() {
 377                 $this->setupSchemaVars();
 378                 $this->enableLB();
 379
 380                 $ret = true;
 381                 ob_start( [ $this, 'outputHandler' ] );
 382                 $up = DatabaseUpdater::newForDB( $this->db );
 383                 try {
 384                         $up->doUpdates();
 385                 } catch ( MWException $e ) {
 386                         echo "\nAn error occurred:\n";
 387                         echo $e->getText();
 388                         $ret = false;
 389                 } catch ( Exception $e ) {
 390                         echo "\nAn error occurred:\n";
 391                         echo $e->getMessage();
 392                         $ret = false;
 393                 }
 394                 $up->purgeCache();
 395                 ob_end_flush();
 396
 397                 return $ret;
 398         }
 399
 400         /**
 401          * Allow DB installers a chance to make last-minute changes before installation
 402          * occurs. This happens before setupDatabase() or createTables() is called, but
 403          * long after the constructor. Helpful for things like modifying setup steps :)
 404          */
 405         public function preInstall() {
 406         }
 407
 408         /**
 409          * Allow DB installers a chance to make checks before upgrade.
 410          */
 411         public function preUpgrade() {
 412         }
 413
 414         /**
 415          * Get an array of MW configuration globals that will be configured by this class.
 416          * @return array
 417          */
 418         public function getGlobalNames() {
 419                 return $this->globalNames;
 420         }
 421
 422         /**
 423          * Construct and initialise parent.
 424          * This is typically only called from Installer::getDBInstaller()
 425          * @param WebInstaller $parent
 426          */
 427         public function __construct( $parent ) {
 428                 $this->parent = $parent;
 429         }
 430
 431         /**
 432          * Convenience function.
 433          * Check if a named extension is present.
 434          *
 435          * @param string $name
 436          * @return bool
 437          */
 438         protected static function checkExtension( $name ) {
 439                 return extension_loaded( $name );
 440         }
 441
 442         /**
 443          * Get the internationalised name for this DBMS.
 444          * @return string
 445          */
 446         public function getReadableName() {
 447                 // Messages: config-type-mysql, config-type-postgres, config-type-sqlite,
 448                 // config-type-oracle
 449                 return wfMessage( 'config-type-' . $this->getName() )->text();
 450         }
 451
 452         /**
 453          * Get a name=>value map of MW configuration globals for the default values.
 454          * @return array
 455          */
 456         public function getGlobalDefaults() {
 457                 $defaults = [];
 458                 foreach ( $this->getGlobalNames() as $var ) {
 459                         if ( isset( $GLOBALS[$var] ) ) {
 460                                 $defaults[$var] = $GLOBALS[$var];
 461                         }
 462                 }
 463                 return $defaults;
 464         }
 465
 466         /**
 467          * Get a name=>value map of internal variables used during installation.
 468          * @return array
 469          */
 470         public function getInternalDefaults() {
 471                 return $this->internalDefaults;
 472         }
 473
 474         /**
 475          * Get a variable, taking local defaults into account.
 476          * @param string $var
 477          * @param mixed|null $default
 478          * @return mixed
 479          */
 480         public function getVar( $var, $default = null ) {
 481                 $defaults = $this->getGlobalDefaults();
 482                 $internal = $this->getInternalDefaults();
 483                 if ( isset( $defaults[$var] ) ) {
 484                         $default = $defaults[$var];
 485                 } elseif ( isset( $internal[$var] ) ) {
 486                         $default = $internal[$var];
 487                 }
 488
 489                 return $this->parent->getVar( $var, $default );
 490         }
 491
 492         /**
 493          * Convenience alias for $this->parent->setVar()
 494          * @param string $name
 495          * @param mixed $value
 496          */
 497         public function setVar( $name, $value ) {
 498                 $this->parent->setVar( $name, $value );
 499         }
 500
 501         /**
 502          * Get a labelled text box to configure a local variable.
 503          *
 504          * @param string $var
 505          * @param string $label
 506          * @param array $attribs
 507          * @param string $helpData
 508          * @return string
 509          */
 510         public function getTextBox( $var, $label, $attribs = [], $helpData = "" ) {
 511                 $name = $this->getName() . '_' . $var;
 512                 $value = $this->getVar( $var );
 513                 if ( !isset( $attribs ) ) {
 514                         $attribs = [];
 515                 }
 516
 517                 return $this->parent->getTextBox( [
 518                         'var' => $var,
 519                         'label' => $label,
 520                         'attribs' => $attribs,
 521                         'controlName' => $name,
 522                         'value' => $value,
 523                         'help' => $helpData
 524                 ] );
 525         }
 526
 527         /**
 528          * Get a labelled password box to configure a local variable.
 529          * Implements password hiding.
 530          *
 531          * @param string $var
 532          * @param string $label
 533          * @param array $attribs
 534          * @param string $helpData
 535          * @return string
 536          */
 537         public function getPasswordBox( $var, $label, $attribs = [], $helpData = "" ) {
 538                 $name = $this->getName() . '_' . $var;
 539                 $value = $this->getVar( $var );
 540                 if ( !isset( $attribs ) ) {
 541                         $attribs = [];
 542                 }
 543
 544                 return $this->parent->getPasswordBox( [
 545                         'var' => $var,
 546                         'label' => $label,
 547                         'attribs' => $attribs,
 548                         'controlName' => $name,
 549                         'value' => $value,
 550                         'help' => $helpData
 551                 ] );
 552         }
 553
 554         /**
 555          * Get a labelled checkbox to configure a local boolean variable.
 556          *
 557          * @param string $var
 558          * @param string $label
 559          * @param array $attribs Optional.
 560          * @param string $helpData Optional.
 561          * @return string
 562          */
 563         public function getCheckBox( $var, $label, $attribs = [], $helpData = "" ) {
 564                 $name = $this->getName() . '_' . $var;
 565                 $value = $this->getVar( $var );
 566
 567                 return $this->parent->getCheckBox( [
 568                         'var' => $var,
 569                         'label' => $label,
 570                         'attribs' => $attribs,
 571                         'controlName' => $name,
 572                         'value' => $value,
 573                         'help' => $helpData
 574                 ] );
 575         }
 576
 577         /**
 578          * Get a set of labelled radio buttons.
 579          *
 580          * @param array $params Parameters are:
 581          *      var:            The variable to be configured (required)
 582          *      label:          The message name for the label (required)
 583          *      itemLabelPrefix: The message name prefix for the item labels (required)
 584          *      values:         List of allowed values (required)
 585          *      itemAttribs     Array of attribute arrays, outer key is the value name (optional)
 586          *
 587          * @return string
 588          */
 589         public function getRadioSet( $params ) {
 590                 $params['controlName'] = $this->getName() . '_' . $params['var'];
 591                 $params['value'] = $this->getVar( $params['var'] );
 592
 593                 return $this->parent->getRadioSet( $params );
 594         }
 595
 596         /**
 597          * Convenience function to set variables based on form data.
 598          * Assumes that variables containing "password" in the name are (potentially
 599          * fake) passwords.
 600          * @param array $varNames
 601          * @return array
 602          */
 603         public function setVarsFromRequest( $varNames ) {
 604                 return $this->parent->setVarsFromRequest( $varNames, $this->getName() . '_' );
 605         }
 606
 607         /**
 608          * Determine whether an existing installation of MediaWiki is present in
 609          * the configured administrative connection. Returns true if there is
 610          * such a wiki, false if the database doesn't exist.
 611          *
 612          * Traditionally, this is done by testing for the existence of either
 613          * the revision table or the cur table.
 614          *
 615          * @return bool
 616          */
 617         public function needsUpgrade() {
 618                 $status = $this->getConnection();
 619                 if ( !$status->isOK() ) {
 620                         return false;
 621                 }
 622
 623                 if ( !$this->db->selectDB( $this->getVar( 'wgDBname' ) ) ) {
 624                         return false;
 625                 }
 626
 627                 return $this->db->tableExists( 'cur', __METHOD__ ) ||
 628                         $this->db->tableExists( 'revision', __METHOD__ );
 629         }
 630
 631         /**
 632          * Get a standard install-user fieldset.
 633          *
 634          * @return string
 635          */
 636         public function getInstallUserBox() {
 637                 return Html::openElement( 'fieldset' ) .
 638                         Html::element( 'legend', [], wfMessage( 'config-db-install-account' )->text() ) .
 639                         $this->getTextBox(
 640                                 '_InstallUser',
 641                                 'config-db-username',
 642                                 [ 'dir' => 'ltr' ],
 643                                 $this->parent->getHelpBox( 'config-db-install-username' )
 644                         ) .
 645                         $this->getPasswordBox(
 646                                 '_InstallPassword',
 647                                 'config-db-password',
 648                                 [ 'dir' => 'ltr' ],
 649                                 $this->parent->getHelpBox( 'config-db-install-password' )
 650                         ) .
 651                         Html::closeElement( 'fieldset' );
 652         }
 653
 654         /**
 655          * Submit a standard install user fieldset.
 656          * @return Status
 657          */
 658         public function submitInstallUserBox() {
 659                 $this->setVarsFromRequest( [ '_InstallUser', '_InstallPassword' ] );
 660
 661                 return Status::newGood();
 662         }
 663
 664         /**
 665          * Get a standard web-user fieldset
 666          * @param string|bool $noCreateMsg Message to display instead of the creation checkbox.
 667          *   Set this to false to show a creation checkbox (default).
 668          *
 669          * @return string
 670          */
 671         public function getWebUserBox( $noCreateMsg = false ) {
 672                 $wrapperStyle = $this->getVar( '_SameAccount' ) ? 'display: none' : '';
 673                 $s = Html::openElement( 'fieldset' ) .
 674                         Html::element( 'legend', [], wfMessage( 'config-db-web-account' )->text() ) .
 675                         $this->getCheckBox(
 676                                 '_SameAccount', 'config-db-web-account-same',
 677                                 [ 'class' => 'hideShowRadio', 'rel' => 'dbOtherAccount' ]
 678                         ) .
 679                         Html::openElement( 'div', [ 'id' => 'dbOtherAccount', 'style' => $wrapperStyle ] ) .
 680                         $this->getTextBox( 'wgDBuser', 'config-db-username' ) .
 681                         $this->getPasswordBox( 'wgDBpassword', 'config-db-password' ) .
 682                         $this->parent->getHelpBox( 'config-db-web-help' );
 683                 if ( $noCreateMsg ) {
 684                         $s .= $this->parent->getWarningBox( wfMessage( $noCreateMsg )->plain() );
 685                 } else {
 686                         $s .= $this->getCheckBox( '_CreateDBAccount', 'config-db-web-create' );
 687                 }
 688                 $s .= Html::closeElement( 'div' ) . Html::closeElement( 'fieldset' );
 689
 690                 return $s;
 691         }
 692
 693         /**
 694          * Submit the form from getWebUserBox().
 695          *
 696          * @return Status
 697          */
 698         public function submitWebUserBox() {
 699                 $this->setVarsFromRequest(
 700                         [ 'wgDBuser', 'wgDBpassword', '_SameAccount', '_CreateDBAccount' ]
 701                 );
 702
 703                 if ( $this->getVar( '_SameAccount' ) ) {
 704                         $this->setVar( 'wgDBuser', $this->getVar( '_InstallUser' ) );
 705                         $this->setVar( 'wgDBpassword', $this->getVar( '_InstallPassword' ) );
 706                 }
 707
 708                 if ( $this->getVar( '_CreateDBAccount' ) && strval( $this->getVar( 'wgDBpassword' ) ) == '' ) {
 709                         return Status::newFatal( 'config-db-password-empty', $this->getVar( 'wgDBuser' ) );
 710                 }
 711
 712                 return Status::newGood();
 713         }
 714
 715         /**
 716          * Common function for databases that don't understand the MySQLish syntax of interwiki.sql.
 717          *
 718          * @return Status
 719          */
 720         public function populateInterwikiTable() {
 721                 $status = $this->getConnection();
 722                 if ( !$status->isOK() ) {
 723                         return $status;
 724                 }
 725                 $this->db->selectDB( $this->getVar( 'wgDBname' ) );
 726
 727                 if ( $this->db->selectRow( 'interwiki', '1', [], __METHOD__ ) ) {
 728                         $status->warning( 'config-install-interwiki-exists' );
 729
 730                         return $status;
 731                 }
 732                 global $IP;
 733                 MediaWiki\suppressWarnings();
 734                 $rows = file( "$IP/maintenance/interwiki.list",
 735                         FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES );
 736                 MediaWiki\restoreWarnings();
 737                 $interwikis = [];
 738                 if ( !$rows ) {
 739                         return Status::newFatal( 'config-install-interwiki-list' );
 740                 }
 741                 foreach ( $rows as $row ) {
 742                         $row = preg_replace( '/^\s*([^#]*?)\s*(#.*)?$/', '\\1', $row ); // strip comments - whee
 743                         if ( $row == "" ) {
 744                                 continue;
 745                         }
 746                         $row .= "|";
 747                         $interwikis[] = array_combine(
 748                                 [ 'iw_prefix', 'iw_url', 'iw_local', 'iw_api', 'iw_wikiid' ],
 749                                 explode( '|', $row )
 750                         );
 751                 }
 752                 $this->db->insert( 'interwiki', $interwikis, __METHOD__ );
 753
 754                 return Status::newGood();
 755         }
 756
 757         public function outputHandler( $string ) {
 758                 return htmlspecialchars( $string );
 759         }
 760 }