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 8.1.2 as of 2011-08-12
  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                 'track',
  68                 'wbr',
  69         );
  70
  71         # Boolean attributes, which may have the value omitted entirely.  Manually
  72         # collected from the HTML5 spec as of 2011-08-12.
  73         private static $boolAttribs = array(
  74                 'async',
  75                 'autofocus',
  76                 'autoplay',
  77                 'checked',
  78                 'controls',
  79                 'default',
  80                 'defer',
  81                 'disabled',
  82                 'formnovalidate',
  83                 'hidden',
  84                 'ismap',
  85                 'itemscope',
  86                 'loop',
  87                 'multiple',
  88                 'muted',
  89                 'novalidate',
  90                 'open',
  91                 'pubdate',
  92                 'readonly',
  93                 'required',
  94                 'reversed',
  95                 'scoped',
  96                 'seamless',
  97                 'selected',
  98                 'truespeed',
  99                 'typemustmatch',
 100                 # HTML5 Microdata
 101                 'itemscope',
 102         );
 103
 104         private static $HTMLFiveOnlyAttribs = array(
 105                 'autocomplete',
 106                 'autofocus',
 107                 'max',
 108                 'min',
 109                 'multiple',
 110                 'pattern',
 111                 'placeholder',
 112                 'required',
 113                 'step',
 114                 'spellcheck',
 115         );
 116
 117         /**
 118          * Returns an HTML element in a string.  The major advantage here over
 119          * manually typing out the HTML is that it will escape all attribute
 120          * values.  If you're hardcoding all the attributes, or there are none, you
 121          * should probably just type out the html element yourself.
 122          *
 123          * This is quite similar to Xml::tags(), but it implements some useful
 124          * HTML-specific logic.  For instance, there is no $allowShortTag
 125          * parameter: the closing tag is magically omitted if $element has an empty
 126          * content model.  If $wgWellFormedXml is false, then a few bytes will be
 127          * shaved off the HTML output as well.
 128          *
 129          * @param $element string The element's name, e.g., 'a'
 130          * @param $attribs array  Associative array of attributes, e.g., array(
 131          *   'href' => 'http://www.mediawiki.org/' ). See expandAttributes() for
 132          *   further documentation.
 133          * @param $contents string The raw HTML contents of the element: *not*
 134          *   escaped!
 135          * @return string Raw HTML
 136          */
 137         public static function rawElement( $element, $attribs = array(), $contents = '' ) {
 138                 global $wgWellFormedXml;
 139                 $start = self::openElement( $element, $attribs );
 140                 if ( in_array( $element, self::$voidElements ) ) {
 141                         if ( $wgWellFormedXml ) {
 142                                 # Silly XML.
 143                                 return substr( $start, 0, -1 ) . ' />';
 144                         }
 145                         return $start;
 146                 } else {
 147                         return "$start$contents" . self::closeElement( $element );
 148                 }
 149         }
 150
 151         /**
 152          * Identical to rawElement(), but HTML-escapes $contents (like
 153          * Xml::element()).
 154          *
 155          * @param $element string
 156          * @param $attribs array
 157          * @param $contents string
 158          *
 159          * @return string
 160          */
 161         public static function element( $element, $attribs = array(), $contents = '' ) {
 162                 return self::rawElement( $element, $attribs, strtr( $contents, array(
 163                         # There's no point in escaping quotes, >, etc. in the contents of
 164                         # elements.
 165                         '&' => '&amp;',
 166                         '<' => '&lt;'
 167                 ) ) );
 168         }
 169
 170         /**
 171          * Identical to rawElement(), but has no third parameter and omits the end
 172          * tag (and the self-closing '/' in XML mode for empty elements).
 173          *
 174          * @param $element string
 175          * @param $attribs array
 176          *
 177          * @return string
 178          */
 179         public static function openElement( $element, $attribs = array() ) {
 180                 global $wgHtml5, $wgWellFormedXml;
 181                 $attribs = (array)$attribs;
 182                 # This is not required in HTML5, but let's do it anyway, for
 183                 # consistency and better compression.
 184                 $element = strtolower( $element );
 185
 186                 # In text/html, initial <html> and <head> tags can be omitted under
 187                 # pretty much any sane circumstances, if they have no attributes.  See:
 188                 # <http://www.whatwg.org/specs/web-apps/current-work/multipage/syntax.html#optional-tags>
 189                 if ( !$wgWellFormedXml && !$attribs
 190                 && in_array( $element, array( 'html', 'head' ) ) ) {
 191                         return '';
 192                 }
 193
 194                 # Remove HTML5-only attributes if we aren't doing HTML5, and disable
 195                 # form validation regardless (see bug 23769 and the more detailed
 196                 # comment in expandAttributes())
 197                 if ( $element == 'input' ) {
 198                         # Whitelist of types that don't cause validation.  All except
 199                         # 'search' are valid in XHTML1.
 200                         $validTypes = array(
 201                                 'hidden',
 202                                 'text',
 203                                 'password',
 204                                 'checkbox',
 205                                 'radio',
 206                                 'file',
 207                                 'submit',
 208                                 'image',
 209                                 'reset',
 210                                 'button',
 211                                 'search',
 212                         );
 213
 214                         if ( isset( $attribs['type'] )
 215                         && !in_array( $attribs['type'], $validTypes ) ) {
 216                                 unset( $attribs['type'] );
 217                         }
 218
 219                         if ( isset( $attribs['type'] ) && $attribs['type'] == 'search'
 220                         && !$wgHtml5 ) {
 221                                 unset( $attribs['type'] );
 222                         }
 223                 }
 224
 225                 if ( !$wgHtml5 && $element == 'textarea' && isset( $attribs['maxlength'] ) ) {
 226                         unset( $attribs['maxlength'] );
 227                 }
 228
 229                 return "<$element" . self::expandAttributes(
 230                         self::dropDefaults( $element, $attribs ) ) . '>';
 231         }
 232
 233         /**
 234          * Returns "</$element>", except if $wgWellFormedXml is off, in which case
 235          * it returns the empty string when that's guaranteed to be safe.
 236          *
 237          * @since 1.17
 238          * @param $element string Name of the element, e.g., 'a'
 239          * @return string A closing tag, if required
 240          */
 241         public static function closeElement( $element ) {
 242                 global $wgWellFormedXml;
 243
 244                 $element = strtolower( $element );
 245
 246                 # Reference:
 247                 # http://www.whatwg.org/specs/web-apps/current-work/multipage/syntax.html#optional-tags
 248                 if ( !$wgWellFormedXml && in_array( $element, array(
 249                         'html',
 250                         'head',
 251                         'body',
 252                         'li',
 253                         'dt',
 254                         'dd',
 255                         'tr',
 256                         'td',
 257                         'th',
 258                 ) ) ) {
 259                         return '';
 260                 }
 261                 return "</$element>";
 262         }
 263
 264         /**
 265          * Given an element name and an associative array of element attributes,
 266          * return an array that is functionally identical to the input array, but
 267          * possibly smaller.  In particular, attributes might be stripped if they
 268          * are given their default values.
 269          *
 270          * This method is not guaranteed to remove all redundant attributes, only
 271          * some common ones and some others selected arbitrarily at random.  It
 272          * only guarantees that the output array should be functionally identical
 273          * to the input array (currently per the HTML 5 draft as of 2009-09-06).
 274          *
 275          * @param $element string Name of the element, e.g., 'a'
 276          * @param $attribs array  Associative array of attributes, e.g., array(
 277          *   'href' => 'http://www.mediawiki.org/' ).  See expandAttributes() for
 278          *   further documentation.
 279          * @return array An array of attributes functionally identical to $attribs
 280          */
 281         private static function dropDefaults( $element, $attribs ) {
 282                 # Don't bother doing anything if we aren't outputting HTML5; it's too
 283                 # much of a pain to maintain two sets of defaults.
 284                 global $wgHtml5;
 285                 if ( !$wgHtml5 ) {
 286                         return $attribs;
 287                 }
 288
 289                 static $attribDefaults = array(
 290                         'area' => array( 'shape' => 'rect' ),
 291                         'button' => array(
 292                                 'formaction' => 'GET',
 293                                 'formenctype' => 'application/x-www-form-urlencoded',
 294                                 'type' => 'submit',
 295                         ),
 296                         'canvas' => array(
 297                                 'height' => '150',
 298                                 'width' => '300',
 299                         ),
 300                         'command' => array( 'type' => 'command' ),
 301                         'form' => array(
 302                                 'action' => 'GET',
 303                                 'autocomplete' => 'on',
 304                                 'enctype' => 'application/x-www-form-urlencoded',
 305                         ),
 306                         'input' => array(
 307                                 'formaction' => 'GET',
 308                                 'type' => 'text',
 309                                 'value' => '',
 310                         ),
 311                         'keygen' => array( 'keytype' => 'rsa' ),
 312                         'link' => array( 'media' => 'all' ),
 313                         'menu' => array( 'type' => 'list' ),
 314                         # Note: the use of text/javascript here instead of other JavaScript
 315                         # MIME types follows the HTML5 spec.
 316                         'script' => array( 'type' => 'text/javascript' ),
 317                         'style' => array(
 318                                 'media' => 'all',
 319                                 'type' => 'text/css',
 320                         ),
 321                         'textarea' => array( 'wrap' => 'soft' ),
 322                 );
 323
 324                 $element = strtolower( $element );
 325
 326                 foreach ( $attribs as $attrib => $value ) {
 327                         $lcattrib = strtolower( $attrib );
 328                         $value = strval( $value );
 329
 330                         # Simple checks using $attribDefaults
 331                         if ( isset( $attribDefaults[$element][$lcattrib] ) &&
 332                         $attribDefaults[$element][$lcattrib] == $value ) {
 333                                 unset( $attribs[$attrib] );
 334                         }
 335
 336                         if ( $lcattrib == 'class' && $value == '' ) {
 337                                 unset( $attribs[$attrib] );
 338                         }
 339                 }
 340
 341                 # More subtle checks
 342                 if ( $element === 'link' && isset( $attribs['type'] )
 343                 && strval( $attribs['type'] ) == 'text/css' ) {
 344                         unset( $attribs['type'] );
 345                 }
 346                 if ( $element === 'select' && isset( $attribs['size'] ) ) {
 347                         if ( in_array( 'multiple', $attribs )
 348                                 || ( isset( $attribs['multiple'] ) && $attribs['multiple'] !== false )
 349                         ) {
 350                                 # A multi-select
 351                                 if ( strval( $attribs['size'] ) == '4' ) {
 352                                         unset( $attribs['size'] );
 353                                 }
 354                         } else {
 355                                 # Single select
 356                                 if ( strval( $attribs['size'] ) == '1' ) {
 357                                         unset( $attribs['size'] );
 358                                 }
 359                         }
 360                 }
 361
 362                 return $attribs;
 363         }
 364
 365         /**
 366          * Given an associative array of element attributes, generate a string
 367          * to stick after the element name in HTML output.  Like array( 'href' =>
 368          * 'http://www.mediawiki.org/' ) becomes something like
 369          * ' href="http://www.mediawiki.org"'.  Again, this is like
 370          * Xml::expandAttributes(), but it implements some HTML-specific logic.
 371          * For instance, it will omit quotation marks if $wgWellFormedXml is false,
 372          * and will treat boolean attributes specially.
 373          *
 374          * Attributes that should contain space-separated lists (such as 'class') array
 375          * values are allowed as well, which will automagically be normalized
 376          * and converted to a space-separated string. In addition to a numerical
 377          * array, the attribute value may also be an associative array. See the
 378          * example below for how that works.
 379          *
 380          * @par Numerical array
 381          * @code
 382          *     Html::element( 'em', array(
 383          *         'class' => array( 'foo', 'bar' )
 384          *     ) );
 385          *     // gives '<em class="foo bar"></em>'
 386          * @endcode
 387          *
 388          * @par Associative array
 389          * @code
 390          *     Html::element( 'em', array(
 391          *         'class' => array( 'foo', 'bar', 'foo' => false, 'quux' => true )
 392          *     ) );
 393          *     // gives '<em class="bar quux"></em>'
 394          * @endcode
 395          *
 396          * @param $attribs array Associative array of attributes, e.g., array(
 397          *   'href' => 'http://www.mediawiki.org/' ).  Values will be HTML-escaped.
 398          *   A value of false means to omit the attribute.  For boolean attributes,
 399          *   you can omit the key, e.g., array( 'checked' ) instead of
 400          *   array( 'checked' => 'checked' ) or such.
 401          * @return string HTML fragment that goes between element name and '>'
 402          *   (starting with a space if at least one attribute is output)
 403          */
 404         public static function expandAttributes( $attribs ) {
 405                 global $wgHtml5, $wgWellFormedXml;
 406
 407                 $ret = '';
 408                 $attribs = (array)$attribs;
 409                 foreach ( $attribs as $key => $value ) {
 410                         if ( $value === false || is_null( $value ) ) {
 411                                 continue;
 412                         }
 413
 414                         # For boolean attributes, support array( 'foo' ) instead of
 415                         # requiring array( 'foo' => 'meaningless' ).
 416                         if ( is_int( $key )
 417                         && in_array( strtolower( $value ), self::$boolAttribs ) ) {
 418                                 $key = $value;
 419                         }
 420
 421                         # Not technically required in HTML5, but required in XHTML 1.0,
 422                         # and we'd like consistency and better compression anyway.
 423                         $key = strtolower( $key );
 424
 425                         # Here we're blacklisting some HTML5-only attributes...
 426                         if ( !$wgHtml5 && in_array( $key, self::$HTMLFiveOnlyAttribs )
 427                          ) {
 428                                 continue;
 429                         }
 430
 431                         # Bug 23769: Blacklist all form validation attributes for now.  Current
 432                         # (June 2010) WebKit has no UI, so the form just refuses to submit
 433                         # without telling the user why, which is much worse than failing
 434                         # server-side validation.  Opera is the only other implementation at
 435                         # this time, and has ugly UI, so just kill the feature entirely until
 436                         # we have at least one good implementation.
 437                         if ( in_array( $key, array( 'max', 'min', 'pattern', 'required', 'step' ) ) ) {
 438                                 continue;
 439                         }
 440
 441                         // http://www.w3.org/TR/html401/index/attributes.html ("space-separated")
 442                         // http://www.w3.org/TR/html5/index.html#attributes-1 ("space-separated")
 443                         $spaceSeparatedListAttributes = array(
 444                                 'class', // html4, html5
 445                                 'accesskey', // as of html5, multiple space-separated values allowed
 446                                 // html4-spec doesn't document rel= as space-separated
 447                                 // but has been used like that and is now documented as such
 448                                 // in the html5-spec.
 449                                 'rel',
 450                         );
 451
 452                         # Specific features for attributes that allow a list of space-separated values
 453                         if ( in_array( $key, $spaceSeparatedListAttributes ) ) {
 454                                 // Apply some normalization and remove duplicates
 455
 456                                 // Convert into correct array. Array can contain space-seperated
 457                                 // values. Implode/explode to get those into the main array as well.
 458                                 if ( is_array( $value ) ) {
 459                                         // If input wasn't an array, we can skip this step
 460
 461                                         $newValue = array();
 462                                         foreach ( $value as $k => $v ) {
 463                                                 if ( is_string( $v ) ) {
 464                                                         // String values should be normal `array( 'foo' )`
 465                                                         // Just append them
 466                                                         if ( !isset( $value[$v] ) ) {
 467                                                                 // As a special case don't set 'foo' if a
 468                                                                 // separate 'foo' => true/false exists in the array
 469                                                                 // keys should be authoritive
 470                                                                 $newValue[] = $v;
 471                                                         }
 472                                                 } elseif ( $v ) {
 473                                                         // If the value is truthy but not a string this is likely
 474                                                         // an array( 'foo' => true ), falsy values don't add strings
 475                                                         $newValue[] = $k;
 476                                                 }
 477                                         }
 478                                         $value = implode( ' ', $newValue );
 479                                 }
 480                                 $value = explode( ' ', $value );
 481
 482                                 // Normalize spacing by fixing up cases where people used
 483                                 // more than 1 space and/or a trailing/leading space
 484                                 $value = array_diff( $value, array( '', ' ' ) );
 485
 486                                 // Remove duplicates and create the string
 487                                 $value = implode( ' ', array_unique( $value ) );
 488                         }
 489
 490                         # See the "Attributes" section in the HTML syntax part of HTML5,
 491                         # 9.1.2.3 as of 2009-08-10.  Most attributes can have quotation
 492                         # marks omitted, but not all.  (Although a literal " is not
 493                         # permitted, we don't check for that, since it will be escaped
 494                         # anyway.)
 495                         #
 496                         # See also research done on further characters that need to be
 497                         # escaped: http://code.google.com/p/html5lib/issues/detail?id=93
 498                         $badChars = "\\x00- '=<>`/\x{00a0}\x{1680}\x{180e}\x{180F}\x{2000}\x{2001}"
 499                                 . "\x{2002}\x{2003}\x{2004}\x{2005}\x{2006}\x{2007}\x{2008}\x{2009}"
 500                                 . "\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}";
 501                         if ( $wgWellFormedXml || $value === ''
 502                         || preg_match( "![$badChars]!u", $value ) ) {
 503                                 $quote = '"';
 504                         } else {
 505                                 $quote = '';
 506                         }
 507
 508                         if ( in_array( $key, self::$boolAttribs ) ) {
 509                                 # In XHTML 1.0 Transitional, the value needs to be equal to the
 510                                 # key.  In HTML5, we can leave the value empty instead.  If we
 511                                 # don't need well-formed XML, we can omit the = entirely.
 512                                 if ( !$wgWellFormedXml ) {
 513                                         $ret .= " $key";
 514                                 } elseif ( $wgHtml5 ) {
 515                                         $ret .= " $key=\"\"";
 516                                 } else {
 517                                         $ret .= " $key=\"$key\"";
 518                                 }
 519                         } else {
 520                                 # Apparently we need to entity-encode \n, \r, \t, although the
 521                                 # spec doesn't mention that.  Since we're doing strtr() anyway,
 522                                 # and we don't need <> escaped here, we may as well not call
 523                                 # htmlspecialchars().
 524                                 # @todo FIXME: Verify that we actually need to
 525                                 # escape \n\r\t here, and explain why, exactly.
 526                                 #
 527                                 # We could call Sanitizer::encodeAttribute() for this, but we
 528                                 # don't because we're stubborn and like our marginal savings on
 529                                 # byte size from not having to encode unnecessary quotes.
 530                                 $map = array(
 531                                         '&' => '&amp;',
 532                                         '"' => '&quot;',
 533                                         "\n" => '&#10;',
 534                                         "\r" => '&#13;',
 535                                         "\t" => '&#9;'
 536                                 );
 537                                 if ( $wgWellFormedXml ) {
 538                                         # This is allowed per spec: <http://www.w3.org/TR/xml/#NT-AttValue>
 539                                         # But reportedly it breaks some XML tools?
 540                                         # @todo FIXME: Is this really true?
 541                                         $map['<'] = '&lt;';
 542                                 }
 543
 544                                 $ret .= " $key=$quote" . strtr( $value, $map ) . $quote;
 545                         }
 546                 }
 547                 return $ret;
 548         }
 549
 550         /**
 551          * Output a <script> tag with the given contents.  TODO: do some useful
 552          * escaping as well, like if $contents contains literal '</script>' or (for
 553          * XML) literal "]]>".
 554          *
 555          * @param $contents string JavaScript
 556          * @return string Raw HTML
 557          */
 558         public static function inlineScript( $contents ) {
 559                 global $wgHtml5, $wgJsMimeType, $wgWellFormedXml;
 560
 561                 $attrs = array();
 562
 563                 if ( !$wgHtml5 ) {
 564                         $attrs['type'] = $wgJsMimeType;
 565                 }
 566
 567                 if ( $wgWellFormedXml && preg_match( '/[<&]/', $contents ) ) {
 568                         $contents = "/*<![CDATA[*/$contents/*]]>*/";
 569                 }
 570
 571                 return self::rawElement( 'script', $attrs, $contents );
 572         }
 573
 574         /**
 575          * Output a <script> tag linking to the given URL, e.g.,
 576          * <script src=foo.js></script>.
 577          *
 578          * @param $url string
 579          * @return string Raw HTML
 580          */
 581         public static function linkedScript( $url ) {
 582                 global $wgHtml5, $wgJsMimeType;
 583
 584                 $attrs = array( 'src' => $url );
 585
 586                 if ( !$wgHtml5 ) {
 587                         $attrs['type'] = $wgJsMimeType;
 588                 }
 589
 590                 return self::element( 'script', $attrs );
 591         }
 592
 593         /**
 594          * Output a <style> tag with the given contents for the given media type
 595          * (if any).  TODO: do some useful escaping as well, like if $contents
 596          * contains literal '</style>' (admittedly unlikely).
 597          *
 598          * @param $contents string CSS
 599          * @param $media mixed A media type string, like 'screen'
 600          * @return string Raw HTML
 601          */
 602         public static function inlineStyle( $contents, $media = 'all' ) {
 603                 global $wgWellFormedXml;
 604
 605                 if ( $wgWellFormedXml && preg_match( '/[<&]/', $contents ) ) {
 606                         $contents = "/*<![CDATA[*/$contents/*]]>*/";
 607                 }
 608
 609                 return self::rawElement( 'style', array(
 610                         'type' => 'text/css',
 611                         'media' => $media,
 612                 ), $contents );
 613         }
 614
 615         /**
 616          * Output a <link rel=stylesheet> linking to the given URL for the given
 617          * media type (if any).
 618          *
 619          * @param $url string
 620          * @param $media mixed A media type string, like 'screen'
 621          * @return string Raw HTML
 622          */
 623         public static function linkedStyle( $url, $media = 'all' ) {
 624                 return self::element( 'link', array(
 625                         'rel' => 'stylesheet',
 626                         'href' => $url,
 627                         'type' => 'text/css',
 628                         'media' => $media,
 629                 ) );
 630         }
 631
 632         /**
 633          * Convenience function to produce an <input> element.  This supports the
 634          * new HTML5 input types and attributes, and will silently strip them if
 635          * $wgHtml5 is false.
 636          *
 637          * @param $name    string name attribute
 638          * @param $value   mixed  value attribute
 639          * @param $type    string type attribute
 640          * @param $attribs array  Associative array of miscellaneous extra
 641          *   attributes, passed to Html::element()
 642          * @return string Raw HTML
 643          */
 644         public static function input( $name, $value = '', $type = 'text', $attribs = array() ) {
 645                 $attribs['type'] = $type;
 646                 $attribs['value'] = $value;
 647                 $attribs['name'] = $name;
 648
 649                 return self::element( 'input', $attribs );
 650         }
 651
 652         /**
 653          * Convenience function to produce an input element with type=hidden
 654          *
 655          * @param $name    string name attribute
 656          * @param $value   string value attribute
 657          * @param $attribs array  Associative array of miscellaneous extra
 658          *   attributes, passed to Html::element()
 659          * @return string Raw HTML
 660          */
 661         public static function hidden( $name, $value, $attribs = array() ) {
 662                 return self::input( $name, $value, 'hidden', $attribs );
 663         }
 664
 665         /**
 666          * Convenience function to produce an <input> element.  This supports leaving
 667          * out the cols= and rows= which Xml requires and are required by HTML4/XHTML
 668          * but not required by HTML5 and will silently set cols="" and rows="" if
 669          * $wgHtml5 is false and cols and rows are omitted (HTML4 validates present
 670          * but empty cols="" and rows="" as valid).
 671          *
 672          * @param $name    string name attribute
 673          * @param $value   string value attribute
 674          * @param $attribs array  Associative array of miscellaneous extra
 675          *   attributes, passed to Html::element()
 676          * @return string Raw HTML
 677          */
 678         public static function textarea( $name, $value = '', $attribs = array() ) {
 679                 global $wgHtml5;
 680
 681                 $attribs['name'] = $name;
 682
 683                 if ( !$wgHtml5 ) {
 684                         if ( !isset( $attribs['cols'] ) ) {
 685                                 $attribs['cols'] = "";
 686                         }
 687
 688                         if ( !isset( $attribs['rows'] ) ) {
 689                                 $attribs['rows'] = "";
 690                         }
 691                 }
 692
 693                 if (substr($value, 0, 1) == "\n") {
 694                         // Workaround for bug 12130: browsers eat the initial newline
 695                         // assuming that it's just for show, but they do keep the later
 696                         // newlines, which we may want to preserve during editing.
 697                         // Prepending a single newline
 698                         $spacedValue = "\n" . $value;
 699                 } else {
 700                         $spacedValue = $value;
 701                 }
 702                 return self::element( 'textarea', $attribs, $spacedValue );
 703         }
 704         /**
 705          * Build a drop-down box for selecting a namespace
 706          *
 707          * @param $params array:
 708          * - selected: [optional] Id of namespace which should be pre-selected
 709          * - all: [optional] Value of item for "all namespaces". If null or unset, no <option> is generated to select all namespaces
 710          * - label: text for label to add before the field
 711          * - exclude: [optional] Array of namespace ids to exclude
 712          * - disable: [optional] Array of namespace ids for which the option should be disabled in the selector
 713          * @param $selectAttribs array HTML attributes for the generated select element.
 714          * - id:   [optional], default: 'namespace'
 715          * - name: [optional], default: 'namespace'
 716          * @return string HTML code to select a namespace.
 717          */
 718         public static function namespaceSelector( Array $params = array(), Array $selectAttribs = array() ) {
 719                 global $wgContLang;
 720
 721                 ksort( $selectAttribs );
 722
 723                 // Is a namespace selected?
 724                 if ( isset( $params['selected'] ) ) {
 725                         // If string only contains digits, convert to clean int. Selected could also
 726                         // be "all" or "" etc. which needs to be left untouched.
 727                         // PHP is_numeric() has issues with large strings, PHP ctype_digit has other issues
 728                         // and returns false for already clean ints. Use regex instead..
 729                         if ( preg_match( '/^\d+$/', $params['selected'] ) ) {
 730                                 $params['selected'] = intval( $params['selected'] );
 731                         }
 732                         // else: leaves it untouched for later processing
 733                 } else {
 734                         $params['selected'] = '';
 735                 }
 736
 737                 if ( !isset( $params['exclude'] ) || !is_array( $params['exclude'] ) ) {
 738                         $params['exclude'] = array();
 739                 }
 740                 if ( !isset( $params['disable'] ) || !is_array( $params['disable'] ) ) {
 741                         $params['disable'] = array();
 742                 }
 743
 744                 // Associative array between option-values and option-labels
 745                 $options = array();
 746
 747                 if ( isset( $params['all'] ) ) {
 748                         // add an option that would let the user select all namespaces.
 749                         // Value is provided by user, the name shown is localized for the user.
 750                         $options[$params['all']] = wfMsg( 'namespacesall' );
 751                 }
 752                 // Add all namespaces as options (in the content langauge)
 753                 $options += $wgContLang->getFormattedNamespaces();
 754
 755                 // Convert $options to HTML and filter out namespaces below 0
 756                 $optionsHtml = array();
 757                 foreach ( $options as $nsId => $nsName ) {
 758                         if ( $nsId < NS_MAIN || in_array( $nsId, $params['exclude'] ) ) {
 759                                 continue;
 760                         }
 761                         if ( $nsId === 0 ) {
 762                                 // For other namespaces use use the namespace prefix as label, but for
 763                                 // main we don't use "" but the user message descripting it (e.g. "(Main)" or "(Article)")
 764                                 $nsName = wfMsg( 'blanknamespace' );
 765                         }
 766                         $optionsHtml[] = Html::element(
 767                                 'option', array(
 768                                         'disabled' => in_array( $nsId, $params['disable'] ),
 769                                         'value' => $nsId,
 770                                         'selected' => $nsId === $params['selected'],
 771                                 ), $nsName
 772                         );
 773                 }
 774
 775                 $ret = '';
 776                 if ( isset( $params['label'] ) ) {
 777                         $ret .= Html::element(
 778                                 'label', array(
 779                                         'for' => isset( $selectAttribs['id'] ) ? $selectAttribs['id'] : null,
 780                                 ), $params['label']
 781                         ) . '&#160;';
 782                 }
 783
 784                 // Wrap options in a <select>
 785                 $ret .= Html::openElement( 'select', $selectAttribs )
 786                         . "\n"
 787                         . implode( "\n", $optionsHtml )
 788                         . "\n"
 789                         . Html::closeElement( 'select' );
 790
 791                 return $ret;
 792         }
 793
 794         /**
 795          * Constructs the opening html-tag with necessary doctypes depending on
 796          * global variables.
 797          *
 798          * @param $attribs array  Associative array of miscellaneous extra
 799          *   attributes, passed to Html::element() of html tag.
 800          * @return string  Raw HTML
 801          */
 802         public static function htmlHeader( $attribs = array() ) {
 803                 $ret = '';
 804
 805                 global $wgMimeType;
 806
 807                 if ( self::isXmlMimeType( $wgMimeType ) ) {
 808                         $ret .= "<?xml version=\"1.0\" encoding=\"UTF-8\" ?" . ">\n";
 809                 }
 810
 811                 global $wgHtml5, $wgHtml5Version, $wgDocType, $wgDTD;
 812                 global $wgXhtmlNamespaces, $wgXhtmlDefaultNamespace;
 813
 814                 if ( $wgHtml5 ) {
 815                         $ret .= "<!DOCTYPE html>\n";
 816
 817                         if ( $wgHtml5Version ) {
 818                                 $attribs['version'] = $wgHtml5Version;
 819                         }
 820                 } else {
 821                         $ret .= "<!DOCTYPE html PUBLIC \"$wgDocType\" \"$wgDTD\">\n";
 822                         $attribs['xmlns'] = $wgXhtmlDefaultNamespace;
 823
 824                         foreach ( $wgXhtmlNamespaces as $tag => $ns ) {
 825                                 $attribs["xmlns:$tag"] = $ns;
 826                         }
 827                 }
 828
 829                 $html = Html::openElement( 'html', $attribs );
 830
 831                 if ( $html ) {
 832                         $html .= "\n";
 833                 }
 834
 835                 $ret .= $html;
 836
 837                 return $ret;
 838         }
 839
 840         /**
 841          * Determines if the given mime type is xml.
 842          *
 843          * @param $mimetype    string MimeType
 844          * @return Boolean
 845          */
 846         public static function isXmlMimeType( $mimetype ) {
 847                 switch ( $mimetype ) {
 848                         case 'text/xml':
 849                         case 'application/xhtml+xml':
 850                         case 'application/xml':
 851                                 return true;
 852                         default:
 853                                 return false;
 854                 }
 855         }
 856
 857         /**
 858          * Get HTML for an info box with an icon.
 859          *
 860          * @param $text String: wikitext, get this with wfMsgNoTrans()
 861          * @param $icon String: icon name, file in skins/common/images
 862          * @param $alt String: alternate text for the icon
 863          * @param $class String: additional class name to add to the wrapper div
 864          * @param $useStylePath
 865          *
 866          * @return string
 867          */
 868         static function infoBox( $text, $icon, $alt, $class = false, $useStylePath = true ) {
 869                 global $wgStylePath;
 870
 871                 if ( $useStylePath ) {
 872                         $icon = $wgStylePath.'/common/images/'.$icon;
 873                 }
 874
 875                 $s  = Html::openElement( 'div', array( 'class' => "mw-infobox $class") );
 876
 877                 $s .= Html::openElement( 'div', array( 'class' => 'mw-infobox-left' ) ).
 878                                 Html::element( 'img',
 879                                         array(
 880                                                 'src' => $icon,
 881                                                 'alt' => $alt,
 882                                         )
 883                                 ).
 884                                 Html::closeElement( 'div' );
 885
 886                 $s .= Html::openElement( 'div', array( 'class' => 'mw-infobox-right' ) ).
 887                                 $text.
 888                                 Html::closeElement( 'div' );
 889                 $s .= Html::element( 'div', array( 'style' => 'clear: left;' ), ' ' );
 890
 891                 $s .= Html::closeElement( 'div' );
 892
 893                 $s .= Html::element( 'div', array( 'style' => 'clear: left;' ), ' ' );
 894
 895                 return $s;
 896         }
 897 }