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 MIME type 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          * Modifies a set of attributes meant for text input elements
 106          * and apply a set of default attributes.
 107          * Removes size attribute when $wgUseMediaWikiUIEverywhere enabled.
 108          * @param array $attrs An attribute array.
 109          * @return array $attrs A modified attribute array
 110          */
 111         public static function getTextInputAttributes( $attrs ) {
 112                 global $wgUseMediaWikiUIEverywhere;
 113                 if ( !$attrs ) {
 114                         $attrs = array();
 115                 }
 116                 if ( isset( $attrs['class'] ) ) {
 117                         if ( is_array( $attrs['class'] ) ) {
 118                                 $attrs['class'][] = 'mw-ui-input';
 119                         } else {
 120                                 $attrs['class'] .= ' mw-ui-input';
 121                         }
 122                 } else {
 123                         $attrs['class'] = 'mw-ui-input';
 124                 }
 125                 if ( $wgUseMediaWikiUIEverywhere ) {
 126                         // Note that size can effect the desired width rendering of mw-ui-input elements
 127                         // so it is removed. Left intact when mediawiki ui not enabled.
 128                         unset( $attrs['size'] );
 129                 }
 130                 return $attrs;
 131         }
 132
 133         /**
 134          * Returns an HTML element in a string.  The major advantage here over
 135          * manually typing out the HTML is that it will escape all attribute
 136          * values.  If you're hardcoding all the attributes, or there are none, you
 137          * should probably just type out the html element yourself.
 138          *
 139          * This is quite similar to Xml::tags(), but it implements some useful
 140          * HTML-specific logic.  For instance, there is no $allowShortTag
 141          * parameter: the closing tag is magically omitted if $element has an empty
 142          * content model.  If $wgWellFormedXml is false, then a few bytes will be
 143          * shaved off the HTML output as well.
 144          *
 145          * @param string $element The element's name, e.g., 'a'
 146          * @param array $attribs Associative array of attributes, e.g., array(
 147          *   'href' => 'http://www.mediawiki.org/' ). See expandAttributes() for
 148          *   further documentation.
 149          * @param string $contents The raw HTML contents of the element: *not*
 150          *   escaped!
 151          * @return string Raw HTML
 152          */
 153         public static function rawElement( $element, $attribs = array(), $contents = '' ) {
 154                 global $wgWellFormedXml;
 155                 $start = self::openElement( $element, $attribs );
 156                 if ( in_array( $element, self::$voidElements ) ) {
 157                         if ( $wgWellFormedXml ) {
 158                                 // Silly XML.
 159                                 return substr( $start, 0, -1 ) . ' />';
 160                         }
 161                         return $start;
 162                 } else {
 163                         return "$start$contents" . self::closeElement( $element );
 164                 }
 165         }
 166
 167         /**
 168          * Identical to rawElement(), but HTML-escapes $contents (like
 169          * Xml::element()).
 170          *
 171          * @param string $element
 172          * @param array $attribs
 173          * @param string $contents
 174          *
 175          * @return string
 176          */
 177         public static function element( $element, $attribs = array(), $contents = '' ) {
 178                 return self::rawElement( $element, $attribs, strtr( $contents, array(
 179                         // There's no point in escaping quotes, >, etc. in the contents of
 180                         // elements.
 181                         '&' => '&amp;',
 182                         '<' => '&lt;'
 183                 ) ) );
 184         }
 185
 186         /**
 187          * Identical to rawElement(), but has no third parameter and omits the end
 188          * tag (and the self-closing '/' in XML mode for empty elements).
 189          *
 190          * @param string $element
 191          * @param array $attribs
 192          *
 193          * @return string
 194          */
 195         public static function openElement( $element, $attribs = array() ) {
 196                 global $wgWellFormedXml;
 197                 $attribs = (array)$attribs;
 198                 // This is not required in HTML5, but let's do it anyway, for
 199                 // consistency and better compression.
 200                 $element = strtolower( $element );
 201
 202                 // In text/html, initial <html> and <head> tags can be omitted under
 203                 // pretty much any sane circumstances, if they have no attributes.  See:
 204                 // <http://www.whatwg.org/html/syntax.html#optional-tags>
 205                 if ( !$wgWellFormedXml && !$attribs
 206                 && in_array( $element, array( 'html', 'head' ) ) ) {
 207                         return '';
 208                 }
 209
 210                 // Remove invalid input types
 211                 if ( $element == 'input' ) {
 212                         $validTypes = array(
 213                                 'hidden',
 214                                 'text',
 215                                 'password',
 216                                 'checkbox',
 217                                 'radio',
 218                                 'file',
 219                                 'submit',
 220                                 'image',
 221                                 'reset',
 222                                 'button',
 223
 224                                 // HTML input types
 225                                 'datetime',
 226                                 'datetime-local',
 227                                 'date',
 228                                 'month',
 229                                 'time',
 230                                 'week',
 231                                 'number',
 232                                 'range',
 233                                 'email',
 234                                 'url',
 235                                 'search',
 236                                 'tel',
 237                                 'color',
 238                         );
 239                         if ( isset( $attribs['type'] )
 240                         && !in_array( $attribs['type'], $validTypes ) ) {
 241                                 unset( $attribs['type'] );
 242                         }
 243                 }
 244
 245                 // According to standard the default type for <button> elements is "submit".
 246                 // Depending on compatibility mode IE might use "button", instead.
 247                 // We enforce the standard "submit".
 248                 if ( $element == 'button' && !isset( $attribs['type'] ) ) {
 249                         $attribs['type'] = 'submit';
 250                 }
 251
 252                 return "<$element" . self::expandAttributes(
 253                         self::dropDefaults( $element, $attribs ) ) . '>';
 254         }
 255
 256         /**
 257          * Returns "</$element>"
 258          *
 259          * @since 1.17
 260          * @param string $element Name of the element, e.g., 'a'
 261          * @return string A closing tag
 262          */
 263         public static function closeElement( $element ) {
 264                 $element = strtolower( $element );
 265
 266                 return "</$element>";
 267         }
 268
 269         /**
 270          * Given an element name and an associative array of element attributes,
 271          * return an array that is functionally identical to the input array, but
 272          * possibly smaller.  In particular, attributes might be stripped if they
 273          * are given their default values.
 274          *
 275          * This method is not guaranteed to remove all redundant attributes, only
 276          * some common ones and some others selected arbitrarily at random.  It
 277          * only guarantees that the output array should be functionally identical
 278          * to the input array (currently per the HTML 5 draft as of 2009-09-06).
 279          *
 280          * @param string $element Name of the element, e.g., 'a'
 281          * @param array $attribs Associative array of attributes, e.g., array(
 282          *   'href' => 'http://www.mediawiki.org/' ).  See expandAttributes() for
 283          *   further documentation.
 284          * @return array An array of attributes functionally identical to $attribs
 285          */
 286         private static function dropDefaults( $element, $attribs ) {
 287
 288                 // Whenever altering this array, please provide a covering test case
 289                 // in HtmlTest::provideElementsWithAttributesHavingDefaultValues
 290                 static $attribDefaults = array(
 291                         'area' => array( 'shape' => 'rect' ),
 292                         'button' => array(
 293                                 'formaction' => 'GET',
 294                                 'formenctype' => 'application/x-www-form-urlencoded',
 295                         ),
 296                         'canvas' => array(
 297                                 'height' => '150',
 298                                 'width' => '300',
 299                         ),
 300                         'command' => array( 'type' => 'command' ),
 301                         'form' => array(
 302                                 'action' => 'GET',
 303                                 'autocomplete' => 'on',
 304                                 'enctype' => 'application/x-www-form-urlencoded',
 305                         ),
 306                         'input' => array(
 307                                 'formaction' => 'GET',
 308                                 'type' => 'text',
 309                         ),
 310                         'keygen' => array( 'keytype' => 'rsa' ),
 311                         'link' => array( 'media' => 'all' ),
 312                         'menu' => array( 'type' => 'list' ),
 313                         // Note: the use of text/javascript here instead of other JavaScript
 314                         // MIME types follows the HTML5 spec.
 315                         'script' => array( 'type' => 'text/javascript' ),
 316                         'style' => array(
 317                                 'media' => 'all',
 318                                 'type' => 'text/css',
 319                         ),
 320                         'textarea' => array( 'wrap' => 'soft' ),
 321                 );
 322
 323                 $element = strtolower( $element );
 324
 325                 foreach ( $attribs as $attrib => $value ) {
 326                         $lcattrib = strtolower( $attrib );
 327                         if ( is_array( $value ) ) {
 328                                 $value = implode( ' ', $value );
 329                         } else {
 330                                 $value = strval( $value );
 331                         }
 332
 333                         // Simple checks using $attribDefaults
 334                         if ( isset( $attribDefaults[$element][$lcattrib] ) &&
 335                         $attribDefaults[$element][$lcattrib] == $value ) {
 336                                 unset( $attribs[$attrib] );
 337                         }
 338
 339                         if ( $lcattrib == 'class' && $value == '' ) {
 340                                 unset( $attribs[$attrib] );
 341                         }
 342                 }
 343
 344                 // More subtle checks
 345                 if ( $element === 'link' && isset( $attribs['type'] )
 346                 && strval( $attribs['type'] ) == 'text/css' ) {
 347                         unset( $attribs['type'] );
 348                 }
 349                 if ( $element === 'input' ) {
 350                         $type = isset( $attribs['type'] ) ? $attribs['type'] : null;
 351                         $value = isset( $attribs['value'] ) ? $attribs['value'] : null;
 352                         if ( $type === 'checkbox' || $type === 'radio' ) {
 353                                 // The default value for checkboxes and radio buttons is 'on'
 354                                 // not ''. By stripping value="" we break radio boxes that
 355                                 // actually wants empty values.
 356                                 if ( $value === 'on' ) {
 357                                         unset( $attribs['value'] );
 358                                 }
 359                         } elseif ( $type === 'submit' ) {
 360                                 // The default value for submit appears to be "Submit" but
 361                                 // let's not bother stripping out localized text that matches
 362                                 // that.
 363                         } else {
 364                                 // The default value for nearly every other field type is ''
 365                                 // The 'range' and 'color' types use different defaults but
 366                                 // stripping a value="" does not hurt them.
 367                                 if ( $value === '' ) {
 368                                         unset( $attribs['value'] );
 369                                 }
 370                         }
 371                 }
 372                 if ( $element === 'select' && isset( $attribs['size'] ) ) {
 373                         if ( in_array( 'multiple', $attribs )
 374                                 || ( isset( $attribs['multiple'] ) && $attribs['multiple'] !== false )
 375                         ) {
 376                                 // A multi-select
 377                                 if ( strval( $attribs['size'] ) == '4' ) {
 378                                         unset( $attribs['size'] );
 379                                 }
 380                         } else {
 381                                 // Single select
 382                                 if ( strval( $attribs['size'] ) == '1' ) {
 383                                         unset( $attribs['size'] );
 384                                 }
 385                         }
 386                 }
 387
 388                 return $attribs;
 389         }
 390
 391         /**
 392          * Given an associative array of element attributes, generate a string
 393          * to stick after the element name in HTML output.  Like array( 'href' =>
 394          * 'http://www.mediawiki.org/' ) becomes something like
 395          * ' href="http://www.mediawiki.org"'.  Again, this is like
 396          * Xml::expandAttributes(), but it implements some HTML-specific logic.
 397          * For instance, it will omit quotation marks if $wgWellFormedXml is false,
 398          * and will treat boolean attributes specially.
 399          *
 400          * Attributes that can contain space-separated lists ('class', 'accesskey' and 'rel') array
 401          * values are allowed as well, which will automagically be normalized
 402          * and converted to a space-separated string. In addition to a numerical
 403          * array, the attribute value may also be an associative array. See the
 404          * example below for how that works.
 405          *
 406          * @par Numerical array
 407          * @code
 408          *     Html::element( 'em', array(
 409          *         'class' => array( 'foo', 'bar' )
 410          *     ) );
 411          *     // gives '<em class="foo bar"></em>'
 412          * @endcode
 413          *
 414          * @par Associative array
 415          * @code
 416          *     Html::element( 'em', array(
 417          *         'class' => array( 'foo', 'bar', 'foo' => false, 'quux' => true )
 418          *     ) );
 419          *     // gives '<em class="bar quux"></em>'
 420          * @endcode
 421          *
 422          * @param array $attribs Associative array of attributes, e.g., array(
 423          *   'href' => 'http://www.mediawiki.org/' ).  Values will be HTML-escaped.
 424          *   A value of false means to omit the attribute.  For boolean attributes,
 425          *   you can omit the key, e.g., array( 'checked' ) instead of
 426          *   array( 'checked' => 'checked' ) or such.
 427          *
 428          * @throws MWException If an attribute that doesn't allow lists is set to an array
 429          * @return string HTML fragment that goes between element name and '>'
 430          *   (starting with a space if at least one attribute is output)
 431          */
 432         public static function expandAttributes( $attribs ) {
 433                 global $wgWellFormedXml;
 434
 435                 $ret = '';
 436                 $attribs = (array)$attribs;
 437                 foreach ( $attribs as $key => $value ) {
 438                         // Support intuitive array( 'checked' => true/false ) form
 439                         if ( $value === false || is_null( $value ) ) {
 440                                 continue;
 441                         }
 442
 443                         // For boolean attributes, support array( 'foo' ) instead of
 444                         // requiring array( 'foo' => 'meaningless' ).
 445                         if ( is_int( $key )
 446                         && in_array( strtolower( $value ), self::$boolAttribs ) ) {
 447                                 $key = $value;
 448                         }
 449
 450                         // Not technically required in HTML5 but we'd like consistency
 451                         // and better compression anyway.
 452                         $key = strtolower( $key );
 453
 454                         // Bug 23769: Blacklist all form validation attributes for now.  Current
 455                         // (June 2010) WebKit has no UI, so the form just refuses to submit
 456                         // without telling the user why, which is much worse than failing
 457                         // server-side validation.  Opera is the only other implementation at
 458                         // this time, and has ugly UI, so just kill the feature entirely until
 459                         // we have at least one good implementation.
 460
 461                         // As the default value of "1" for "step" rejects decimal
 462                         // numbers to be entered in 'type="number"' fields, allow
 463                         // the special case 'step="any"'.
 464
 465                         if ( in_array( $key, array( 'max', 'min', 'pattern', 'required' ) )
 466                                 || $key === 'step' && $value !== 'any' ) {
 467                                 continue;
 468                         }
 469
 470                         // http://www.w3.org/TR/html401/index/attributes.html ("space-separated")
 471                         // http://www.w3.org/TR/html5/index.html#attributes-1 ("space-separated")
 472                         $spaceSeparatedListAttributes = array(
 473                                 'class', // html4, html5
 474                                 'accesskey', // as of html5, multiple space-separated values allowed
 475                                 // html4-spec doesn't document rel= as space-separated
 476                                 // but has been used like that and is now documented as such
 477                                 // in the html5-spec.
 478                                 'rel',
 479                         );
 480
 481                         // Specific features for attributes that allow a list of space-separated values
 482                         if ( in_array( $key, $spaceSeparatedListAttributes ) ) {
 483                                 // Apply some normalization and remove duplicates
 484
 485                                 // Convert into correct array. Array can contain space-separated
 486                                 // values. Implode/explode to get those into the main array as well.
 487                                 if ( is_array( $value ) ) {
 488                                         // If input wasn't an array, we can skip this step
 489                                         $newValue = array();
 490                                         foreach ( $value as $k => $v ) {
 491                                                 if ( is_string( $v ) ) {
 492                                                         // String values should be normal `array( 'foo' )`
 493                                                         // Just append them
 494                                                         if ( !isset( $value[$v] ) ) {
 495                                                                 // As a special case don't set 'foo' if a
 496                                                                 // separate 'foo' => true/false exists in the array
 497                                                                 // keys should be authoritative
 498                                                                 $newValue[] = $v;
 499                                                         }
 500                                                 } elseif ( $v ) {
 501                                                         // If the value is truthy but not a string this is likely
 502                                                         // an array( 'foo' => true ), falsy values don't add strings
 503                                                         $newValue[] = $k;
 504                                                 }
 505                                         }
 506                                         $value = implode( ' ', $newValue );
 507                                 }
 508                                 $value = explode( ' ', $value );
 509
 510                                 // Normalize spacing by fixing up cases where people used
 511                                 // more than 1 space and/or a trailing/leading space
 512                                 $value = array_diff( $value, array( '', ' ' ) );
 513
 514                                 // Remove duplicates and create the string
 515                                 $value = implode( ' ', array_unique( $value ) );
 516                         } elseif ( is_array( $value ) ) {
 517                                 throw new MWException( "HTML attribute $key can not contain a list of values" );
 518                         }
 519
 520                         // See the "Attributes" section in the HTML syntax part of HTML5,
 521                         // 9.1.2.3 as of 2009-08-10.  Most attributes can have quotation
 522                         // marks omitted, but not all.  (Although a literal " is not
 523                         // permitted, we don't check for that, since it will be escaped
 524                         // anyway.)
 525                         #
 526                         // See also research done on further characters that need to be
 527                         // escaped: http://code.google.com/p/html5lib/issues/detail?id=93
 528                         $badChars = "\\x00- '=<>`/\x{00a0}\x{1680}\x{180e}\x{180F}\x{2000}\x{2001}"
 529                                 . "\x{2002}\x{2003}\x{2004}\x{2005}\x{2006}\x{2007}\x{2008}\x{2009}"
 530                                 . "\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}";
 531                         if ( $wgWellFormedXml || $value === ''
 532                         || preg_match( "![$badChars]!u", $value ) ) {
 533                                 $quote = '"';
 534                         } else {
 535                                 $quote = '';
 536                         }
 537
 538                         if ( in_array( $key, self::$boolAttribs ) ) {
 539                                 // In HTML5, we can leave the value empty. If we don't need
 540                                 // well-formed XML, we can omit the = entirely.
 541                                 if ( !$wgWellFormedXml ) {
 542                                         $ret .= " $key";
 543                                 } else {
 544                                         $ret .= " $key=\"\"";
 545                                 }
 546                         } else {
 547                                 // Apparently we need to entity-encode \n, \r, \t, although the
 548                                 // spec doesn't mention that.  Since we're doing strtr() anyway,
 549                                 // and we don't need <> escaped here, we may as well not call
 550                                 // htmlspecialchars().
 551                                 // @todo FIXME: Verify that we actually need to
 552                                 // escape \n\r\t here, and explain why, exactly.
 553                                 #
 554                                 // We could call Sanitizer::encodeAttribute() for this, but we
 555                                 // don't because we're stubborn and like our marginal savings on
 556                                 // byte size from not having to encode unnecessary quotes.
 557                                 $map = array(
 558                                         '&' => '&amp;',
 559                                         '"' => '&quot;',
 560                                         "\n" => '&#10;',
 561                                         "\r" => '&#13;',
 562                                         "\t" => '&#9;'
 563                                 );
 564                                 if ( $wgWellFormedXml ) {
 565                                         // This is allowed per spec: <http://www.w3.org/TR/xml/#NT-AttValue>
 566                                         // But reportedly it breaks some XML tools?
 567                                         // @todo FIXME: Is this really true?
 568                                         $map['<'] = '&lt;';
 569                                 }
 570                                 $ret .= " $key=$quote" . strtr( $value, $map ) . $quote;
 571                         }
 572                 }
 573                 return $ret;
 574         }
 575
 576         /**
 577          * Output a "<script>" tag with the given contents.
 578          *
 579          * @todo do some useful escaping as well, like if $contents contains
 580          * literal "</script>" or (for XML) literal "]]>".
 581          *
 582          * @param string $contents JavaScript
 583          * @return string Raw HTML
 584          */
 585         public static function inlineScript( $contents ) {
 586                 global $wgWellFormedXml;
 587
 588                 $attrs = array();
 589
 590                 if ( $wgWellFormedXml && preg_match( '/[<&]/', $contents ) ) {
 591                         $contents = "/*<![CDATA[*/$contents/*]]>*/";
 592                 }
 593
 594                 return self::rawElement( 'script', $attrs, $contents );
 595         }
 596
 597         /**
 598          * Output a "<script>" tag linking to the given URL, e.g.,
 599          * "<script src=foo.js></script>".
 600          *
 601          * @param string $url
 602          * @return string Raw HTML
 603          */
 604         public static function linkedScript( $url ) {
 605                 $attrs = array( 'src' => $url );
 606
 607                 return self::element( 'script', $attrs );
 608         }
 609
 610         /**
 611          * Output a "<style>" tag with the given contents for the given media type
 612          * (if any).  TODO: do some useful escaping as well, like if $contents
 613          * contains literal "</style>" (admittedly unlikely).
 614          *
 615          * @param string $contents CSS
 616          * @param string $media A media type string, like 'screen'
 617          * @return string Raw HTML
 618          */
 619         public static function inlineStyle( $contents, $media = 'all' ) {
 620                 global $wgWellFormedXml;
 621
 622                 if ( $wgWellFormedXml && preg_match( '/[<&]/', $contents ) ) {
 623                         $contents = "/*<![CDATA[*/$contents/*]]>*/";
 624                 }
 625
 626                 return self::rawElement( 'style', array(
 627                         'type' => 'text/css',
 628                         'media' => $media,
 629                 ), $contents );
 630         }
 631
 632         /**
 633          * Output a "<link rel=stylesheet>" linking to the given URL for the given
 634          * media type (if any).
 635          *
 636          * @param string $url
 637          * @param string $media A media type string, like 'screen'
 638          * @return string Raw HTML
 639          */
 640         public static function linkedStyle( $url, $media = 'all' ) {
 641                 return self::element( 'link', array(
 642                         'rel' => 'stylesheet',
 643                         'href' => $url,
 644                         'type' => 'text/css',
 645                         'media' => $media,
 646                 ) );
 647         }
 648
 649         /**
 650          * Convenience function to produce an "<input>" element.  This supports the
 651          * new HTML5 input types and attributes.
 652          *
 653          * @param string $name Name attribute
 654          * @param array $value Value attribute
 655          * @param string $type Type attribute
 656          * @param array $attribs Associative array of miscellaneous extra
 657          *   attributes, passed to Html::element()
 658          * @return string Raw HTML
 659          */
 660         public static function input( $name, $value = '', $type = 'text', $attribs = array() ) {
 661                 $attribs['type'] = $type;
 662                 $attribs['value'] = $value;
 663                 $attribs['name'] = $name;
 664                 if ( in_array( $type, array( 'text', 'search', 'email', 'password', 'number' ) ) ) {
 665                         $attribs = Html::getTextInputAttributes( $attribs );
 666                 }
 667                 return self::element( 'input', $attribs );
 668         }
 669
 670         /**
 671          * Convenience function to produce a checkbox (input element with type=checkbox)
 672          *
 673          * @param string $name Name attribute
 674          * @param bool $checked Whether the checkbox is checked or not
 675          * @param array $attribs Array of additional attributes
 676          * @return string
 677          */
 678         public static function check( $name, $checked = false, array $attribs = array() ) {
 679                 if ( isset( $attribs['value'] ) ) {
 680                         $value = $attribs['value'];
 681                         unset( $attribs['value'] );
 682                 } else {
 683                         $value = 1;
 684                 }
 685
 686                 if ( $checked ) {
 687                         $attribs[] = 'checked';
 688                 }
 689
 690                 return self::input( $name, $value, 'checkbox', $attribs );
 691         }
 692
 693         /**
 694          * Convenience function to produce a checkbox (input element with type=checkbox)
 695          *
 696          * @param string $name Name attribute
 697          * @param bool $checked Whether the checkbox is checked or not
 698          * @param array $attribs Array of additional attributes
 699          * @return string
 700          */
 701         public static function radio( $name, $checked = false, array $attribs = array() ) {
 702                 if ( isset( $attribs['value'] ) ) {
 703                         $value = $attribs['value'];
 704                         unset( $attribs['value'] );
 705                 } else {
 706                         $value = 1;
 707                 }
 708
 709                 if ( $checked ) {
 710                         $attribs[] = 'checked';
 711                 }
 712
 713                 return self::input( $name, $value, 'radio', $attribs );
 714         }
 715
 716         /**
 717          * Convenience function for generating a label for inputs.
 718          *
 719          * @param string $label Contents of the label
 720          * @param string $id ID of the element being labeled
 721          * @param array $attribs Additional attributes
 722          * @return string
 723          */
 724         public static function label( $label, $id, array $attribs = array() ) {
 725                 $attribs += array(
 726                         'for' => $id
 727                 );
 728                 return self::element( 'label', $attribs, $label );
 729         }
 730
 731         /**
 732          * Convenience function to produce an input element with type=hidden
 733          *
 734          * @param string $name Name attribute
 735          * @param string $value Value attribute
 736          * @param array $attribs Associative array of miscellaneous extra
 737          *   attributes, passed to Html::element()
 738          * @return string Raw HTML
 739          */
 740         public static function hidden( $name, $value, $attribs = array() ) {
 741                 return self::input( $name, $value, 'hidden', $attribs );
 742         }
 743
 744         /**
 745          * Convenience function to produce a <textarea> element.
 746          *
 747          * This supports leaving out the cols= and rows= which Xml requires and are
 748          * required by HTML4/XHTML but not required by HTML5.
 749          *
 750          * @param string $name Name attribute
 751          * @param string $value Value attribute
 752          * @param array $attribs Associative array of miscellaneous extra
 753          *   attributes, passed to Html::element()
 754          * @return string Raw HTML
 755          */
 756         public static function textarea( $name, $value = '', $attribs = array() ) {
 757                 $attribs['name'] = $name;
 758
 759                 if ( substr( $value, 0, 1 ) == "\n" ) {
 760                         // Workaround for bug 12130: browsers eat the initial newline
 761                         // assuming that it's just for show, but they do keep the later
 762                         // newlines, which we may want to preserve during editing.
 763                         // Prepending a single newline
 764                         $spacedValue = "\n" . $value;
 765                 } else {
 766                         $spacedValue = $value;
 767                 }
 768                 return self::element( 'textarea', Html::getTextInputAttributes( $attribs ), $spacedValue );
 769         }
 770
 771         /**
 772          * Build a drop-down box for selecting a namespace
 773          *
 774          * @param array $params Params to set.
 775          * - selected: [optional] Id of namespace which should be pre-selected
 776          * - all: [optional] Value of item for "all namespaces". If null or unset,
 777          *   no "<option>" is generated to select all namespaces.
 778          * - label: text for label to add before the field.
 779          * - exclude: [optional] Array of namespace ids to exclude.
 780          * - disable: [optional] Array of namespace ids for which the option should
 781          *   be disabled in the selector.
 782          * @param array $selectAttribs HTML attributes for the generated select element.
 783          * - id:   [optional], default: 'namespace'.
 784          * - name: [optional], default: 'namespace'.
 785          * @return string HTML code to select a namespace.
 786          */
 787         public static function namespaceSelector( array $params = array(),
 788                 array $selectAttribs = array()
 789         ) {
 790                 global $wgContLang;
 791
 792                 ksort( $selectAttribs );
 793
 794                 // Is a namespace selected?
 795                 if ( isset( $params['selected'] ) ) {
 796                         // If string only contains digits, convert to clean int. Selected could also
 797                         // be "all" or "" etc. which needs to be left untouched.
 798                         // PHP is_numeric() has issues with large strings, PHP ctype_digit has other issues
 799                         // and returns false for already clean ints. Use regex instead..
 800                         if ( preg_match( '/^\d+$/', $params['selected'] ) ) {
 801                                 $params['selected'] = intval( $params['selected'] );
 802                         }
 803                         // else: leaves it untouched for later processing
 804                 } else {
 805                         $params['selected'] = '';
 806                 }
 807
 808                 if ( !isset( $params['exclude'] ) || !is_array( $params['exclude'] ) ) {
 809                         $params['exclude'] = array();
 810                 }
 811                 if ( !isset( $params['disable'] ) || !is_array( $params['disable'] ) ) {
 812                         $params['disable'] = array();
 813                 }
 814
 815                 // Associative array between option-values and option-labels
 816                 $options = array();
 817
 818                 if ( isset( $params['all'] ) ) {
 819                         // add an option that would let the user select all namespaces.
 820                         // Value is provided by user, the name shown is localized for the user.
 821                         $options[$params['all']] = wfMessage( 'namespacesall' )->text();
 822                 }
 823                 // Add all namespaces as options (in the content language)
 824                 $options += $wgContLang->getFormattedNamespaces();
 825
 826                 // Convert $options to HTML and filter out namespaces below 0
 827                 $optionsHtml = array();
 828                 foreach ( $options as $nsId => $nsName ) {
 829                         if ( $nsId < NS_MAIN || in_array( $nsId, $params['exclude'] ) ) {
 830                                 continue;
 831                         }
 832                         if ( $nsId === NS_MAIN ) {
 833                                 // For other namespaces use use the namespace prefix as label, but for
 834                                 // main we don't use "" but the user message describing it (e.g. "(Main)" or "(Article)")
 835                                 $nsName = wfMessage( 'blanknamespace' )->text();
 836                         } elseif ( is_int( $nsId ) ) {
 837                                 $nsName = $wgContLang->convertNamespace( $nsId );
 838                         }
 839                         $optionsHtml[] = Html::element(
 840                                 'option', array(
 841                                         'disabled' => in_array( $nsId, $params['disable'] ),
 842                                         'value' => $nsId,
 843                                         'selected' => $nsId === $params['selected'],
 844                                 ), $nsName
 845                         );
 846                 }
 847
 848                 if ( !array_key_exists( 'id', $selectAttribs ) ) {
 849                         $selectAttribs['id'] = 'namespace';
 850                 }
 851
 852                 if ( !array_key_exists( 'name', $selectAttribs ) ) {
 853                         $selectAttribs['name'] = 'namespace';
 854                 }
 855
 856                 $ret = '';
 857                 if ( isset( $params['label'] ) ) {
 858                         $ret .= Html::element(
 859                                 'label', array(
 860                                         'for' => isset( $selectAttribs['id'] ) ? $selectAttribs['id'] : null,
 861                                 ), $params['label']
 862                         ) . '&#160;';
 863                 }
 864
 865                 // Wrap options in a <select>
 866                 $ret .= Html::openElement( 'select', $selectAttribs )
 867                         . "\n"
 868                         . implode( "\n", $optionsHtml )
 869                         . "\n"
 870                         . Html::closeElement( 'select' );
 871
 872                 return $ret;
 873         }
 874
 875         /**
 876          * Constructs the opening html-tag with necessary doctypes depending on
 877          * global variables.
 878          *
 879          * @param array $attribs Associative array of miscellaneous extra
 880          *   attributes, passed to Html::element() of html tag.
 881          * @return string Raw HTML
 882          */
 883         public static function htmlHeader( $attribs = array() ) {
 884                 $ret = '';
 885
 886                 global $wgHtml5Version, $wgMimeType, $wgXhtmlNamespaces;
 887
 888                 $isXHTML = self::isXmlMimeType( $wgMimeType );
 889
 890                 if ( $isXHTML ) { // XHTML5
 891                         // XML MIME-typed markup should have an xml header.
 892                         // However a DOCTYPE is not needed.
 893                         $ret .= "<?xml version=\"1.0\" encoding=\"UTF-8\" ?" . ">\n";
 894
 895                         // Add the standard xmlns
 896                         $attribs['xmlns'] = 'http://www.w3.org/1999/xhtml';
 897
 898                         // And support custom namespaces
 899                         foreach ( $wgXhtmlNamespaces as $tag => $ns ) {
 900                                 $attribs["xmlns:$tag"] = $ns;
 901                         }
 902                 } else { // HTML5
 903                         // DOCTYPE
 904                         $ret .= "<!DOCTYPE html>\n";
 905                 }
 906
 907                 if ( $wgHtml5Version ) {
 908                         $attribs['version'] = $wgHtml5Version;
 909                 }
 910
 911                 $html = Html::openElement( 'html', $attribs );
 912
 913                 if ( $html ) {
 914                         $html .= "\n";
 915                 }
 916
 917                 $ret .= $html;
 918
 919                 return $ret;
 920         }
 921
 922         /**
 923          * Determines if the given MIME type is xml.
 924          *
 925          * @param string $mimetype MIME type
 926          * @return bool
 927          */
 928         public static function isXmlMimeType( $mimetype ) {
 929                 # http://www.whatwg.org/html/infrastructure.html#xml-mime-type
 930                 # * text/xml
 931                 # * application/xml
 932                 # * Any MIME type with a subtype ending in +xml (this implicitly includes application/xhtml+xml)
 933                 return (bool)preg_match( '!^(text|application)/xml$|^.+/.+\+xml$!', $mimetype );
 934         }
 935
 936         /**
 937          * Get HTML for an info box with an icon.
 938          *
 939          * @param string $text Wikitext, get this with wfMessage()->plain()
 940          * @param string $icon Path to icon file (used as 'src' attribute)
 941          * @param string $alt Alternate text for the icon
 942          * @param string $class Additional class name to add to the wrapper div
 943          *
 944          * @return string
 945          */
 946         static function infoBox( $text, $icon, $alt, $class = false ) {
 947                 $s = Html::openElement( 'div', array( 'class' => "mw-infobox $class" ) );
 948
 949                 $s .= Html::openElement( 'div', array( 'class' => 'mw-infobox-left' ) ) .
 950                                 Html::element( 'img',
 951                                         array(
 952                                                 'src' => $icon,
 953                                                 'alt' => $alt,
 954                                         )
 955                                 ) .
 956                                 Html::closeElement( 'div' );
 957
 958                 $s .= Html::openElement( 'div', array( 'class' => 'mw-infobox-right' ) ) .
 959                                 $text .
 960                                 Html::closeElement( 'div' );
 961                 $s .= Html::element( 'div', array( 'style' => 'clear: left;' ), ' ' );
 962
 963                 $s .= Html::closeElement( 'div' );
 964
 965                 $s .= Html::element( 'div', array( 'style' => 'clear: left;' ), ' ' );
 966
 967                 return $s;
 968         }
 969
 970         /**
 971          * Generate a srcset attribute value from an array mapping pixel densities
 972          * to URLs. Note that srcset supports width and height values as well, which
 973          * are not used here.
 974          *
 975          * @param array $urls
 976          * @return string
 977          */
 978         static function srcSet( $urls ) {
 979                 $candidates = array();
 980                 foreach ( $urls as $density => $url ) {
 981                         // Image candidate syntax per current whatwg live spec, 2012-09-23:
 982                         // http://www.whatwg.org/html/embedded-content-1.html#attr-img-srcset
 983                         $candidates[] = "{$url} {$density}x";
 984                 }
 985                 return implode( ", ", $candidates );
 986         }
 987 }