includes/Html.php

   1 <?php
   2 /**
   3  * Collection of methods to generate HTML content
   4  *
   5  * Copyright © 2009 Aryeh Gregor
   6  * http://www.mediawiki.org/
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; if not, write to the Free Software Foundation, Inc.,
  20  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  21  * http://www.gnu.org/copyleft/gpl.html
  22  *
  23  * @file
  24  */
  25
  26 /**
  27  * This class is a collection of static functions that serve two purposes:
  28  *
  29  * 1) Implement any algorithms specified by HTML5, or other HTML
  30  * specifications, in a convenient and self-contained way.
  31  *
  32  * 2) Allow HTML elements to be conveniently and safely generated, like the
  33  * current Xml class but a) less confused (Xml supports HTML-specific things,
  34  * but only sometimes!) and b) not necessarily confined to XML-compatible
  35  * output.
  36  *
  37  * There are two important configuration options this class uses:
  38  *
  39  * $wgHtml5: If this is set to false, then all output should be valid XHTML 1.0
  40  *     Transitional.
  41  * $wgWellFormedXml: If this is set to true, then all output should be
  42  *     well-formed XML (quotes on attributes, self-closing tags, etc.).
  43  *
  44  * This class is meant to be confined to utility functions that are called from
  45  * trusted code paths.  It does not do enforcement of policy like not allowing
  46  * <a> elements.
  47  *
  48  * @since 1.16
  49  */
  50 class Html {
  51         # List of void elements from HTML5, section 9.1.2 as of 2009-08-10
  52         private static $voidElements = array(
  53                 'area',
  54                 'base',
  55                 'br',
  56                 'col',
  57                 'command',
  58                 'embed',
  59                 'hr',
  60                 'img',
  61                 'input',
  62                 'keygen',
  63                 'link',
  64                 'meta',
  65                 'param',
  66                 'source',
  67         );
  68
  69         # Boolean attributes, which may have the value omitted entirely.  Manually
  70         # collected from the HTML5 spec as of 2010-06-07.
  71         private static $boolAttribs = array(
  72                 'async',
  73                 'autofocus',
  74                 'autoplay',
  75                 'checked',
  76                 'controls',
  77                 'defer',
  78                 'disabled',
  79                 'formnovalidate',
  80                 'hidden',
  81                 'ismap',
  82                 'itemscope',
  83                 'loop',
  84                 'multiple',
  85                 'novalidate',
  86                 'open',
  87                 'pubdate',
  88                 'readonly',
  89                 'required',
  90                 'reversed',
  91                 'scoped',
  92                 'seamless',
  93                 'selected',
  94         );
  95
  96         /**
  97          * Returns an HTML element in a string.  The major advantage here over
  98          * manually typing out the HTML is that it will escape all attribute
  99          * values.  If you're hardcoding all the attributes, or there are none, you
 100          * should probably type out the string yourself.
 101          *
 102          * This is quite similar to Xml::tags(), but it implements some useful
 103          * HTML-specific logic.  For instance, there is no $allowShortTag
 104          * parameter: the closing tag is magically omitted if $element has an empty
 105          * content model.  If $wgWellFormedXml is false, then a few bytes will be
 106          * shaved off the HTML output as well.  In the future, other HTML-specific
 107          * features might be added, like allowing arrays for the values of
 108          * attributes like class= and media=.
 109          *
 110          * @param $element string The element's name, e.g., 'a'
 111          * @param $attribs array  Associative array of attributes, e.g., array(
 112          *   'href' => 'http://www.mediawiki.org/' ).  See expandAttributes() for
 113          *   further documentation.
 114          * @param $contents string The raw HTML contents of the element: *not*
 115          *   escaped!
 116          * @return string Raw HTML
 117          */
 118         public static function rawElement( $element, $attribs = array(), $contents = '' ) {
 119                 global $wgWellFormedXml;
 120                 $start = self::openElement( $element, $attribs );
 121                 if ( in_array( $element, self::$voidElements ) ) {
 122                         if ( $wgWellFormedXml ) {
 123                                 # Silly XML.
 124                                 return substr( $start, 0, -1 ) . ' />';
 125                         }
 126                         return $start;
 127                 } else {
 128                         return "$start$contents" . self::closeElement( $element );
 129                 }
 130         }
 131
 132         /**
 133          * Identical to rawElement(), but HTML-escapes $contents (like
 134          * Xml::element()).
 135          *
 136          * @param $element string
 137          * @param $attribs array
 138          * @param $contents string
 139          *
 140          * @return string
 141          */
 142         public static function element( $element, $attribs = array(), $contents = '' ) {
 143                 return self::rawElement( $element, $attribs, strtr( $contents, array(
 144                         # There's no point in escaping quotes, >, etc. in the contents of
 145                         # elements.
 146                         '&' => '&amp;',
 147                         '<' => '&lt;'
 148                 ) ) );
 149         }
 150
 151         /**
 152          * Identical to rawElement(), but has no third parameter and omits the end
 153          * tag (and the self-closing '/' in XML mode for empty elements).
 154          *
 155          * @param $element string
 156          * @param $attribs array
 157          *
 158          * @return string
 159          */
 160         public static function openElement( $element, $attribs = array() ) {
 161                 global $wgHtml5, $wgWellFormedXml;
 162                 $attribs = (array)$attribs;
 163                 # This is not required in HTML5, but let's do it anyway, for
 164                 # consistency and better compression.
 165                 $element = strtolower( $element );
 166
 167                 # In text/html, initial <html> and <head> tags can be omitted under
 168                 # pretty much any sane circumstances, if they have no attributes.  See:
 169                 # <http://www.whatwg.org/specs/web-apps/current-work/multipage/syntax.html#optional-tags>
 170                 if ( !$wgWellFormedXml && !$attribs
 171                 && in_array( $element, array( 'html', 'head' ) ) ) {
 172                         return '';
 173                 }
 174
 175                 # Remove HTML5-only attributes if we aren't doing HTML5, and disable
 176                 # form validation regardless (see bug 23769 and the more detailed
 177                 # comment in expandAttributes())
 178                 if ( $element == 'input' ) {
 179                         # Whitelist of types that don't cause validation.  All except
 180                         # 'search' are valid in XHTML1.
 181                         $validTypes = array(
 182                                 'hidden',
 183                                 'text',
 184                                 'password',
 185                                 'checkbox',
 186                                 'radio',
 187                                 'file',
 188                                 'submit',
 189                                 'image',
 190                                 'reset',
 191                                 'button',
 192                                 'search',
 193                         );
 194
 195                         if ( isset( $attribs['type'] )
 196                         && !in_array( $attribs['type'], $validTypes ) ) {
 197                                 unset( $attribs['type'] );
 198                         }
 199
 200                         if ( isset( $attribs['type'] ) && $attribs['type'] == 'search'
 201                         && !$wgHtml5 ) {
 202                                 unset( $attribs['type'] );
 203                         }
 204                 }
 205
 206                 if ( !$wgHtml5 && $element == 'textarea' && isset( $attribs['maxlength'] ) ) {
 207                         unset( $attribs['maxlength'] );
 208                 }
 209
 210                 return "<$element" . self::expandAttributes(
 211                         self::dropDefaults( $element, $attribs ) ) . '>';
 212         }
 213
 214         /**
 215          * Returns "</$element>", except if $wgWellFormedXml is off, in which case
 216          * it returns the empty string when that's guaranteed to be safe.
 217          *
 218          * @since 1.17
 219          * @param $element string Name of the element, e.g., 'a'
 220          * @return string A closing tag, if required
 221          */
 222         public static function closeElement( $element ) {
 223                 global $wgWellFormedXml;
 224
 225                 $element = strtolower( $element );
 226
 227                 # Reference:
 228                 # http://www.whatwg.org/specs/web-apps/current-work/multipage/syntax.html#optional-tags
 229                 if ( !$wgWellFormedXml && in_array( $element, array(
 230                         'html',
 231                         'head',
 232                         'body',
 233                         'li',
 234                         'dt',
 235                         'dd',
 236                         'tr',
 237                         'td',
 238                         'th',
 239                 ) ) ) {
 240                         return '';
 241                 }
 242                 return "</$element>";
 243         }
 244
 245         /**
 246          * Given an element name and an associative array of element attributes,
 247          * return an array that is functionally identical to the input array, but
 248          * possibly smaller.  In particular, attributes might be stripped if they
 249          * are given their default values.
 250          *
 251          * This method is not guaranteed to remove all redundant attributes, only
 252          * some common ones and some others selected arbitrarily at random.  It
 253          * only guarantees that the output array should be functionally identical
 254          * to the input array (currently per the HTML 5 draft as of 2009-09-06).
 255          *
 256          * @param $element string Name of the element, e.g., 'a'
 257          * @param $attribs array  Associative array of attributes, e.g., array(
 258          *   'href' => 'http://www.mediawiki.org/' ).  See expandAttributes() for
 259          *   further documentation.
 260          * @return array An array of attributes functionally identical to $attribs
 261          */
 262         private static function dropDefaults( $element, $attribs ) {
 263                 # Don't bother doing anything if we aren't outputting HTML5; it's too
 264                 # much of a pain to maintain two sets of defaults.
 265                 global $wgHtml5;
 266                 if ( !$wgHtml5 ) {
 267                         return $attribs;
 268                 }
 269
 270                 static $attribDefaults = array(
 271                         'area' => array( 'shape' => 'rect' ),
 272                         'button' => array(
 273                                 'formaction' => 'GET',
 274                                 'formenctype' => 'application/x-www-form-urlencoded',
 275                                 'type' => 'submit',
 276                         ),
 277                         'canvas' => array(
 278                                 'height' => '150',
 279                                 'width' => '300',
 280                         ),
 281                         'command' => array( 'type' => 'command' ),
 282                         'form' => array(
 283                                 'action' => 'GET',
 284                                 'autocomplete' => 'on',
 285                                 'enctype' => 'application/x-www-form-urlencoded',
 286                         ),
 287                         'input' => array(
 288                                 'formaction' => 'GET',
 289                                 'type' => 'text',
 290                                 'value' => '',
 291                         ),
 292                         'keygen' => array( 'keytype' => 'rsa' ),
 293                         'link' => array( 'media' => 'all' ),
 294                         'menu' => array( 'type' => 'list' ),
 295                         # Note: the use of text/javascript here instead of other JavaScript
 296                         # MIME types follows the HTML5 spec.
 297                         'script' => array( 'type' => 'text/javascript' ),
 298                         'style' => array(
 299                                 'media' => 'all',
 300                                 'type' => 'text/css',
 301                         ),
 302                         'textarea' => array( 'wrap' => 'soft' ),
 303                 );
 304
 305                 $element = strtolower( $element );
 306
 307                 foreach ( $attribs as $attrib => $value ) {
 308                         $lcattrib = strtolower( $attrib );
 309                         $value = strval( $value );
 310
 311                         # Simple checks using $attribDefaults
 312                         if ( isset( $attribDefaults[$element][$lcattrib] ) &&
 313                         $attribDefaults[$element][$lcattrib] == $value ) {
 314                                 unset( $attribs[$attrib] );
 315                         }
 316
 317                         if ( $lcattrib == 'class' && $value == '' ) {
 318                                 unset( $attribs[$attrib] );
 319                         }
 320                 }
 321
 322                 # More subtle checks
 323                 if ( $element === 'link' && isset( $attribs['type'] )
 324                 && strval( $attribs['type'] ) == 'text/css' ) {
 325                         unset( $attribs['type'] );
 326                 }
 327                 if ( $element === 'select' && isset( $attribs['size'] ) ) {
 328                         if ( in_array( 'multiple', $attribs )
 329                                 || ( isset( $attribs['multiple'] ) && $attribs['multiple'] !== false )
 330                         ) {
 331                                 # A multi-select
 332                                 if ( strval( $attribs['size'] ) == '4' ) {
 333                                         unset( $attribs['size'] );
 334                                 }
 335                         } else {
 336                                 # Single select
 337                                 if ( strval( $attribs['size'] ) == '1' ) {
 338                                         unset( $attribs['size'] );
 339                                 }
 340                         }
 341                 }
 342
 343                 return $attribs;
 344         }
 345
 346         /**
 347          * Given an associative array of element attributes, generate a string
 348          * to stick after the element name in HTML output.  Like array( 'href' =>
 349          * 'http://www.mediawiki.org/' ) becomes something like
 350          * ' href="http://www.mediawiki.org"'.  Again, this is like
 351          * Xml::expandAttributes(), but it implements some HTML-specific logic.
 352          * For instance, it will omit quotation marks if $wgWellFormedXml is false,
 353          * and will treat boolean attributes specially.
 354          *
 355          * @param $attribs array Associative array of attributes, e.g., array(
 356          *   'href' => 'http://www.mediawiki.org/' ).  Values will be HTML-escaped.
 357          *   A value of false means to omit the attribute.  For boolean attributes,
 358          *   you can omit the key, e.g., array( 'checked' ) instead of
 359          *   array( 'checked' => 'checked' ) or such.
 360          * @return string HTML fragment that goes between element name and '>'
 361          *   (starting with a space if at least one attribute is output)
 362          */
 363         public static function expandAttributes( $attribs ) {
 364                 global $wgHtml5, $wgWellFormedXml;
 365
 366                 $ret = '';
 367                 $attribs = (array)$attribs;
 368                 foreach ( $attribs as $key => $value ) {
 369                         if ( $value === false || is_null( $value ) ) {
 370                                 continue;
 371                         }
 372
 373                         # For boolean attributes, support array( 'foo' ) instead of
 374                         # requiring array( 'foo' => 'meaningless' ).
 375                         if ( is_int( $key )
 376                         && in_array( strtolower( $value ), self::$boolAttribs ) ) {
 377                                 $key = $value;
 378                         }
 379
 380                         # Not technically required in HTML5, but required in XHTML 1.0,
 381                         # and we'd like consistency and better compression anyway.
 382                         $key = strtolower( $key );
 383
 384                         # Bug 23769: Blacklist all form validation attributes for now.  Current
 385                         # (June 2010) WebKit has no UI, so the form just refuses to submit
 386                         # without telling the user why, which is much worse than failing
 387                         # server-side validation.  Opera is the only other implementation at
 388                         # this time, and has ugly UI, so just kill the feature entirely until
 389                         # we have at least one good implementation.
 390                         if ( in_array( $key, array( 'max', 'min', 'pattern', 'required', 'step' ) ) ) {
 391                                 continue;
 392                         }
 393
 394                         # Here we're blacklisting some HTML5-only attributes...
 395                         if ( !$wgHtml5 && in_array( $key, array(
 396                                         'autocomplete',
 397                                         'autofocus',
 398                                         'max',
 399                                         'min',
 400                                         'multiple',
 401                                         'pattern',
 402                                         'placeholder',
 403                                         'required',
 404                                         'step',
 405                                         'spellcheck',
 406                         ) ) ) {
 407                                 continue;
 408                         }
 409
 410                         # See the "Attributes" section in the HTML syntax part of HTML5,
 411                         # 9.1.2.3 as of 2009-08-10.  Most attributes can have quotation
 412                         # marks omitted, but not all.  (Although a literal " is not
 413                         # permitted, we don't check for that, since it will be escaped
 414                         # anyway.)
 415                         #
 416                         # See also research done on further characters that need to be
 417                         # escaped: http://code.google.com/p/html5lib/issues/detail?id=93
 418                         $badChars = "\\x00- '=<>`/\x{00a0}\x{1680}\x{180e}\x{180F}\x{2000}\x{2001}"
 419                                 . "\x{2002}\x{2003}\x{2004}\x{2005}\x{2006}\x{2007}\x{2008}\x{2009}"
 420                                 . "\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}";
 421                         if ( $wgWellFormedXml || $value === ''
 422                         || preg_match( "![$badChars]!u", $value ) ) {
 423                                 $quote = '"';
 424                         } else {
 425                                 $quote = '';
 426                         }
 427
 428                         if ( in_array( $key, self::$boolAttribs ) ) {
 429                                 # In XHTML 1.0 Transitional, the value needs to be equal to the
 430                                 # key.  In HTML5, we can leave the value empty instead.  If we
 431                                 # don't need well-formed XML, we can omit the = entirely.
 432                                 if ( !$wgWellFormedXml ) {
 433                                         $ret .= " $key";
 434                                 } elseif ( $wgHtml5 ) {
 435                                         $ret .= " $key=\"\"";
 436                                 } else {
 437                                         $ret .= " $key=\"$key\"";
 438                                 }
 439                         } else {
 440                                 # Apparently we need to entity-encode \n, \r, \t, although the
 441                                 # spec doesn't mention that.  Since we're doing strtr() anyway,
 442                                 # and we don't need <> escaped here, we may as well not call
 443                                 # htmlspecialchars().
 444                                 # @todo FIXME: Verify that we actually need to
 445                                 # escape \n\r\t here, and explain why, exactly.
 446                                 #
 447                                 # We could call Sanitizer::encodeAttribute() for this, but we
 448                                 # don't because we're stubborn and like our marginal savings on
 449                                 # byte size from not having to encode unnecessary quotes.
 450                                 $map = array(
 451                                         '&' => '&amp;',
 452                                         '"' => '&quot;',
 453                                         "\n" => '&#10;',
 454                                         "\r" => '&#13;',
 455                                         "\t" => '&#9;'
 456                                 );
 457                                 if ( $wgWellFormedXml ) {
 458                                         # This is allowed per spec: <http://www.w3.org/TR/xml/#NT-AttValue>
 459                                         # But reportedly it breaks some XML tools?
 460                                         # @todo FIXME: Is this really true?
 461                                         $map['<'] = '&lt;';
 462                                 }
 463                                 $ret .= " $key=$quote" . strtr( $value, $map ) . $quote;
 464                         }
 465                 }
 466                 return $ret;
 467         }
 468
 469         /**
 470          * Output a <script> tag with the given contents.  TODO: do some useful
 471          * escaping as well, like if $contents contains literal '</script>' or (for
 472          * XML) literal "]]>".
 473          *
 474          * @param $contents string JavaScript
 475          * @return string Raw HTML
 476          */
 477         public static function inlineScript( $contents ) {
 478                 global $wgHtml5, $wgJsMimeType, $wgWellFormedXml;
 479
 480                 $attrs = array();
 481
 482                 if ( !$wgHtml5 ) {
 483                         $attrs['type'] = $wgJsMimeType;
 484                 }
 485
 486                 if ( $wgWellFormedXml && preg_match( '/[<&]/', $contents ) ) {
 487                         $contents = "/*<![CDATA[*/$contents/*]]>*/";
 488                 }
 489
 490                 return self::rawElement( 'script', $attrs, $contents );
 491         }
 492
 493         /**
 494          * Output a <script> tag linking to the given URL, e.g.,
 495          * <script src=foo.js></script>.
 496          *
 497          * @param $url string
 498          * @return string Raw HTML
 499          */
 500         public static function linkedScript( $url ) {
 501                 global $wgHtml5, $wgJsMimeType;
 502
 503                 $attrs = array( 'src' => $url );
 504
 505                 if ( !$wgHtml5 ) {
 506                         $attrs['type'] = $wgJsMimeType;
 507                 }
 508
 509                 return self::element( 'script', $attrs );
 510         }
 511
 512         /**
 513          * Output a <style> tag with the given contents for the given media type
 514          * (if any).  TODO: do some useful escaping as well, like if $contents
 515          * contains literal '</style>' (admittedly unlikely).
 516          *
 517          * @param $contents string CSS
 518          * @param $media mixed A media type string, like 'screen'
 519          * @return string Raw HTML
 520          */
 521         public static function inlineStyle( $contents, $media = 'all' ) {
 522                 global $wgWellFormedXml;
 523
 524                 if ( $wgWellFormedXml && preg_match( '/[<&]/', $contents ) ) {
 525                         $contents = "/*<![CDATA[*/$contents/*]]>*/";
 526                 }
 527
 528                 return self::rawElement( 'style', array(
 529                         'type' => 'text/css',
 530                         'media' => $media,
 531                 ), $contents );
 532         }
 533
 534         /**
 535          * Output a <link rel=stylesheet> linking to the given URL for the given
 536          * media type (if any).
 537          *
 538          * @param $url string
 539          * @param $media mixed A media type string, like 'screen'
 540          * @return string Raw HTML
 541          */
 542         public static function linkedStyle( $url, $media = 'all' ) {
 543                 return self::element( 'link', array(
 544                         'rel' => 'stylesheet',
 545                         'href' => $url,
 546                         'type' => 'text/css',
 547                         'media' => $media,
 548                 ) );
 549         }
 550
 551         /**
 552          * Convenience function to produce an <input> element.  This supports the
 553          * new HTML5 input types and attributes, and will silently strip them if
 554          * $wgHtml5 is false.
 555          *
 556          * @param $name    string name attribute
 557          * @param $value   mixed  value attribute
 558          * @param $type    string type attribute
 559          * @param $attribs array  Associative array of miscellaneous extra
 560          *   attributes, passed to Html::element()
 561          * @return string Raw HTML
 562          */
 563         public static function input( $name, $value = '', $type = 'text', $attribs = array() ) {
 564                 $attribs['type'] = $type;
 565                 $attribs['value'] = $value;
 566                 $attribs['name'] = $name;
 567
 568                 return self::element( 'input', $attribs );
 569         }
 570
 571         /**
 572          * Convenience function to produce an input element with type=hidden
 573          *
 574          * @param $name    string name attribute
 575          * @param $value   string value attribute
 576          * @param $attribs array  Associative array of miscellaneous extra
 577          *   attributes, passed to Html::element()
 578          * @return string Raw HTML
 579          */
 580         public static function hidden( $name, $value, $attribs = array() ) {
 581                 return self::input( $name, $value, 'hidden', $attribs );
 582         }
 583
 584         /**
 585          * Convenience function to produce an <input> element.  This supports leaving
 586          * out the cols= and rows= which Xml requires and are required by HTML4/XHTML
 587          * but not required by HTML5 and will silently set cols="" and rows="" if
 588          * $wgHtml5 is false and cols and rows are omitted (HTML4 validates present
 589          * but empty cols="" and rows="" as valid).
 590          *
 591          * @param $name    string name attribute
 592          * @param $value   string value attribute
 593          * @param $attribs array  Associative array of miscellaneous extra
 594          *   attributes, passed to Html::element()
 595          * @return string Raw HTML
 596          */
 597         public static function textarea( $name, $value = '', $attribs = array() ) {
 598                 global $wgHtml5;
 599
 600                 $attribs['name'] = $name;
 601
 602                 if ( !$wgHtml5 ) {
 603                         if ( !isset( $attribs['cols'] ) ) {
 604                                 $attribs['cols'] = "";
 605                         }
 606
 607                         if ( !isset( $attribs['rows'] ) ) {
 608                                 $attribs['rows'] = "";
 609                         }
 610                 }
 611
 612                 return self::element( 'textarea', $attribs, $value );
 613         }
 614
 615         /**
 616          * Constructs the opening html-tag with necessary doctypes depending on
 617          * global variables.
 618          *
 619          * @param $attribs array  Associative array of miscellaneous extra
 620          *   attributes, passed to Html::element() of html tag.
 621          * @return string  Raw HTML
 622          */
 623         public static function htmlHeader( $attribs = array() ) {
 624                 $ret = '';
 625
 626                 global $wgMimeType;
 627
 628                 if ( self::isXmlMimeType( $wgMimeType ) ) {
 629                         $ret .= "<?xml version=\"1.0\" encoding=\"UTF-8\" ?" . ">\n";
 630                 }
 631
 632                 global $wgHtml5, $wgHtml5Version, $wgDocType, $wgDTD;
 633                 global $wgXhtmlNamespaces, $wgXhtmlDefaultNamespace;
 634
 635                 if ( $wgHtml5 ) {
 636                         $ret .= "<!DOCTYPE html>\n";
 637
 638                         if ( $wgHtml5Version ) {
 639                                 $attribs['version'] = $wgHtml5Version;
 640                         }
 641                 } else {
 642                         $ret .= "<!DOCTYPE html PUBLIC \"$wgDocType\" \"$wgDTD\">\n";
 643                         $attribs['xmlns'] = $wgXhtmlDefaultNamespace;
 644
 645                         foreach ( $wgXhtmlNamespaces as $tag => $ns ) {
 646                                 $attribs["xmlns:$tag"] = $ns;
 647                         }
 648                 }
 649
 650                 $html = Html::openElement( 'html', $attribs );
 651
 652                 if ( $html ) {
 653                         $html .= "\n";
 654                 }
 655
 656                 $ret .= $html;
 657
 658                 return $ret;
 659         }
 660
 661         /**
 662          * Determines if the given mime type is xml.
 663          *
 664          * @param $mimetype    string MimeType
 665          * @return Boolean
 666          */
 667         public static function isXmlMimeType( $mimetype ) {
 668                 switch ( $mimetype ) {
 669                         case 'text/xml':
 670                         case 'application/xhtml+xml':
 671                         case 'application/xml':
 672                                 return true;
 673                         default:
 674                                 return false;
 675                 }
 676         }
 677
 678         /**
 679          * Get HTML for an info box with an icon.
 680          *
 681          * @param $text String: wikitext, get this with wfMsgNoTrans()
 682          * @param $icon String: icon name, file in skins/common/images
 683          * @param $alt String: alternate text for the icon
 684          * @param $class String: additional class name to add to the wrapper div
 685          * @param $useStylePath
 686          *
 687          * @return string
 688          */
 689         static function infoBox( $text, $icon, $alt, $class = false, $useStylePath = true ) {
 690                 global $wgStylePath;
 691
 692                 if ( $useStylePath ) {
 693                         $icon = $wgStylePath.'/common/images/'.$icon;
 694                 }
 695
 696                 $s  = Html::openElement( 'div', array( 'class' => "mw-infobox $class") );
 697
 698                 $s .= Html::openElement( 'div', array( 'class' => 'mw-infobox-left' ) ).
 699                                 Html::element( 'img',
 700                                         array(
 701                                                 'src' => $icon,
 702                                                 'alt' => $alt,
 703                                         )
 704                                 ).
 705                                 Html::closeElement( 'div' );
 706
 707                 $s .= Html::openElement( 'div', array( 'class' => 'mw-infobox-right' ) ).
 708                                 $text.
 709                                 Html::closeElement( 'div' );
 710                 $s .= Html::element( 'div', array( 'style' => 'clear: left;' ), ' ' );
 711
 712                 $s .= Html::closeElement( 'div' );
 713
 714                 $s .= Html::element( 'div', array( 'style' => 'clear: left;' ), ' ' );
 715
 716                 return $s;
 717         }
 718 }