includes/Xml.php

   1 <?php
   2 /**
   3  * Methods to generate XML.
   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  */
  22
  23 /**
  24  * Module of static functions for generating XML
  25  */
  26 class Xml {
  27         /**
  28          * Format an XML element with given attributes and, optionally, text content.
  29          * Element and attribute names are assumed to be ready for literal inclusion.
  30          * Strings are assumed to not contain XML-illegal characters; special
  31          * characters (<, >, &) are escaped but illegals are not touched.
  32          *
  33          * @param string $element Element name
  34          * @param array $attribs Name=>value pairs. Values will be escaped.
  35          * @param string $contents Null to make an open tag only; '' for a contentless closed tag (default)
  36          * @param bool $allowShortTag Whether '' in $contents will result in a contentless closed tag
  37          * @return string
  38          */
  39         public static function element( $element, $attribs = null, $contents = '',
  40                 $allowShortTag = true
  41         ) {
  42                 $out = '<' . $element;
  43                 if ( !is_null( $attribs ) ) {
  44                         $out .= self::expandAttributes( $attribs );
  45                 }
  46                 if ( is_null( $contents ) ) {
  47                         $out .= '>';
  48                 } else {
  49                         if ( $allowShortTag && $contents === '' ) {
  50                                 $out .= ' />';
  51                         } else {
  52                                 $out .= '>' . htmlspecialchars( $contents ) . "</$element>";
  53                         }
  54                 }
  55                 return $out;
  56         }
  57
  58         /**
  59          * Given an array of ('attributename' => 'value'), it generates the code
  60          * to set the XML attributes : attributename="value".
  61          * The values are passed to Sanitizer::encodeAttribute.
  62          * Return null if no attributes given.
  63          * @param array $attribs Array of attributes for an XML element
  64          * @throws MWException
  65          * @return null|string
  66          */
  67         public static function expandAttributes( $attribs ) {
  68                 $out = '';
  69                 if ( is_null( $attribs ) ) {
  70                         return null;
  71                 } elseif ( is_array( $attribs ) ) {
  72                         foreach ( $attribs as $name => $val ) {
  73                                 $out .= " {$name}=\"" . Sanitizer::encodeAttribute( $val ) . '"';
  74                         }
  75                         return $out;
  76                 } else {
  77                         throw new MWException( 'Expected attribute array, got something else in ' . __METHOD__ );
  78                 }
  79         }
  80
  81         /**
  82          * Format an XML element as with self::element(), but run text through the
  83          * $wgContLang->normalize() validator first to ensure that no invalid UTF-8
  84          * is passed.
  85          *
  86          * @param string $element
  87          * @param array $attribs Name=>value pairs. Values will be escaped.
  88          * @param string $contents Null to make an open tag only; '' for a contentless closed tag (default)
  89          * @return string
  90          */
  91         public static function elementClean( $element, $attribs = array(), $contents = '' ) {
  92                 global $wgContLang;
  93                 if ( $attribs ) {
  94                         $attribs = array_map( array( 'UtfNormal', 'cleanUp' ), $attribs );
  95                 }
  96                 if ( $contents ) {
  97                         $contents = $wgContLang->normalize( $contents );
  98                 }
  99                 return self::element( $element, $attribs, $contents );
 100         }
 101
 102         /**
 103          * This opens an XML element
 104          *
 105          * @param string $element Name of the element
 106          * @param array $attribs Array of attributes, see Xml::expandAttributes()
 107          * @return string
 108          */
 109         public static function openElement( $element, $attribs = null ) {
 110                 return '<' . $element . self::expandAttributes( $attribs ) . '>';
 111         }
 112
 113         /**
 114          * Shortcut to close an XML element
 115          * @param string $element Element name
 116          * @return string
 117          */
 118         public static function closeElement( $element ) {
 119                 return "</$element>";
 120         }
 121
 122         /**
 123          * Same as Xml::element(), but does not escape contents. Handy when the
 124          * content you have is already valid xml.
 125          *
 126          * @param string $element Element name
 127          * @param array $attribs Array of attributes
 128          * @param string $contents Content of the element
 129          * @return string
 130          */
 131         public static function tags( $element, $attribs = null, $contents ) {
 132                 return self::openElement( $element, $attribs ) . $contents . "</$element>";
 133         }
 134
 135         /**
 136          * Create a date selector
 137          *
 138          * @param string $selected The month which should be selected, default ''.
 139          * @param string $allmonths Value of a special item denoting all month.
 140          *   Null to not include (default).
 141          * @param string $id Element identifier
 142          * @return string Html string containing the month selector
 143          */
 144         public static function monthSelector( $selected = '', $allmonths = null, $id = 'month' ) {
 145                 global $wgLang;
 146                 $options = array();
 147                 if ( is_null( $selected ) ) {
 148                         $selected = '';
 149                 }
 150                 if ( !is_null( $allmonths ) ) {
 151                         $options[] = self::option(
 152                                 wfMessage( 'monthsall' )->text(),
 153                                 $allmonths,
 154                                 $selected === $allmonths
 155                         );
 156                 }
 157                 for ( $i = 1; $i < 13; $i++ ) {
 158                         $options[] = self::option( $wgLang->getMonthName( $i ), $i, $selected === $i );
 159                 }
 160                 return self::openElement( 'select', array(
 161                         'id' => $id,
 162                         'name' => 'month',
 163                         'class' => 'mw-month-selector'
 164                 ) )
 165                         . implode( "\n", $options )
 166                         . self::closeElement( 'select' );
 167         }
 168
 169         /**
 170          * @param int $year
 171          * @param int $month
 172          * @return string Formatted HTML
 173          */
 174         public static function dateMenu( $year, $month ) {
 175                 # Offset overrides year/month selection
 176                 if ( $month && $month !== -1 ) {
 177                         $encMonth = intval( $month );
 178                 } else {
 179                         $encMonth = '';
 180                 }
 181                 if ( $year ) {
 182                         $encYear = intval( $year );
 183                 } elseif ( $encMonth ) {
 184                         $timestamp = MWTimestamp::getInstance();
 185                         $thisMonth = intval( $timestamp->format( 'n' ) );
 186                         $thisYear = intval( $timestamp->format( 'Y' ) );
 187                         if ( intval( $encMonth ) > $thisMonth ) {
 188                                 $thisYear--;
 189                         }
 190                         $encYear = $thisYear;
 191                 } else {
 192                         $encYear = '';
 193                 }
 194                 $inputAttribs = array( 'id' => 'year', 'maxlength' => 4, 'size' => 7 );
 195                 return self::label( wfMessage( 'year' )->text(), 'year' ) . ' ' .
 196                         Html::input( 'year', $encYear, 'number', $inputAttribs ) . ' ' .
 197                         self::label( wfMessage( 'month' )->text(), 'month' ) . ' ' .
 198                         self::monthSelector( $encMonth, -1 );
 199         }
 200
 201         /**
 202          * Construct a language selector appropriate for use in a form or preferences
 203          *
 204          * @param string $selected The language code of the selected language
 205          * @param bool $customisedOnly If true only languages which have some content are listed
 206          * @param string $inLanguage The ISO code of the language to display the select list in (optional)
 207          * @param array $overrideAttrs Override the attributes of the select tag (since 1.20)
 208          * @param Message|null $msg Label message key (since 1.20)
 209          * @return array Array containing 2 items: label HTML and select list HTML
 210          */
 211         public static function languageSelector( $selected, $customisedOnly = true,
 212                 $inLanguage = null, $overrideAttrs = array(), Message $msg = null
 213         ) {
 214                 global $wgLanguageCode;
 215
 216                 $include = $customisedOnly ? 'mwfile' : 'mw';
 217                 $languages = Language::fetchLanguageNames( $inLanguage, $include );
 218
 219                 // Make sure the site language is in the list;
 220                 // a custom language code might not have a defined name...
 221                 if ( !array_key_exists( $wgLanguageCode, $languages ) ) {
 222                         $languages[$wgLanguageCode] = $wgLanguageCode;
 223                 }
 224
 225                 ksort( $languages );
 226
 227                 /**
 228                  * If a bogus value is set, default to the content language.
 229                  * Otherwise, no default is selected and the user ends up
 230                  * with Afrikaans since it's first in the list.
 231                  */
 232                 $selected = isset( $languages[$selected] ) ? $selected : $wgLanguageCode;
 233                 $options = "\n";
 234                 foreach ( $languages as $code => $name ) {
 235                         $options .= Xml::option( "$code - $name", $code, $code == $selected ) . "\n";
 236                 }
 237
 238                 $attrs = array( 'id' => 'wpUserLanguage', 'name' => 'wpUserLanguage' );
 239                 $attrs = array_merge( $attrs, $overrideAttrs );
 240
 241                 if ( $msg === null ) {
 242                         $msg = wfMessage( 'yourlanguage' );
 243                 }
 244                 return array(
 245                         Xml::label( $msg->text(), $attrs['id'] ),
 246                         Xml::tags( 'select', $attrs, $options )
 247                 );
 248
 249         }
 250
 251         /**
 252          * Shortcut to make a span element
 253          * @param string $text Content of the element, will be escaped
 254          * @param string $class Class name of the span element
 255          * @param array $attribs Other attributes
 256          * @return string
 257          */
 258         public static function span( $text, $class, $attribs = array() ) {
 259                 return self::element( 'span', array( 'class' => $class ) + $attribs, $text );
 260         }
 261
 262         /**
 263          * Shortcut to make a specific element with a class attribute
 264          * @param string $text Content of the element, will be escaped
 265          * @param string $class Class name of the span element
 266          * @param string $tag Element name
 267          * @param array $attribs Other attributes
 268          * @return string
 269          */
 270         public static function wrapClass( $text, $class, $tag = 'span', $attribs = array() ) {
 271                 return self::tags( $tag, array( 'class' => $class ) + $attribs, $text );
 272         }
 273
 274         /**
 275          * Convenience function to build an HTML text input field
 276          * @param string $name Value of the name attribute
 277          * @param int $size Value of the size attribute
 278          * @param mixed $value Value of the value attribute
 279          * @param array $attribs Other attributes
 280          * @return string HTML
 281          */
 282         public static function input( $name, $size = false, $value = false, $attribs = array() ) {
 283                 $attributes = array( 'name' => $name );
 284
 285                 if ( $size ) {
 286                         $attributes['size'] = $size;
 287                 }
 288
 289                 if ( $value !== false ) { // maybe 0
 290                         $attributes['value'] = $value;
 291                 }
 292
 293                 return self::element( 'input',
 294                         Html::getTextInputAttributes( $attributes + $attribs ) );
 295         }
 296
 297         /**
 298          * Convenience function to build an HTML password input field
 299          * @param string $name Value of the name attribute
 300          * @param int $size Value of the size attribute
 301          * @param mixed $value Value of the value attribute
 302          * @param array $attribs Other attributes
 303          * @return string HTML
 304          */
 305         public static function password( $name, $size = false, $value = false,
 306                 $attribs = array()
 307         ) {
 308                 return self::input( $name, $size, $value,
 309                         array_merge( $attribs, array( 'type' => 'password' ) ) );
 310         }
 311
 312         /**
 313          * Internal function for use in checkboxes and radio buttons and such.
 314          *
 315          * @param string $name
 316          * @param bool $present
 317          *
 318          * @return array
 319          */
 320         public static function attrib( $name, $present = true ) {
 321                 return $present ? array( $name => $name ) : array();
 322         }
 323
 324         /**
 325          * Convenience function to build an HTML checkbox
 326          * @param string $name Value of the name attribute
 327          * @param bool $checked Whether the checkbox is checked or not
 328          * @param array $attribs Array other attributes
 329          * @return string HTML
 330          */
 331         public static function check( $name, $checked = false, $attribs = array() ) {
 332                 return self::element( 'input', array_merge(
 333                         array(
 334                                 'name' => $name,
 335                                 'type' => 'checkbox',
 336                                 'value' => 1 ),
 337                         self::attrib( 'checked', $checked ),
 338                         $attribs ) );
 339         }
 340
 341         /**
 342          * Convenience function to build an HTML radio button
 343          * @param string $name Value of the name attribute
 344          * @param string $value Value of the value attribute
 345          * @param bool $checked Whether the checkbox is checked or not
 346          * @param array $attribs Other attributes
 347          * @return string HTML
 348          */
 349         public static function radio( $name, $value, $checked = false, $attribs = array() ) {
 350                 return self::element( 'input', array(
 351                         'name' => $name,
 352                         'type' => 'radio',
 353                         'value' => $value ) + self::attrib( 'checked', $checked ) + $attribs );
 354         }
 355
 356         /**
 357          * Convenience function to build an HTML form label
 358          * @param string $label Text of the label
 359          * @param string $id
 360          * @param array $attribs An attribute array.  This will usually be
 361          *     the same array as is passed to the corresponding input element,
 362          *     so this function will cherry-pick appropriate attributes to
 363          *     apply to the label as well; only class and title are applied.
 364          * @return string HTML
 365          */
 366         public static function label( $label, $id, $attribs = array() ) {
 367                 $a = array( 'for' => $id );
 368
 369                 foreach ( array( 'class', 'title' ) as $attr ) {
 370                         if ( isset( $attribs[$attr] ) ) {
 371                                 $a[$attr] = $attribs[$attr];
 372                         }
 373                 }
 374
 375                 return self::element( 'label', $a, $label );
 376         }
 377
 378         /**
 379          * Convenience function to build an HTML text input field with a label
 380          * @param string $label Text of the label
 381          * @param string $name Value of the name attribute
 382          * @param string $id Id of the input
 383          * @param int|bool $size Value of the size attribute
 384          * @param string|bool $value Value of the value attribute
 385          * @param array $attribs Other attributes
 386          * @return string HTML
 387          */
 388         public static function inputLabel( $label, $name, $id, $size = false,
 389                 $value = false, $attribs = array()
 390         ) {
 391                 list( $label, $input ) = self::inputLabelSep( $label, $name, $id, $size, $value, $attribs );
 392                 return $label . '&#160;' . $input;
 393         }
 394
 395         /**
 396          * Same as Xml::inputLabel() but return input and label in an array
 397          *
 398          * @param string $label
 399          * @param string $name
 400          * @param string $id
 401          * @param int|bool $size
 402          * @param string|bool $value
 403          * @param array $attribs
 404          *
 405          * @return array
 406          */
 407         public static function inputLabelSep( $label, $name, $id, $size = false,
 408                 $value = false, $attribs = array()
 409         ) {
 410                 return array(
 411                         Xml::label( $label, $id, $attribs ),
 412                         self::input( $name, $size, $value, array( 'id' => $id ) + $attribs )
 413                 );
 414         }
 415
 416         /**
 417          * Convenience function to build an HTML checkbox with a label
 418          *
 419          * @param string $label
 420          * @param string $name
 421          * @param string $id
 422          * @param bool $checked
 423          * @param array $attribs
 424          *
 425          * @return string HTML
 426          */
 427         public static function checkLabel( $label, $name, $id, $checked = false, $attribs = array() ) {
 428                 global $wgUseMediaWikiUIEverywhere;
 429                 $chkLabel = self::check( $name, $checked, array( 'id' => $id ) + $attribs ) .
 430                         '&#160;' .
 431                         self::label( $label, $id, $attribs );
 432
 433                 if ( $wgUseMediaWikiUIEverywhere ) {
 434                         $chkLabel = self::openElement( 'div', array( 'class' => 'mw-ui-checkbox' ) ) .
 435                                 $chkLabel . self::closeElement( 'div' );
 436                 }
 437                 return $chkLabel;
 438         }
 439
 440         /**
 441          * Convenience function to build an HTML radio button with a label
 442          *
 443          * @param string $label
 444          * @param string $name
 445          * @param string $value
 446          * @param string $id
 447          * @param bool $checked
 448          * @param array $attribs
 449          *
 450          * @return string HTML
 451          */
 452         public static function radioLabel( $label, $name, $value, $id,
 453                 $checked = false, $attribs = array()
 454         ) {
 455                 return self::radio( $name, $value, $checked, array( 'id' => $id ) + $attribs ) .
 456                         '&#160;' .
 457                         self::label( $label, $id, $attribs );
 458         }
 459
 460         /**
 461          * Convenience function to build an HTML submit button
 462          * When $wgUseMediaWikiUIEverywhere is true it will default to a constructive button
 463          * @param string $value Label text for the button
 464          * @param array $attribs Optional custom attributes
 465          * @return string HTML
 466          */
 467         public static function submitButton( $value, $attribs = array() ) {
 468                 global $wgUseMediaWikiUIEverywhere;
 469                 $baseAttrs = array(
 470                         'type' => 'submit',
 471                         'value' => $value,
 472                 );
 473                 // Done conditionally for time being as it is possible
 474                 // some submit forms
 475                 // might need to be mw-ui-destructive (e.g. delete a page)
 476                 if ( $wgUseMediaWikiUIEverywhere ) {
 477                         $baseAttrs['class'] = 'mw-ui-button mw-ui-constructive';
 478                 }
 479                 // Any custom attributes will take precendence of anything in baseAttrs e.g. override the class
 480                 $attribs = $attribs + $baseAttrs;
 481                 return Html::element( 'input', $attribs );
 482         }
 483
 484         /**
 485          * Convenience function to build an HTML drop-down list item.
 486          * @param string $text Text for this item. Will be HTML escaped
 487          * @param string $value Form submission value; if empty, use text
 488          * @param bool $selected If true, will be the default selected item
 489          * @param array $attribs Optional additional HTML attributes
 490          * @return string HTML
 491          */
 492         public static function option( $text, $value = null, $selected = false,
 493                         $attribs = array() ) {
 494                 if ( !is_null( $value ) ) {
 495                         $attribs['value'] = $value;
 496                 }
 497                 if ( $selected ) {
 498                         $attribs['selected'] = 'selected';
 499                 }
 500                 return Html::element( 'option', $attribs, $text );
 501         }
 502
 503         /**
 504          * Build a drop-down box from a textual list.
 505          *
 506          * @param string $name Name and id for the drop-down
 507          * @param string $list Correctly formatted text (newline delimited) to be
 508          *   used to generate the options.
 509          * @param string $other Text for the "Other reasons" option
 510          * @param string $selected Option which should be pre-selected
 511          * @param string $class CSS classes for the drop-down
 512          * @param int $tabindex Value of the tabindex attribute
 513          * @return string
 514          */
 515         public static function listDropDown( $name = '', $list = '', $other = '',
 516                 $selected = '', $class = '', $tabindex = null
 517         ) {
 518                 $optgroup = false;
 519
 520                 $options = self::option( $other, 'other', $selected === 'other' );
 521
 522                 foreach ( explode( "\n", $list ) as $option ) {
 523                         $value = trim( $option );
 524                         if ( $value == '' ) {
 525                                 continue;
 526                         } elseif ( substr( $value, 0, 1 ) == '*' && substr( $value, 1, 1 ) != '*' ) {
 527                                 // A new group is starting ...
 528                                 $value = trim( substr( $value, 1 ) );
 529                                 if ( $optgroup ) {
 530                                         $options .= self::closeElement( 'optgroup' );
 531                                 }
 532                                 $options .= self::openElement( 'optgroup', array( 'label' => $value ) );
 533                                 $optgroup = true;
 534                         } elseif ( substr( $value, 0, 2 ) == '**' ) {
 535                                 // groupmember
 536                                 $value = trim( substr( $value, 2 ) );
 537                                 $options .= self::option( $value, $value, $selected === $value );
 538                         } else {
 539                                 // groupless reason list
 540                                 if ( $optgroup ) {
 541                                         $options .= self::closeElement( 'optgroup' );
 542                                 }
 543                                 $options .= self::option( $value, $value, $selected === $value );
 544                                 $optgroup = false;
 545                         }
 546                 }
 547
 548                 if ( $optgroup ) {
 549                         $options .= self::closeElement( 'optgroup' );
 550                 }
 551
 552                 $attribs = array();
 553
 554                 if ( $name ) {
 555                         $attribs['id'] = $name;
 556                         $attribs['name'] = $name;
 557                 }
 558
 559                 if ( $class ) {
 560                         $attribs['class'] = $class;
 561                 }
 562
 563                 if ( $tabindex ) {
 564                         $attribs['tabindex'] = $tabindex;
 565                 }
 566
 567                 return Xml::openElement( 'select', $attribs )
 568                         . "\n"
 569                         . $options
 570                         . "\n"
 571                         . Xml::closeElement( 'select' );
 572         }
 573
 574         /**
 575          * Shortcut for creating fieldsets.
 576          *
 577          * @param string|bool $legend Legend of the fieldset. If evaluates to false,
 578          *   legend is not added.
 579          * @param string $content Pre-escaped content for the fieldset. If false,
 580          *   only open fieldset is returned.
 581          * @param array $attribs Any attributes to fieldset-element.
 582          *
 583          * @return string
 584          */
 585         public static function fieldset( $legend = false, $content = false, $attribs = array() ) {
 586                 $s = Xml::openElement( 'fieldset', $attribs ) . "\n";
 587
 588                 if ( $legend ) {
 589                         $s .= Xml::element( 'legend', null, $legend ) . "\n";
 590                 }
 591
 592                 if ( $content !== false ) {
 593                         $s .= $content . "\n";
 594                         $s .= Xml::closeElement( 'fieldset' ) . "\n";
 595                 }
 596
 597                 return $s;
 598         }
 599
 600         /**
 601          * Shortcut for creating textareas.
 602          *
 603          * @param string $name The 'name' for the textarea
 604          * @param string $content Content for the textarea
 605          * @param int $cols The number of columns for the textarea
 606          * @param int $rows The number of rows for the textarea
 607          * @param array $attribs Any other attributes for the textarea
 608          *
 609          * @return string
 610          */
 611         public static function textarea( $name, $content, $cols = 40, $rows = 5, $attribs = array() ) {
 612                 return self::element( 'textarea',
 613                                         Html::getTextInputAttributes(
 614                                                 array(
 615                                                         'name' => $name,
 616                                                         'id' => $name,
 617                                                         'cols' => $cols,
 618                                                         'rows' => $rows
 619                                                 ) + $attribs
 620                                         ),
 621                                         $content, false );
 622         }
 623
 624         /**
 625          * Returns an escaped string suitable for inclusion in a string literal
 626          * for JavaScript source code.
 627          * Illegal control characters are assumed not to be present.
 628          *
 629          * @deprecated since 1.21; use Xml::encodeJsVar() or Xml::encodeJsCall() instead
 630          * @param string $string String to escape
 631          * @return string
 632          */
 633         public static function escapeJsString( $string ) {
 634                 // See ECMA 262 section 7.8.4 for string literal format
 635                 $pairs = array(
 636                         "\\" => "\\\\",
 637                         "\"" => "\\\"",
 638                         '\'' => '\\\'',
 639                         "\n" => "\\n",
 640                         "\r" => "\\r",
 641
 642                         # To avoid closing the element or CDATA section
 643                         "<" => "\\x3c",
 644                         ">" => "\\x3e",
 645
 646                         # To avoid any complaints about bad entity refs
 647                         "&" => "\\x26",
 648
 649                         # Work around https://bugzilla.mozilla.org/show_bug.cgi?id=274152
 650                         # Encode certain Unicode formatting chars so affected
 651                         # versions of Gecko don't misinterpret our strings;
 652                         # this is a common problem with Farsi text.
 653                         "\xe2\x80\x8c" => "\\u200c", // ZERO WIDTH NON-JOINER
 654                         "\xe2\x80\x8d" => "\\u200d", // ZERO WIDTH JOINER
 655                 );
 656
 657                 return strtr( $string, $pairs );
 658         }
 659
 660         /**
 661          * Encode a variable of arbitrary type to JavaScript.
 662          * If the value is an XmlJsCode object, pass through the object's value verbatim.
 663          *
 664          * @note Only use this function for generating JavaScript code. If generating output
 665          *       for a proper JSON parser, just call FormatJson::encode() directly.
 666          *
 667          * @param mixed $value The value being encoded. Can be any type except a resource.
 668          * @param bool $pretty If true, add non-significant whitespace to improve readability.
 669          * @return string|bool String if successful; false upon failure
 670          */
 671         public static function encodeJsVar( $value, $pretty = false ) {
 672                 if ( $value instanceof XmlJsCode ) {
 673                         return $value->value;
 674                 }
 675                 return FormatJson::encode( $value, $pretty, FormatJson::UTF8_OK );
 676         }
 677
 678         /**
 679          * Create a call to a JavaScript function. The supplied arguments will be
 680          * encoded using Xml::encodeJsVar().
 681          *
 682          * @since 1.17
 683          * @param string $name The name of the function to call, or a JavaScript expression
 684          *    which evaluates to a function object which is called.
 685          * @param array $args The arguments to pass to the function.
 686          * @param bool $pretty If true, add non-significant whitespace to improve readability.
 687          * @return string|bool String if successful; false upon failure
 688          */
 689         public static function encodeJsCall( $name, $args, $pretty = false ) {
 690                 foreach ( $args as &$arg ) {
 691                         $arg = Xml::encodeJsVar( $arg, $pretty );
 692                         if ( $arg === false ) {
 693                                 return false;
 694                         }
 695                 }
 696
 697                 return "$name(" . ( $pretty
 698                         ? ( ' ' . implode( ', ', $args ) . ' ' )
 699                         : implode( ',', $args )
 700                 ) . ");";
 701         }
 702
 703         /**
 704          * Check if a string is well-formed XML.
 705          * Must include the surrounding tag.
 706          * This function is a DoS vector if an attacker can define
 707          * entities in $text.
 708          *
 709          * @param string $text String to test.
 710          * @return bool
 711          *
 712          * @todo Error position reporting return
 713          */
 714         private static function isWellFormed( $text ) {
 715                 $parser = xml_parser_create( "UTF-8" );
 716
 717                 # case folding violates XML standard, turn it off
 718                 xml_parser_set_option( $parser, XML_OPTION_CASE_FOLDING, false );
 719
 720                 if ( !xml_parse( $parser, $text, true ) ) {
 721                         //$err = xml_error_string( xml_get_error_code( $parser ) );
 722                         //$position = xml_get_current_byte_index( $parser );
 723                         //$fragment = $this->extractFragment( $html, $position );
 724                         //$this->mXmlError = "$err at byte $position:\n$fragment";
 725                         xml_parser_free( $parser );
 726                         return false;
 727                 }
 728
 729                 xml_parser_free( $parser );
 730
 731                 return true;
 732         }
 733
 734         /**
 735          * Check if a string is a well-formed XML fragment.
 736          * Wraps fragment in an \<html\> bit and doctype, so it can be a fragment
 737          * and can use HTML named entities.
 738          *
 739          * @param string $text
 740          * @return bool
 741          */
 742         public static function isWellFormedXmlFragment( $text ) {
 743                 $html =
 744                         Sanitizer::hackDocType() .
 745                         '<html>' .
 746                         $text .
 747                         '</html>';
 748
 749                 return Xml::isWellFormed( $html );
 750         }
 751
 752         /**
 753          * Replace " > and < with their respective HTML entities ( &quot;,
 754          * &gt;, &lt;)
 755          *
 756          * @param string $in Text that might contain HTML tags.
 757          * @return string Escaped string
 758          */
 759         public static function escapeTagsOnly( $in ) {
 760                 return str_replace(
 761                         array( '"', '>', '<' ),
 762                         array( '&quot;', '&gt;', '&lt;' ),
 763                         $in );
 764         }
 765
 766         /**
 767          * Generate a form (without the opening form element).
 768          * Output optionally includes a submit button.
 769          * @param array $fields Associative array, key is the name of a message that
 770          *   contains a description for the field, value is an HTML string
 771          *   containing the appropriate input.
 772          * @param string $submitLabel The name of a message containing a label for
 773          *   the submit button.
 774          * @param array $submitAttribs The attributes to add to the submit button
 775          * @return string HTML form.
 776          */
 777         public static function buildForm( $fields, $submitLabel = null, $submitAttribs = array() ) {
 778                 $form = '';
 779                 $form .= "<table><tbody>";
 780
 781                 foreach ( $fields as $labelmsg => $input ) {
 782                         $id = "mw-$labelmsg";
 783                         $form .= Xml::openElement( 'tr', array( 'id' => $id ) );
 784
 785                         // TODO use a <label> here for accessibility purposes - will need
 786                         // to either not use a table to build the form, or find the ID of
 787                         // the input somehow.
 788
 789                         $form .= Xml::tags( 'td', array( 'class' => 'mw-label' ), wfMessage( $labelmsg )->parse() );
 790                         $form .= Xml::openElement( 'td', array( 'class' => 'mw-input' ) )
 791                                 . $input . Xml::closeElement( 'td' );
 792                         $form .= Xml::closeElement( 'tr' );
 793                 }
 794
 795                 if ( $submitLabel ) {
 796                         $form .= Xml::openElement( 'tr' );
 797                         $form .= Xml::tags( 'td', array(), '' );
 798                         $form .= Xml::openElement( 'td', array( 'class' => 'mw-submit' ) )
 799                                 . Xml::submitButton( wfMessage( $submitLabel )->text(), $submitAttribs )
 800                                 . Xml::closeElement( 'td' );
 801                         $form .= Xml::closeElement( 'tr' );
 802                 }
 803
 804                 $form .= "</tbody></table>";
 805
 806                 return $form;
 807         }
 808
 809         /**
 810          * Build a table of data
 811          * @param array $rows An array of arrays of strings, each to be a row in a table
 812          * @param array $attribs An array of attributes to apply to the table tag [optional]
 813          * @param array $headers An array of strings to use as table headers [optional]
 814          * @return string
 815          */
 816         public static function buildTable( $rows, $attribs = array(), $headers = null ) {
 817                 $s = Xml::openElement( 'table', $attribs );
 818
 819                 if ( is_array( $headers ) ) {
 820                         $s .= Xml::openElement( 'thead', $attribs );
 821
 822                         foreach ( $headers as $id => $header ) {
 823                                 $attribs = array();
 824
 825                                 if ( is_string( $id ) ) {
 826                                         $attribs['id'] = $id;
 827                                 }
 828
 829                                 $s .= Xml::element( 'th', $attribs, $header );
 830                         }
 831                         $s .= Xml::closeElement( 'thead' );
 832                 }
 833
 834                 foreach ( $rows as $id => $row ) {
 835                         $attribs = array();
 836
 837                         if ( is_string( $id ) ) {
 838                                 $attribs['id'] = $id;
 839                         }
 840
 841                         $s .= Xml::buildTableRow( $attribs, $row );
 842                 }
 843
 844                 $s .= Xml::closeElement( 'table' );
 845
 846                 return $s;
 847         }
 848
 849         /**
 850          * Build a row for a table
 851          * @param array $attribs An array of attributes to apply to the tr tag
 852          * @param array $cells An array of strings to put in <td>
 853          * @return string
 854          */
 855         public static function buildTableRow( $attribs, $cells ) {
 856                 $s = Xml::openElement( 'tr', $attribs );
 857
 858                 foreach ( $cells as $id => $cell ) {
 859                         $attribs = array();
 860
 861                         if ( is_string( $id ) ) {
 862                                 $attribs['id'] = $id;
 863                         }
 864
 865                         $s .= Xml::element( 'td', $attribs, $cell );
 866                 }
 867
 868                 $s .= Xml::closeElement( 'tr' );
 869
 870                 return $s;
 871         }
 872 }
 873
 874 /**
 875  * A wrapper class which causes Xml::encodeJsVar() and Xml::encodeJsCall() to
 876  * interpret a given string as being a JavaScript expression, instead of string
 877  * data.
 878  *
 879  * Example:
 880  *
 881  *    Xml::encodeJsVar( new XmlJsCode( 'a + b' ) );
 882  *
 883  * Returns "a + b".
 884  *
 885  * @note As of 1.21, XmlJsCode objects cannot be nested inside objects or arrays. The sole
 886  *       exception is the $args argument to Xml::encodeJsCall() because Xml::encodeJsVar() is
 887  *       called for each individual element in that array.
 888  *
 889  * @since 1.17
 890  */
 891 class XmlJsCode {
 892         public $value;
 893
 894         function __construct( $value ) {
 895                 $this->value = $value;
 896         }
 897 }