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  * $wgMimeType: If this is set to an xml mimetype then output should be
  40  *     valid XHTML5.
  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         /**
 105          * Returns an HTML element in a string.  The major advantage here over
 106          * manually typing out the HTML is that it will escape all attribute
 107          * values.  If you're hardcoding all the attributes, or there are none, you
 108          * should probably just type out the html element yourself.
 109          *
 110          * This is quite similar to Xml::tags(), but it implements some useful
 111          * HTML-specific logic.  For instance, there is no $allowShortTag
 112          * parameter: the closing tag is magically omitted if $element has an empty
 113          * content model.  If $wgWellFormedXml is false, then a few bytes will be
 114          * shaved off the HTML output as well.
 115          *
 116          * @param string $element The element's name, e.g., 'a'
 117          * @param array $attribs  Associative array of attributes, e.g., array(
 118          *   'href' => 'http://www.mediawiki.org/' ). See expandAttributes() for
 119          *   further documentation.
 120          * @param string $contents The raw HTML contents of the element: *not*
 121          *   escaped!
 122          * @return string Raw HTML
 123          */
 124         public static function rawElement( $element, $attribs = array(), $contents = '' ) {
 125                 global $wgWellFormedXml;
 126                 $start = self::openElement( $element, $attribs );
 127                 if ( in_array( $element, self::$voidElements ) ) {
 128                         if ( $wgWellFormedXml ) {
 129                                 // Silly XML.
 130                                 return substr( $start, 0, -1 ) . ' />';
 131                         }
 132                         return $start;
 133                 } else {
 134                         return "$start$contents" . self::closeElement( $element );
 135                 }
 136         }
 137
 138         /**
 139          * Identical to rawElement(), but HTML-escapes $contents (like
 140          * Xml::element()).
 141          *
 142          * @param $element string
 143          * @param $attribs array
 144          * @param $contents string
 145          *
 146          * @return string
 147          */
 148         public static function element( $element, $attribs = array(), $contents = '' ) {
 149                 return self::rawElement( $element, $attribs, strtr( $contents, array(
 150                         // There's no point in escaping quotes, >, etc. in the contents of
 151                         // elements.
 152                         '&' => '&amp;',
 153                         '<' => '&lt;'
 154                 ) ) );
 155         }
 156
 157         /**
 158          * Identical to rawElement(), but has no third parameter and omits the end
 159          * tag (and the self-closing '/' in XML mode for empty elements).
 160          *
 161          * @param $element string
 162          * @param $attribs array
 163          *
 164          * @return string
 165          */
 166         public static function openElement( $element, $attribs = array() ) {
 167                 global $wgWellFormedXml;
 168                 $attribs = (array)$attribs;
 169                 // This is not required in HTML5, but let's do it anyway, for
 170                 // consistency and better compression.
 171                 $element = strtolower( $element );
 172
 173                 // In text/html, initial <html> and <head> tags can be omitted under
 174                 // pretty much any sane circumstances, if they have no attributes.  See:
 175                 // <http://www.whatwg.org/html/syntax.html#optional-tags>
 176                 if ( !$wgWellFormedXml && !$attribs
 177                 && in_array( $element, array( 'html', 'head' ) ) ) {
 178                         return '';
 179                 }
 180
 181                 // Remove invalid input types
 182                 if ( $element == 'input' ) {
 183                         $validTypes = array(
 184                                 'hidden',
 185                                 'text',
 186                                 'password',
 187                                 'checkbox',
 188                                 'radio',
 189                                 'file',
 190                                 'submit',
 191                                 'image',
 192                                 'reset',
 193                                 'button',
 194
 195                                 // HTML input types
 196                                 'datetime',
 197                                 'datetime-local',
 198                                 'date',
 199                                 'month',
 200                                 'time',
 201                                 'week',
 202                                 'number',
 203                                 'range',
 204                                 'email',
 205                                 'url',
 206                                 'search',
 207                                 'tel',
 208                                 'color',
 209                         );
 210                         if ( isset( $attribs['type'] )
 211                         && !in_array( $attribs['type'], $validTypes ) ) {
 212                                 unset( $attribs['type'] );
 213                         }
 214                 }
 215
 216                 // According to standard the default type for <button> elements is "submit".
 217                 // Depending on compatibility mode IE might use "button", instead.
 218                 // We enforce the standard "submit".
 219                 if ( $element == 'button' && !isset( $attribs['type'] ) ) {
 220                         $attribs['type'] = 'submit';
 221                 }
 222
 223                 return "<$element" . self::expandAttributes(
 224                         self::dropDefaults( $element, $attribs ) ) . '>';
 225         }
 226
 227         /**
 228          * Returns "</$element>", except if $wgWellFormedXml is off, in which case
 229          * it returns the empty string when that's guaranteed to be safe.
 230          *
 231          * @since 1.17
 232          * @param string $element Name of the element, e.g., 'a'
 233          * @return string A closing tag, if required
 234          */
 235         public static function closeElement( $element ) {
 236                 global $wgWellFormedXml;
 237
 238                 $element = strtolower( $element );
 239
 240                 // Reference:
 241                 // http://www.whatwg.org/html/syntax.html#optional-tags
 242                 if ( !$wgWellFormedXml && in_array( $element, array(
 243                         'html',
 244                         'head',
 245                         'body',
 246                         'li',
 247                         'dt',
 248                         'dd',
 249                         'tr',
 250                         'td',
 251                         'th',
 252                 ) ) ) {
 253                         return '';
 254                 }
 255                 return "</$element>";
 256         }
 257
 258         /**
 259          * Given an element name and an associative array of element attributes,
 260          * return an array that is functionally identical to the input array, but
 261          * possibly smaller.  In particular, attributes might be stripped if they
 262          * are given their default values.
 263          *
 264          * This method is not guaranteed to remove all redundant attributes, only
 265          * some common ones and some others selected arbitrarily at random.  It
 266          * only guarantees that the output array should be functionally identical
 267          * to the input array (currently per the HTML 5 draft as of 2009-09-06).
 268          *
 269          * @param string $element Name of the element, e.g., 'a'
 270          * @param array $attribs  Associative array of attributes, e.g., array(
 271          *   'href' => 'http://www.mediawiki.org/' ).  See expandAttributes() for
 272          *   further documentation.
 273          * @return array An array of attributes functionally identical to $attribs
 274          */
 275         private static function dropDefaults( $element, $attribs ) {
 276
 277                 // Whenever altering this array, please provide a covering test case
 278                 // in HtmlTest::provideElementsWithAttributesHavingDefaultValues
 279                 static $attribDefaults = array(
 280                         'area' => array( 'shape' => 'rect' ),
 281                         'button' => array(
 282                                 'formaction' => 'GET',
 283                                 'formenctype' => 'application/x-www-form-urlencoded',
 284                         ),
 285                         'canvas' => array(
 286                                 'height' => '150',
 287                                 'width' => '300',
 288                         ),
 289                         'command' => array( 'type' => 'command' ),
 290                         'form' => array(
 291                                 'action' => 'GET',
 292                                 'autocomplete' => 'on',
 293                                 'enctype' => 'application/x-www-form-urlencoded',
 294                         ),
 295                         'input' => array(
 296                                 'formaction' => 'GET',
 297                                 'type' => 'text',
 298                         ),
 299                         'keygen' => array( 'keytype' => 'rsa' ),
 300                         'link' => array( 'media' => 'all' ),
 301                         'menu' => array( 'type' => 'list' ),
 302                         // Note: the use of text/javascript here instead of other JavaScript
 303                         // MIME types follows the HTML5 spec.
 304                         'script' => array( 'type' => 'text/javascript' ),
 305                         'style' => array(
 306                                 'media' => 'all',
 307                                 'type' => 'text/css',
 308                         ),
 309                         'textarea' => array( 'wrap' => 'soft' ),
 310                 );
 311
 312                 $element = strtolower( $element );
 313
 314                 foreach ( $attribs as $attrib => $value ) {
 315                         $lcattrib = strtolower( $attrib );
 316                         if ( is_array( $value ) ) {
 317                                 $value = implode( ' ', $value );
 318                         } else {
 319                                 $value = strval( $value );
 320                         }
 321
 322                         // Simple checks using $attribDefaults
 323                         if ( isset( $attribDefaults[$element][$lcattrib] ) &&
 324                         $attribDefaults[$element][$lcattrib] == $value ) {
 325                                 unset( $attribs[$attrib] );
 326                         }
 327
 328                         if ( $lcattrib == 'class' && $value == '' ) {
 329                                 unset( $attribs[$attrib] );
 330                         }
 331                 }
 332
 333                 // More subtle checks
 334                 if ( $element === 'link' && isset( $attribs['type'] )
 335                 && strval( $attribs['type'] ) == 'text/css' ) {
 336                         unset( $attribs['type'] );
 337                 }
 338                 if ( $element === 'input' ) {
 339                         $type = isset( $attribs['type'] ) ? $attribs['type'] : null;
 340                         $value = isset( $attribs['value'] ) ? $attribs['value'] : null;
 341                         if ( $type === 'checkbox' || $type === 'radio' ) {
 342                                 // The default value for checkboxes and radio buttons is 'on'
 343                                 // not ''. By stripping value="" we break radio boxes that
 344                                 // actually wants empty values.
 345                                 if ( $value === 'on' ) {
 346                                         unset( $attribs['value'] );
 347                                 }
 348                         } elseif ( $type === 'submit' ) {
 349                                 // The default value for submit appears to be "Submit" but
 350                                 // let's not bother stripping out localized text that matches
 351                                 // that.
 352                         } else {
 353                                 // The default value for nearly every other field type is ''
 354                                 // The 'range' and 'color' types use different defaults but
 355                                 // stripping a value="" does not hurt them.
 356                                 if ( $value === '' ) {
 357                                         unset( $attribs['value'] );
 358                                 }
 359                         }
 360                 }
 361                 if ( $element === 'select' && isset( $attribs['size'] ) ) {
 362                         if ( in_array( 'multiple', $attribs )
 363                                 || ( isset( $attribs['multiple'] ) && $attribs['multiple'] !== false )
 364                         ) {
 365                                 // A multi-select
 366                                 if ( strval( $attribs['size'] ) == '4' ) {
 367                                         unset( $attribs['size'] );
 368                                 }
 369                         } else {
 370                                 // Single select
 371                                 if ( strval( $attribs['size'] ) == '1' ) {
 372                                         unset( $attribs['size'] );
 373                                 }
 374                         }
 375                 }
 376
 377                 return $attribs;
 378         }
 379
 380         /**
 381          * Given an associative array of element attributes, generate a string
 382          * to stick after the element name in HTML output.  Like array( 'href' =>
 383          * 'http://www.mediawiki.org/' ) becomes something like
 384          * ' href="http://www.mediawiki.org"'.  Again, this is like
 385          * Xml::expandAttributes(), but it implements some HTML-specific logic.
 386          * For instance, it will omit quotation marks if $wgWellFormedXml is false,
 387          * and will treat boolean attributes specially.
 388          *
 389          * Attributes that should contain space-separated lists (such as 'class') array
 390          * values are allowed as well, which will automagically be normalized
 391          * and converted to a space-separated string. In addition to a numerical
 392          * array, the attribute value may also be an associative array. See the
 393          * example below for how that works.
 394          *
 395          * @par Numerical array
 396          * @code
 397          *     Html::element( 'em', array(
 398          *         'class' => array( 'foo', 'bar' )
 399          *     ) );
 400          *     // gives '<em class="foo bar"></em>'
 401          * @endcode
 402          *
 403          * @par Associative array
 404          * @code
 405          *     Html::element( 'em', array(
 406          *         'class' => array( 'foo', 'bar', 'foo' => false, 'quux' => true )
 407          *     ) );
 408          *     // gives '<em class="bar quux"></em>'
 409          * @endcode
 410          *
 411          * @param array $attribs Associative array of attributes, e.g., array(
 412          *   'href' => 'http://www.mediawiki.org/' ).  Values will be HTML-escaped.
 413          *   A value of false means to omit the attribute.  For boolean attributes,
 414          *   you can omit the key, e.g., array( 'checked' ) instead of
 415          *   array( 'checked' => 'checked' ) or such.
 416          * @return string HTML fragment that goes between element name and '>'
 417          *   (starting with a space if at least one attribute is output)
 418          */
 419         public static function expandAttributes( $attribs ) {
 420                 global $wgWellFormedXml;
 421
 422                 $ret = '';
 423                 $attribs = (array)$attribs;
 424                 foreach ( $attribs as $key => $value ) {
 425                         if ( $value === false || is_null( $value ) ) {
 426                                 continue;
 427                         }
 428
 429                         // For boolean attributes, support array( 'foo' ) instead of
 430                         // requiring array( 'foo' => 'meaningless' ).
 431                         if ( is_int( $key )
 432                         && in_array( strtolower( $value ), self::$boolAttribs ) ) {
 433                                 $key = $value;
 434                         }
 435
 436                         // Not technically required in HTML5 but we'd like consistency
 437                         // and better compression anyway.
 438                         $key = strtolower( $key );
 439
 440                         // Bug 23769: Blacklist all form validation attributes for now.  Current
 441                         // (June 2010) WebKit has no UI, so the form just refuses to submit
 442                         // without telling the user why, which is much worse than failing
 443                         // server-side validation.  Opera is the only other implementation at
 444                         // this time, and has ugly UI, so just kill the feature entirely until
 445                         // we have at least one good implementation.
 446
 447                         // As the default value of "1" for "step" rejects decimal
 448                         // numbers to be entered in 'type="number"' fields, allow
 449                         // the special case 'step="any"'.
 450
 451                         if ( in_array( $key, array( 'max', 'min', 'pattern', 'required' ) ) ||
 452                                  $key === 'step' && $value !== 'any' ) {
 453                                 continue;
 454                         }
 455
 456                         // http://www.w3.org/TR/html401/index/attributes.html ("space-separated")
 457                         // http://www.w3.org/TR/html5/index.html#attributes-1 ("space-separated")
 458                         $spaceSeparatedListAttributes = array(
 459                                 'class', // html4, html5
 460                                 'accesskey', // as of html5, multiple space-separated values allowed
 461                                 // html4-spec doesn't document rel= as space-separated
 462                                 // but has been used like that and is now documented as such
 463                                 // in the html5-spec.
 464                                 'rel',
 465                         );
 466
 467                         // Specific features for attributes that allow a list of space-separated values
 468                         if ( in_array( $key, $spaceSeparatedListAttributes ) ) {
 469                                 // Apply some normalization and remove duplicates
 470
 471                                 // Convert into correct array. Array can contain space-separated
 472                                 // values. Implode/explode to get those into the main array as well.
 473                                 if ( is_array( $value ) ) {
 474                                         // If input wasn't an array, we can skip this step
 475                                         $newValue = array();
 476                                         foreach ( $value as $k => $v ) {
 477                                                 if ( is_string( $v ) ) {
 478                                                         // String values should be normal `array( 'foo' )`
 479                                                         // Just append them
 480                                                         if ( !isset( $value[$v] ) ) {
 481                                                                 // As a special case don't set 'foo' if a
 482                                                                 // separate 'foo' => true/false exists in the array
 483                                                                 // keys should be authoritative
 484                                                                 $newValue[] = $v;
 485                                                         }
 486                                                 } elseif ( $v ) {
 487                                                         // If the value is truthy but not a string this is likely
 488                                                         // an array( 'foo' => true ), falsy values don't add strings
 489                                                         $newValue[] = $k;
 490                                                 }
 491                                         }
 492                                         $value = implode( ' ', $newValue );
 493                                 }
 494                                 $value = explode( ' ', $value );
 495
 496                                 // Normalize spacing by fixing up cases where people used
 497                                 // more than 1 space and/or a trailing/leading space
 498                                 $value = array_diff( $value, array( '', ' ' ) );
 499
 500                                 // Remove duplicates and create the string
 501                                 $value = implode( ' ', array_unique( $value ) );
 502                         }
 503
 504                         // See the "Attributes" section in the HTML syntax part of HTML5,
 505                         // 9.1.2.3 as of 2009-08-10.  Most attributes can have quotation
 506                         // marks omitted, but not all.  (Although a literal " is not
 507                         // permitted, we don't check for that, since it will be escaped
 508                         // anyway.)
 509                         #
 510                         // See also research done on further characters that need to be
 511                         // escaped: http://code.google.com/p/html5lib/issues/detail?id=93
 512                         $badChars = "\\x00- '=<>`/\x{00a0}\x{1680}\x{180e}\x{180F}\x{2000}\x{2001}"
 513                                 . "\x{2002}\x{2003}\x{2004}\x{2005}\x{2006}\x{2007}\x{2008}\x{2009}"
 514                                 . "\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}";
 515                         if ( $wgWellFormedXml || $value === ''
 516                         || preg_match( "![$badChars]!u", $value ) ) {
 517                                 $quote = '"';
 518                         } else {
 519                                 $quote = '';
 520                         }
 521
 522                         if ( in_array( $key, self::$boolAttribs ) ) {
 523                                 // In HTML5, we can leave the value empty. If we don't need
 524                                 // well-formed XML, we can omit the = entirely.
 525                                 if ( !$wgWellFormedXml ) {
 526                                         $ret .= " $key";
 527                                 } else {
 528                                         $ret .= " $key=\"\"";
 529                                 }
 530                         } else {
 531                                 // Apparently we need to entity-encode \n, \r, \t, although the
 532                                 // spec doesn't mention that.  Since we're doing strtr() anyway,
 533                                 // and we don't need <> escaped here, we may as well not call
 534                                 // htmlspecialchars().
 535                                 // @todo FIXME: Verify that we actually need to
 536                                 // escape \n\r\t here, and explain why, exactly.
 537                                 #
 538                                 // We could call Sanitizer::encodeAttribute() for this, but we
 539                                 // don't because we're stubborn and like our marginal savings on
 540                                 // byte size from not having to encode unnecessary quotes.
 541                                 $map = array(
 542                                         '&' => '&amp;',
 543                                         '"' => '&quot;',
 544                                         "\n" => '&#10;',
 545                                         "\r" => '&#13;',
 546                                         "\t" => '&#9;'
 547                                 );
 548                                 if ( $wgWellFormedXml ) {
 549                                         // This is allowed per spec: <http://www.w3.org/TR/xml/#NT-AttValue>
 550                                         // But reportedly it breaks some XML tools?
 551                                         // @todo FIXME: Is this really true?
 552                                         $map['<'] = '&lt;';
 553                                 }
 554                                 $ret .= " $key=$quote" . strtr( $value, $map ) . $quote;
 555                         }
 556                 }
 557                 return $ret;
 558         }
 559
 560         /**
 561          * Output a "<script>" tag with the given contents.
 562          *
 563          * @todo do some useful escaping as well, like if $contents contains
 564          * literal "</script>" or (for XML) literal "]]>".
 565          *
 566          * @param string $contents JavaScript
 567          * @return string Raw HTML
 568          */
 569         public static function inlineScript( $contents ) {
 570                 global $wgWellFormedXml;
 571
 572                 $attrs = array();
 573
 574                 if ( $wgWellFormedXml && preg_match( '/[<&]/', $contents ) ) {
 575                         $contents = "/*<![CDATA[*/$contents/*]]>*/";
 576                 }
 577
 578                 return self::rawElement( 'script', $attrs, $contents );
 579         }
 580
 581         /**
 582          * Output a "<script>" tag linking to the given URL, e.g.,
 583          * "<script src=foo.js></script>".
 584          *
 585          * @param $url string
 586          * @return string Raw HTML
 587          */
 588         public static function linkedScript( $url ) {
 589                 $attrs = array( 'src' => $url );
 590
 591                 return self::element( 'script', $attrs );
 592         }
 593
 594         /**
 595          * Output a "<style>" tag with the given contents for the given media type
 596          * (if any).  TODO: do some useful escaping as well, like if $contents
 597          * contains literal "</style>" (admittedly unlikely).
 598          *
 599          * @param string $contents CSS
 600          * @param $media mixed A media type string, like 'screen'
 601          * @return string Raw HTML
 602          */
 603         public static function inlineStyle( $contents, $media = 'all' ) {
 604                 global $wgWellFormedXml;
 605
 606                 if ( $wgWellFormedXml && preg_match( '/[<&]/', $contents ) ) {
 607                         $contents = "/*<![CDATA[*/$contents/*]]>*/";
 608                 }
 609
 610                 return self::rawElement( 'style', array(
 611                         'type' => 'text/css',
 612                         'media' => $media,
 613                 ), $contents );
 614         }
 615
 616         /**
 617          * Output a "<link rel=stylesheet>" linking to the given URL for the given
 618          * media type (if any).
 619          *
 620          * @param $url string
 621          * @param $media mixed A media type string, like 'screen'
 622          * @return string Raw HTML
 623          */
 624         public static function linkedStyle( $url, $media = 'all' ) {
 625                 return self::element( 'link', array(
 626                         'rel' => 'stylesheet',
 627                         'href' => $url,
 628                         'type' => 'text/css',
 629                         'media' => $media,
 630                 ) );
 631         }
 632
 633         /**
 634          * Convenience function to produce an "<input>" element.  This supports the
 635          * new HTML5 input types and attributes.
 636          *
 637          * @param $name    string name attribute
 638          * @param $value   mixed  value attribute
 639          * @param $type    string type attribute
 640          * @param array $attribs  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 array $attribs  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.
 667          *
 668          * This supports leaving out the cols= and rows= which Xml requires and are
 669          * required by HTML4/XHTML but not required by HTML5.
 670          *
 671          * @param $name    string name attribute
 672          * @param $value   string value attribute
 673          * @param array $attribs  Associative array of miscellaneous extra
 674          *   attributes, passed to Html::element()
 675          * @return string Raw HTML
 676          */
 677         public static function textarea( $name, $value = '', $attribs = array() ) {
 678                 $attribs['name'] = $name;
 679
 680                 if ( substr( $value, 0, 1 ) == "\n" ) {
 681                         // Workaround for bug 12130: browsers eat the initial newline
 682                         // assuming that it's just for show, but they do keep the later
 683                         // newlines, which we may want to preserve during editing.
 684                         // Prepending a single newline
 685                         $spacedValue = "\n" . $value;
 686                 } else {
 687                         $spacedValue = $value;
 688                 }
 689                 return self::element( 'textarea', $attribs, $spacedValue );
 690         }
 691         /**
 692          * Build a drop-down box for selecting a namespace
 693          *
 694          * @param $params array:
 695          * - selected: [optional] Id of namespace which should be pre-selected
 696          * - all: [optional] Value of item for "all namespaces". If null or unset, no "<option>" is generated to select all namespaces
 697          * - label: text for label to add before the field
 698          * - exclude: [optional] Array of namespace ids to exclude
 699          * - disable: [optional] Array of namespace ids for which the option should be disabled in the selector
 700          * @param array $selectAttribs HTML attributes for the generated select element.
 701          * - id:   [optional], default: 'namespace'
 702          * - name: [optional], default: 'namespace'
 703          * @return string HTML code to select a namespace.
 704          */
 705         public static function namespaceSelector( array $params = array(), array $selectAttribs = array() ) {
 706                 global $wgContLang;
 707
 708                 ksort( $selectAttribs );
 709
 710                 // Is a namespace selected?
 711                 if ( isset( $params['selected'] ) ) {
 712                         // If string only contains digits, convert to clean int. Selected could also
 713                         // be "all" or "" etc. which needs to be left untouched.
 714                         // PHP is_numeric() has issues with large strings, PHP ctype_digit has other issues
 715                         // and returns false for already clean ints. Use regex instead..
 716                         if ( preg_match( '/^\d+$/', $params['selected'] ) ) {
 717                                 $params['selected'] = intval( $params['selected'] );
 718                         }
 719                         // else: leaves it untouched for later processing
 720                 } else {
 721                         $params['selected'] = '';
 722                 }
 723
 724                 if ( !isset( $params['exclude'] ) || !is_array( $params['exclude'] ) ) {
 725                         $params['exclude'] = array();
 726                 }
 727                 if ( !isset( $params['disable'] ) || !is_array( $params['disable'] ) ) {
 728                         $params['disable'] = array();
 729                 }
 730
 731                 // Associative array between option-values and option-labels
 732                 $options = array();
 733
 734                 if ( isset( $params['all'] ) ) {
 735                         // add an option that would let the user select all namespaces.
 736                         // Value is provided by user, the name shown is localized for the user.
 737                         $options[$params['all']] = wfMessage( 'namespacesall' )->text();
 738                 }
 739                 // Add all namespaces as options (in the content language)
 740                 $options += $wgContLang->getFormattedNamespaces();
 741
 742                 // Convert $options to HTML and filter out namespaces below 0
 743                 $optionsHtml = array();
 744                 foreach ( $options as $nsId => $nsName ) {
 745                         if ( $nsId < NS_MAIN || in_array( $nsId, $params['exclude'] ) ) {
 746                                 continue;
 747                         }
 748                         if ( $nsId === NS_MAIN ) {
 749                                 // For other namespaces use use the namespace prefix as label, but for
 750                                 // main we don't use "" but the user message describing it (e.g. "(Main)" or "(Article)")
 751                                 $nsName = wfMessage( 'blanknamespace' )->text();
 752                         } elseif ( is_int( $nsId ) ) {
 753                                 $nsName = $wgContLang->convertNamespace( $nsId );
 754                         }
 755                         $optionsHtml[] = Html::element(
 756                                 'option', array(
 757                                         'disabled' => in_array( $nsId, $params['disable'] ),
 758                                         'value' => $nsId,
 759                                         'selected' => $nsId === $params['selected'],
 760                                 ), $nsName
 761                         );
 762                 }
 763
 764                 if ( !array_key_exists( 'id', $selectAttribs ) ) {
 765                         $selectAttribs['id'] = 'namespace';
 766                 }
 767
 768                 if ( !array_key_exists( 'name', $selectAttribs ) ) {
 769                         $selectAttribs['name'] = 'namespace';
 770                 }
 771
 772                 $ret = '';
 773                 if ( isset( $params['label'] ) ) {
 774                         $ret .= Html::element(
 775                                 'label', array(
 776                                         'for' => isset( $selectAttribs['id'] ) ? $selectAttribs['id'] : null,
 777                                 ), $params['label']
 778                         ) . '&#160;';
 779                 }
 780
 781                 // Wrap options in a <select>
 782                 $ret .= Html::openElement( 'select', $selectAttribs )
 783                         . "\n"
 784                         . implode( "\n", $optionsHtml )
 785                         . "\n"
 786                         . Html::closeElement( 'select' );
 787
 788                 return $ret;
 789         }
 790
 791         /**
 792          * Constructs the opening html-tag with necessary doctypes depending on
 793          * global variables.
 794          *
 795          * @param array $attribs  Associative array of miscellaneous extra
 796          *   attributes, passed to Html::element() of html tag.
 797          * @return string  Raw HTML
 798          */
 799         public static function htmlHeader( $attribs = array() ) {
 800                 $ret = '';
 801
 802                 global $wgHtml5Version, $wgMimeType, $wgXhtmlNamespaces;
 803
 804                 $isXHTML = self::isXmlMimeType( $wgMimeType );
 805
 806                 if ( $isXHTML ) { // XHTML5
 807                         // XML mimetyped markup should have an xml header.
 808                         // However a DOCTYPE is not needed.
 809                         $ret .= "<?xml version=\"1.0\" encoding=\"UTF-8\" ?" . ">\n";
 810
 811                         // Add the standard xmlns
 812                         $attribs['xmlns'] = 'http://www.w3.org/1999/xhtml';
 813
 814                         // And support custom namespaces
 815                         foreach ( $wgXhtmlNamespaces as $tag => $ns ) {
 816                                 $attribs["xmlns:$tag"] = $ns;
 817                         }
 818                 } else { // HTML5
 819                         // DOCTYPE
 820                         $ret .= "<!DOCTYPE html>\n";
 821                 }
 822
 823                 if ( $wgHtml5Version ) {
 824                         $attribs['version'] = $wgHtml5Version;
 825                 }
 826
 827                 $html = Html::openElement( 'html', $attribs );
 828
 829                 if ( $html ) {
 830                         $html .= "\n";
 831                 }
 832
 833                 $ret .= $html;
 834
 835                 return $ret;
 836         }
 837
 838         /**
 839          * Determines if the given mime type is xml.
 840          *
 841          * @param $mimetype    string MimeType
 842          * @return Boolean
 843          */
 844         public static function isXmlMimeType( $mimetype ) {
 845                 # http://www.whatwg.org/html/infrastructure.html#xml-mime-type
 846                 # * text/xml
 847                 # * application/xml
 848                 # * Any mimetype with a subtype ending in +xml (this implicitly includes application/xhtml+xml)
 849                 return (bool) preg_match( '!^(text|application)/xml$|^.+/.+\+xml$!', $mimetype );
 850         }
 851
 852         /**
 853          * Get HTML for an info box with an icon.
 854          *
 855          * @param string $text wikitext, get this with wfMessage()->plain()
 856          * @param string $icon icon name, file in skins/common/images
 857          * @param string $alt alternate text for the icon
 858          * @param string $class additional class name to add to the wrapper div
 859          * @param $useStylePath
 860          *
 861          * @return string
 862          */
 863         static function infoBox( $text, $icon, $alt, $class = false, $useStylePath = true ) {
 864                 global $wgStylePath;
 865
 866                 if ( $useStylePath ) {
 867                         $icon = $wgStylePath . '/common/images/' . $icon;
 868                 }
 869
 870                 $s = Html::openElement( 'div', array( 'class' => "mw-infobox $class" ) );
 871
 872                 $s .= Html::openElement( 'div', array( 'class' => 'mw-infobox-left' ) ) .
 873                                 Html::element( 'img',
 874                                         array(
 875                                                 'src' => $icon,
 876                                                 'alt' => $alt,
 877                                         )
 878                                 ) .
 879                                 Html::closeElement( 'div' );
 880
 881                 $s .= Html::openElement( 'div', array( 'class' => 'mw-infobox-right' ) ) .
 882                                 $text .
 883                                 Html::closeElement( 'div' );
 884                 $s .= Html::element( 'div', array( 'style' => 'clear: left;' ), ' ' );
 885
 886                 $s .= Html::closeElement( 'div' );
 887
 888                 $s .= Html::element( 'div', array( 'style' => 'clear: left;' ), ' ' );
 889
 890                 return $s;
 891         }
 892
 893         /**
 894          * Generate a srcset attribute value from an array mapping pixel densities
 895          * to URLs. Note that srcset supports width and height values as well, which
 896          * are not used here.
 897          *
 898          * @param array $urls
 899          * @return string
 900          */
 901         static function srcSet( $urls ) {
 902                 $candidates = array();
 903                 foreach ( $urls as $density => $url ) {
 904                         // Image candidate syntax per current whatwg live spec, 2012-09-23:
 905                         // http://www.whatwg.org/html/embedded-content-1.html#attr-img-srcset
 906                         $candidates[] = "{$url} {$density}x";
 907                 }
 908                 return implode( ", ", $candidates );
 909         }
 910 }