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( $wgHtml5 ) {
 215                                 $validTypes = array_merge( $validTypes, array(
 216                                         'datetime',
 217                                         'datetime-local',
 218                                         'date',
 219                                         'month',
 220                                         'time',
 221                                         'week',
 222                                         'number',
 223                                         'range',
 224                                         'email',
 225                                         'url',
 226                                         'search',
 227                                         'tel',
 228                                         'color',
 229                                 ) );
 230                         }
 231                         if ( isset( $attribs['type'] )
 232                         && !in_array( $attribs['type'], $validTypes ) ) {
 233                                 unset( $attribs['type'] );
 234                         }
 235
 236                         if ( isset( $attribs['type'] ) && $attribs['type'] == 'search'
 237                         && !$wgHtml5 ) {
 238                                 unset( $attribs['type'] );
 239                         }
 240                 }
 241
 242                 if ( !$wgHtml5 && $element == 'textarea' && isset( $attribs['maxlength'] ) ) {
 243                         unset( $attribs['maxlength'] );
 244                 }
 245
 246                 return "<$element" . self::expandAttributes(
 247                         self::dropDefaults( $element, $attribs ) ) . '>';
 248         }
 249
 250         /**
 251          * Returns "</$element>", except if $wgWellFormedXml is off, in which case
 252          * it returns the empty string when that's guaranteed to be safe.
 253          *
 254          * @since 1.17
 255          * @param $element string Name of the element, e.g., 'a'
 256          * @return string A closing tag, if required
 257          */
 258         public static function closeElement( $element ) {
 259                 global $wgWellFormedXml;
 260
 261                 $element = strtolower( $element );
 262
 263                 # Reference:
 264                 # http://www.whatwg.org/specs/web-apps/current-work/multipage/syntax.html#optional-tags
 265                 if ( !$wgWellFormedXml && in_array( $element, array(
 266                         'html',
 267                         'head',
 268                         'body',
 269                         'li',
 270                         'dt',
 271                         'dd',
 272                         'tr',
 273                         'td',
 274                         'th',
 275                 ) ) ) {
 276                         return '';
 277                 }
 278                 return "</$element>";
 279         }
 280
 281         /**
 282          * Given an element name and an associative array of element attributes,
 283          * return an array that is functionally identical to the input array, but
 284          * possibly smaller.  In particular, attributes might be stripped if they
 285          * are given their default values.
 286          *
 287          * This method is not guaranteed to remove all redundant attributes, only
 288          * some common ones and some others selected arbitrarily at random.  It
 289          * only guarantees that the output array should be functionally identical
 290          * to the input array (currently per the HTML 5 draft as of 2009-09-06).
 291          *
 292          * @param $element string Name of the element, e.g., 'a'
 293          * @param $attribs array  Associative array of attributes, e.g., array(
 294          *   'href' => 'http://www.mediawiki.org/' ).  See expandAttributes() for
 295          *   further documentation.
 296          * @return array An array of attributes functionally identical to $attribs
 297          */
 298         private static function dropDefaults( $element, $attribs ) {
 299                 # Don't bother doing anything if we aren't outputting HTML5; it's too
 300                 # much of a pain to maintain two sets of defaults.
 301                 global $wgHtml5;
 302                 if ( !$wgHtml5 ) {
 303                         return $attribs;
 304                 }
 305
 306                 # Whenever altering this array, please provide a covering test case
 307                 # in HtmlTest::provideElementsWithAttributesHavingDefaultValues
 308                 static $attribDefaults = array(
 309                         'area' => array( 'shape' => 'rect' ),
 310                         'button' => array(
 311                                 'formaction' => 'GET',
 312                                 'formenctype' => 'application/x-www-form-urlencoded',
 313                                 'type' => 'submit',
 314                         ),
 315                         'canvas' => array(
 316                                 'height' => '150',
 317                                 'width' => '300',
 318                         ),
 319                         'command' => array( 'type' => 'command' ),
 320                         'form' => array(
 321                                 'action' => 'GET',
 322                                 'autocomplete' => 'on',
 323                                 'enctype' => 'application/x-www-form-urlencoded',
 324                         ),
 325                         'input' => array(
 326                                 'formaction' => 'GET',
 327                                 'type' => 'text',
 328                         ),
 329                         'keygen' => array( 'keytype' => 'rsa' ),
 330                         'link' => array( 'media' => 'all' ),
 331                         'menu' => array( 'type' => 'list' ),
 332                         # Note: the use of text/javascript here instead of other JavaScript
 333                         # MIME types follows the HTML5 spec.
 334                         'script' => array( 'type' => 'text/javascript' ),
 335                         'style' => array(
 336                                 'media' => 'all',
 337                                 'type' => 'text/css',
 338                         ),
 339                         'textarea' => array( 'wrap' => 'soft' ),
 340                 );
 341
 342                 $element = strtolower( $element );
 343
 344                 foreach ( $attribs as $attrib => $value ) {
 345                         $lcattrib = strtolower( $attrib );
 346                         if( is_array( $value ) ) {
 347                                 $value = implode( ' ', $value );
 348                         } else {
 349                                 $value = strval( $value );
 350                         }
 351
 352                         # Simple checks using $attribDefaults
 353                         if ( isset( $attribDefaults[$element][$lcattrib] ) &&
 354                         $attribDefaults[$element][$lcattrib] == $value ) {
 355                                 unset( $attribs[$attrib] );
 356                         }
 357
 358                         if ( $lcattrib == 'class' && $value == '' ) {
 359                                 unset( $attribs[$attrib] );
 360                         }
 361                 }
 362
 363                 # More subtle checks
 364                 if ( $element === 'link' && isset( $attribs['type'] )
 365                 && strval( $attribs['type'] ) == 'text/css' ) {
 366                         unset( $attribs['type'] );
 367                 }
 368                 if ( $element === 'input' ) {
 369                         $type = isset( $attribs['type'] ) ? $attribs['type'] : null;
 370                         $value = isset( $attribs['value'] ) ? $attribs['value'] : null;
 371                         if ( $type === 'checkbox' || $type === 'radio' ) {
 372                                 // The default value for checkboxes and radio buttons is 'on'
 373                                 // not ''. By stripping value="" we break radio boxes that
 374                                 // actually wants empty values.
 375                                 if ( $value === 'on' ) {
 376                                         unset( $attribs['value'] );
 377                                 }
 378                         } elseif ( $type === 'submit' ) {
 379                                 // The default value for submit appears to be "Submit" but
 380                                 // let's not bother stripping out localized text that matches
 381                                 // that.
 382                         } else {
 383                                 // The default value for nearly every other field type is ''
 384                                 // The 'range' and 'color' types use different defaults but
 385                                 // stripping a value="" does not hurt them.
 386                                 if ( $value === '' ) {
 387                                         unset( $attribs['value'] );
 388                                 }
 389                         }
 390                 }
 391                 if ( $element === 'select' && isset( $attribs['size'] ) ) {
 392                         if ( in_array( 'multiple', $attribs )
 393                                 || ( isset( $attribs['multiple'] ) && $attribs['multiple'] !== false )
 394                         ) {
 395                                 # A multi-select
 396                                 if ( strval( $attribs['size'] ) == '4' ) {
 397                                         unset( $attribs['size'] );
 398                                 }
 399                         } else {
 400                                 # Single select
 401                                 if ( strval( $attribs['size'] ) == '1' ) {
 402                                         unset( $attribs['size'] );
 403                                 }
 404                         }
 405                 }
 406
 407                 return $attribs;
 408         }
 409
 410         /**
 411          * Given an associative array of element attributes, generate a string
 412          * to stick after the element name in HTML output.  Like array( 'href' =>
 413          * 'http://www.mediawiki.org/' ) becomes something like
 414          * ' href="http://www.mediawiki.org"'.  Again, this is like
 415          * Xml::expandAttributes(), but it implements some HTML-specific logic.
 416          * For instance, it will omit quotation marks if $wgWellFormedXml is false,
 417          * and will treat boolean attributes specially.
 418          *
 419          * Attributes that should contain space-separated lists (such as 'class') array
 420          * values are allowed as well, which will automagically be normalized
 421          * and converted to a space-separated string. In addition to a numerical
 422          * array, the attribute value may also be an associative array. See the
 423          * example below for how that works.
 424          *
 425          * @par Numerical array
 426          * @code
 427          *     Html::element( 'em', array(
 428          *         'class' => array( 'foo', 'bar' )
 429          *     ) );
 430          *     // gives '<em class="foo bar"></em>'
 431          * @endcode
 432          *
 433          * @par Associative array
 434          * @code
 435          *     Html::element( 'em', array(
 436          *         'class' => array( 'foo', 'bar', 'foo' => false, 'quux' => true )
 437          *     ) );
 438          *     // gives '<em class="bar quux"></em>'
 439          * @endcode
 440          *
 441          * @param $attribs array Associative array of attributes, e.g., array(
 442          *   'href' => 'http://www.mediawiki.org/' ).  Values will be HTML-escaped.
 443          *   A value of false means to omit the attribute.  For boolean attributes,
 444          *   you can omit the key, e.g., array( 'checked' ) instead of
 445          *   array( 'checked' => 'checked' ) or such.
 446          * @return string HTML fragment that goes between element name and '>'
 447          *   (starting with a space if at least one attribute is output)
 448          */
 449         public static function expandAttributes( $attribs ) {
 450                 global $wgHtml5, $wgWellFormedXml;
 451
 452                 $ret = '';
 453                 $attribs = (array)$attribs;
 454                 foreach ( $attribs as $key => $value ) {
 455                         if ( $value === false || is_null( $value ) ) {
 456                                 continue;
 457                         }
 458
 459                         # For boolean attributes, support array( 'foo' ) instead of
 460                         # requiring array( 'foo' => 'meaningless' ).
 461                         if ( is_int( $key )
 462                         && in_array( strtolower( $value ), self::$boolAttribs ) ) {
 463                                 $key = $value;
 464                         }
 465
 466                         # Not technically required in HTML5, but required in XHTML 1.0,
 467                         # and we'd like consistency and better compression anyway.
 468                         $key = strtolower( $key );
 469
 470                         # Here we're blacklisting some HTML5-only attributes...
 471                         if ( !$wgHtml5 && in_array( $key, self::$HTMLFiveOnlyAttribs )
 472                          ) {
 473                                 continue;
 474                         }
 475
 476                         # Bug 23769: Blacklist all form validation attributes for now.  Current
 477                         # (June 2010) WebKit has no UI, so the form just refuses to submit
 478                         # without telling the user why, which is much worse than failing
 479                         # server-side validation.  Opera is the only other implementation at
 480                         # this time, and has ugly UI, so just kill the feature entirely until
 481                         # we have at least one good implementation.
 482                         if ( in_array( $key, array( 'max', 'min', 'pattern', 'required', 'step' ) ) ) {
 483                                 continue;
 484                         }
 485
 486                         // http://www.w3.org/TR/html401/index/attributes.html ("space-separated")
 487                         // http://www.w3.org/TR/html5/index.html#attributes-1 ("space-separated")
 488                         $spaceSeparatedListAttributes = array(
 489                                 'class', // html4, html5
 490                                 'accesskey', // as of html5, multiple space-separated values allowed
 491                                 // html4-spec doesn't document rel= as space-separated
 492                                 // but has been used like that and is now documented as such
 493                                 // in the html5-spec.
 494                                 'rel',
 495                         );
 496
 497                         # Specific features for attributes that allow a list of space-separated values
 498                         if ( in_array( $key, $spaceSeparatedListAttributes ) ) {
 499                                 // Apply some normalization and remove duplicates
 500
 501                                 // Convert into correct array. Array can contain space-seperated
 502                                 // values. Implode/explode to get those into the main array as well.
 503                                 if ( is_array( $value ) ) {
 504                                         // If input wasn't an array, we can skip this step
 505
 506                                         $newValue = array();
 507                                         foreach ( $value as $k => $v ) {
 508                                                 if ( is_string( $v ) ) {
 509                                                         // String values should be normal `array( 'foo' )`
 510                                                         // Just append them
 511                                                         if ( !isset( $value[$v] ) ) {
 512                                                                 // As a special case don't set 'foo' if a
 513                                                                 // separate 'foo' => true/false exists in the array
 514                                                                 // keys should be authoritive
 515                                                                 $newValue[] = $v;
 516                                                         }
 517                                                 } elseif ( $v ) {
 518                                                         // If the value is truthy but not a string this is likely
 519                                                         // an array( 'foo' => true ), falsy values don't add strings
 520                                                         $newValue[] = $k;
 521                                                 }
 522                                         }
 523                                         $value = implode( ' ', $newValue );
 524                                 }
 525                                 $value = explode( ' ', $value );
 526
 527                                 // Normalize spacing by fixing up cases where people used
 528                                 // more than 1 space and/or a trailing/leading space
 529                                 $value = array_diff( $value, array( '', ' ' ) );
 530
 531                                 // Remove duplicates and create the string
 532                                 $value = implode( ' ', array_unique( $value ) );
 533                         }
 534
 535                         # See the "Attributes" section in the HTML syntax part of HTML5,
 536                         # 9.1.2.3 as of 2009-08-10.  Most attributes can have quotation
 537                         # marks omitted, but not all.  (Although a literal " is not
 538                         # permitted, we don't check for that, since it will be escaped
 539                         # anyway.)
 540                         #
 541                         # See also research done on further characters that need to be
 542                         # escaped: http://code.google.com/p/html5lib/issues/detail?id=93
 543                         $badChars = "\\x00- '=<>`/\x{00a0}\x{1680}\x{180e}\x{180F}\x{2000}\x{2001}"
 544                                 . "\x{2002}\x{2003}\x{2004}\x{2005}\x{2006}\x{2007}\x{2008}\x{2009}"
 545                                 . "\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}";
 546                         if ( $wgWellFormedXml || $value === ''
 547                         || preg_match( "![$badChars]!u", $value ) ) {
 548                                 $quote = '"';
 549                         } else {
 550                                 $quote = '';
 551                         }
 552
 553                         if ( in_array( $key, self::$boolAttribs ) ) {
 554                                 # In XHTML 1.0 Transitional, the value needs to be equal to the
 555                                 # key.  In HTML5, we can leave the value empty instead.  If we
 556                                 # don't need well-formed XML, we can omit the = entirely.
 557                                 if ( !$wgWellFormedXml ) {
 558                                         $ret .= " $key";
 559                                 } elseif ( $wgHtml5 ) {
 560                                         $ret .= " $key=\"\"";
 561                                 } else {
 562                                         $ret .= " $key=\"$key\"";
 563                                 }
 564                         } else {
 565                                 # Apparently we need to entity-encode \n, \r, \t, although the
 566                                 # spec doesn't mention that.  Since we're doing strtr() anyway,
 567                                 # and we don't need <> escaped here, we may as well not call
 568                                 # htmlspecialchars().
 569                                 # @todo FIXME: Verify that we actually need to
 570                                 # escape \n\r\t here, and explain why, exactly.
 571                                 #
 572                                 # We could call Sanitizer::encodeAttribute() for this, but we
 573                                 # don't because we're stubborn and like our marginal savings on
 574                                 # byte size from not having to encode unnecessary quotes.
 575                                 $map = array(
 576                                         '&' => '&amp;',
 577                                         '"' => '&quot;',
 578                                         "\n" => '&#10;',
 579                                         "\r" => '&#13;',
 580                                         "\t" => '&#9;'
 581                                 );
 582                                 if ( $wgWellFormedXml ) {
 583                                         # This is allowed per spec: <http://www.w3.org/TR/xml/#NT-AttValue>
 584                                         # But reportedly it breaks some XML tools?
 585                                         # @todo FIXME: Is this really true?
 586                                         $map['<'] = '&lt;';
 587                                 }
 588
 589                                 $ret .= " $key=$quote" . strtr( $value, $map ) . $quote;
 590                         }
 591                 }
 592                 return $ret;
 593         }
 594
 595         /**
 596          * Output a "<script>" tag with the given contents.
 597          *
 598          * @todo do some useful escaping as well, like if $contents contains
 599          * literal "</script>" or (for XML) literal "]]>".
 600          *
 601          * @param $contents string JavaScript
 602          * @return string Raw HTML
 603          */
 604         public static function inlineScript( $contents ) {
 605                 global $wgHtml5, $wgJsMimeType, $wgWellFormedXml;
 606
 607                 $attrs = array();
 608
 609                 if ( !$wgHtml5 ) {
 610                         $attrs['type'] = $wgJsMimeType;
 611                 }
 612
 613                 if ( $wgWellFormedXml && preg_match( '/[<&]/', $contents ) ) {
 614                         $contents = "/*<![CDATA[*/$contents/*]]>*/";
 615                 }
 616
 617                 return self::rawElement( 'script', $attrs, $contents );
 618         }
 619
 620         /**
 621          * Output a "<script>" tag linking to the given URL, e.g.,
 622          * "<script src=foo.js></script>".
 623          *
 624          * @param $url string
 625          * @return string Raw HTML
 626          */
 627         public static function linkedScript( $url ) {
 628                 global $wgHtml5, $wgJsMimeType;
 629
 630                 $attrs = array( 'src' => $url );
 631
 632                 if ( !$wgHtml5 ) {
 633                         $attrs['type'] = $wgJsMimeType;
 634                 }
 635
 636                 return self::element( 'script', $attrs );
 637         }
 638
 639         /**
 640          * Output a "<style>" tag with the given contents for the given media type
 641          * (if any).  TODO: do some useful escaping as well, like if $contents
 642          * contains literal "</style>" (admittedly unlikely).
 643          *
 644          * @param $contents string CSS
 645          * @param $media mixed A media type string, like 'screen'
 646          * @return string Raw HTML
 647          */
 648         public static function inlineStyle( $contents, $media = 'all' ) {
 649                 global $wgWellFormedXml;
 650
 651                 if ( $wgWellFormedXml && preg_match( '/[<&]/', $contents ) ) {
 652                         $contents = "/*<![CDATA[*/$contents/*]]>*/";
 653                 }
 654
 655                 return self::rawElement( 'style', array(
 656                         'type' => 'text/css',
 657                         'media' => $media,
 658                 ), $contents );
 659         }
 660
 661         /**
 662          * Output a "<link rel=stylesheet>" linking to the given URL for the given
 663          * media type (if any).
 664          *
 665          * @param $url string
 666          * @param $media mixed A media type string, like 'screen'
 667          * @return string Raw HTML
 668          */
 669         public static function linkedStyle( $url, $media = 'all' ) {
 670                 return self::element( 'link', array(
 671                         'rel' => 'stylesheet',
 672                         'href' => $url,
 673                         'type' => 'text/css',
 674                         'media' => $media,
 675                 ) );
 676         }
 677
 678         /**
 679          * Convenience function to produce an "<input>" element.  This supports the
 680          * new HTML5 input types and attributes, and will silently strip them if
 681          * $wgHtml5 is false.
 682          *
 683          * @param $name    string name attribute
 684          * @param $value   mixed  value attribute
 685          * @param $type    string type attribute
 686          * @param $attribs array  Associative array of miscellaneous extra
 687          *   attributes, passed to Html::element()
 688          * @return string Raw HTML
 689          */
 690         public static function input( $name, $value = '', $type = 'text', $attribs = array() ) {
 691                 $attribs['type'] = $type;
 692                 $attribs['value'] = $value;
 693                 $attribs['name'] = $name;
 694
 695                 return self::element( 'input', $attribs );
 696         }
 697
 698         /**
 699          * Convenience function to produce an input element with type=hidden
 700          *
 701          * @param $name    string name attribute
 702          * @param $value   string value attribute
 703          * @param $attribs array  Associative array of miscellaneous extra
 704          *   attributes, passed to Html::element()
 705          * @return string Raw HTML
 706          */
 707         public static function hidden( $name, $value, $attribs = array() ) {
 708                 return self::input( $name, $value, 'hidden', $attribs );
 709         }
 710
 711         /**
 712          * Convenience function to produce an "<input>" element.
 713          *
 714          * This supports leaving out the cols= and rows= which Xml requires and are
 715          * required by HTML4/XHTML but not required by HTML5 and will silently set
 716          * cols="" and rows="" if $wgHtml5 is false and cols and rows are omitted
 717          * (HTML4 validates present but empty cols="" and rows="" as valid).
 718          *
 719          * @param $name    string name attribute
 720          * @param $value   string value attribute
 721          * @param $attribs array  Associative array of miscellaneous extra
 722          *   attributes, passed to Html::element()
 723          * @return string Raw HTML
 724          */
 725         public static function textarea( $name, $value = '', $attribs = array() ) {
 726                 global $wgHtml5;
 727
 728                 $attribs['name'] = $name;
 729
 730                 if ( !$wgHtml5 ) {
 731                         if ( !isset( $attribs['cols'] ) ) {
 732                                 $attribs['cols'] = "";
 733                         }
 734
 735                         if ( !isset( $attribs['rows'] ) ) {
 736                                 $attribs['rows'] = "";
 737                         }
 738                 }
 739
 740                 if (substr($value, 0, 1) == "\n") {
 741                         // Workaround for bug 12130: browsers eat the initial newline
 742                         // assuming that it's just for show, but they do keep the later
 743                         // newlines, which we may want to preserve during editing.
 744                         // Prepending a single newline
 745                         $spacedValue = "\n" . $value;
 746                 } else {
 747                         $spacedValue = $value;
 748                 }
 749                 return self::element( 'textarea', $attribs, $spacedValue );
 750         }
 751         /**
 752          * Build a drop-down box for selecting a namespace
 753          *
 754          * @param $params array:
 755          * - selected: [optional] Id of namespace which should be pre-selected
 756          * - all: [optional] Value of item for "all namespaces". If null or unset, no "<option>" is generated to select all namespaces
 757          * - label: text for label to add before the field
 758          * - exclude: [optional] Array of namespace ids to exclude
 759          * - disable: [optional] Array of namespace ids for which the option should be disabled in the selector
 760          * @param $selectAttribs array HTML attributes for the generated select element.
 761          * - id:   [optional], default: 'namespace'
 762          * - name: [optional], default: 'namespace'
 763          * @return string HTML code to select a namespace.
 764          */
 765         public static function namespaceSelector( Array $params = array(), Array $selectAttribs = array() ) {
 766                 global $wgContLang;
 767
 768                 ksort( $selectAttribs );
 769
 770                 // Is a namespace selected?
 771                 if ( isset( $params['selected'] ) ) {
 772                         // If string only contains digits, convert to clean int. Selected could also
 773                         // be "all" or "" etc. which needs to be left untouched.
 774                         // PHP is_numeric() has issues with large strings, PHP ctype_digit has other issues
 775                         // and returns false for already clean ints. Use regex instead..
 776                         if ( preg_match( '/^\d+$/', $params['selected'] ) ) {
 777                                 $params['selected'] = intval( $params['selected'] );
 778                         }
 779                         // else: leaves it untouched for later processing
 780                 } else {
 781                         $params['selected'] = '';
 782                 }
 783
 784                 if ( !isset( $params['exclude'] ) || !is_array( $params['exclude'] ) ) {
 785                         $params['exclude'] = array();
 786                 }
 787                 if ( !isset( $params['disable'] ) || !is_array( $params['disable'] ) ) {
 788                         $params['disable'] = array();
 789                 }
 790
 791                 // Associative array between option-values and option-labels
 792                 $options = array();
 793
 794                 if ( isset( $params['all'] ) ) {
 795                         // add an option that would let the user select all namespaces.
 796                         // Value is provided by user, the name shown is localized for the user.
 797                         $options[$params['all']] = wfMessage( 'namespacesall' )->text();
 798                 }
 799                 // Add all namespaces as options (in the content langauge)
 800                 $options += $wgContLang->getFormattedNamespaces();
 801
 802                 // Convert $options to HTML and filter out namespaces below 0
 803                 $optionsHtml = array();
 804                 foreach ( $options as $nsId => $nsName ) {
 805                         if ( $nsId < NS_MAIN || in_array( $nsId, $params['exclude'] ) ) {
 806                                 continue;
 807                         }
 808                         if ( $nsId === 0 ) {
 809                                 // For other namespaces use use the namespace prefix as label, but for
 810                                 // main we don't use "" but the user message descripting it (e.g. "(Main)" or "(Article)")
 811                                 $nsName = wfMessage( 'blanknamespace' )->text();
 812                         }
 813                         $optionsHtml[] = Html::element(
 814                                 'option', array(
 815                                         'disabled' => in_array( $nsId, $params['disable'] ),
 816                                         'value' => $nsId,
 817                                         'selected' => $nsId === $params['selected'],
 818                                 ), $nsName
 819                         );
 820                 }
 821
 822                 $ret = '';
 823                 if ( isset( $params['label'] ) ) {
 824                         $ret .= Html::element(
 825                                 'label', array(
 826                                         'for' => isset( $selectAttribs['id'] ) ? $selectAttribs['id'] : null,
 827                                 ), $params['label']
 828                         ) . '&#160;';
 829                 }
 830
 831                 // Wrap options in a <select>
 832                 $ret .= Html::openElement( 'select', $selectAttribs )
 833                         . "\n"
 834                         . implode( "\n", $optionsHtml )
 835                         . "\n"
 836                         . Html::closeElement( 'select' );
 837
 838                 return $ret;
 839         }
 840
 841         /**
 842          * Constructs the opening html-tag with necessary doctypes depending on
 843          * global variables.
 844          *
 845          * @param $attribs array  Associative array of miscellaneous extra
 846          *   attributes, passed to Html::element() of html tag.
 847          * @return string  Raw HTML
 848          */
 849         public static function htmlHeader( $attribs = array() ) {
 850                 $ret = '';
 851
 852                 global $wgMimeType;
 853
 854                 if ( self::isXmlMimeType( $wgMimeType ) ) {
 855                         $ret .= "<?xml version=\"1.0\" encoding=\"UTF-8\" ?" . ">\n";
 856                 }
 857
 858                 global $wgHtml5, $wgHtml5Version, $wgDocType, $wgDTD;
 859                 global $wgXhtmlNamespaces, $wgXhtmlDefaultNamespace;
 860
 861                 if ( $wgHtml5 ) {
 862                         $ret .= "<!DOCTYPE html>\n";
 863
 864                         if ( $wgHtml5Version ) {
 865                                 $attribs['version'] = $wgHtml5Version;
 866                         }
 867                 } else {
 868                         $ret .= "<!DOCTYPE html PUBLIC \"$wgDocType\" \"$wgDTD\">\n";
 869                         $attribs['xmlns'] = $wgXhtmlDefaultNamespace;
 870
 871                         foreach ( $wgXhtmlNamespaces as $tag => $ns ) {
 872                                 $attribs["xmlns:$tag"] = $ns;
 873                         }
 874                 }
 875
 876                 $html = Html::openElement( 'html', $attribs );
 877
 878                 if ( $html ) {
 879                         $html .= "\n";
 880                 }
 881
 882                 $ret .= $html;
 883
 884                 return $ret;
 885         }
 886
 887         /**
 888          * Determines if the given mime type is xml.
 889          *
 890          * @param $mimetype    string MimeType
 891          * @return Boolean
 892          */
 893         public static function isXmlMimeType( $mimetype ) {
 894                 switch ( $mimetype ) {
 895                         case 'text/xml':
 896                         case 'application/xhtml+xml':
 897                         case 'application/xml':
 898                                 return true;
 899                         default:
 900                                 return false;
 901                 }
 902         }
 903
 904         /**
 905          * Get HTML for an info box with an icon.
 906          *
 907          * @param $text String: wikitext, get this with wfMessage()->plain()
 908          * @param $icon String: icon name, file in skins/common/images
 909          * @param $alt String: alternate text for the icon
 910          * @param $class String: additional class name to add to the wrapper div
 911          * @param $useStylePath
 912          *
 913          * @return string
 914          */
 915         static function infoBox( $text, $icon, $alt, $class = false, $useStylePath = true ) {
 916                 global $wgStylePath;
 917
 918                 if ( $useStylePath ) {
 919                         $icon = $wgStylePath.'/common/images/'.$icon;
 920                 }
 921
 922                 $s  = Html::openElement( 'div', array( 'class' => "mw-infobox $class") );
 923
 924                 $s .= Html::openElement( 'div', array( 'class' => 'mw-infobox-left' ) ).
 925                                 Html::element( 'img',
 926                                         array(
 927                                                 'src' => $icon,
 928                                                 'alt' => $alt,
 929                                         )
 930                                 ).
 931                                 Html::closeElement( 'div' );
 932
 933                 $s .= Html::openElement( 'div', array( 'class' => 'mw-infobox-right' ) ).
 934                                 $text.
 935                                 Html::closeElement( 'div' );
 936                 $s .= Html::element( 'div', array( 'style' => 'clear: left;' ), ' ' );
 937
 938                 $s .= Html::closeElement( 'div' );
 939
 940                 $s .= Html::element( 'div', array( 'style' => 'clear: left;' ), ' ' );
 941
 942                 return $s;
 943         }
 944 }