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 button elements
 106          * and apply a set of default attributes when $wgUseMediaWikiUIEverywhere enabled.
 107          * @param array $modifiers to add to the button
 108          * @see https://tools.wmflabs.org/styleguide/desktop/index.html for guidance on available modifiers
 109          * @return array $attrs A modified attribute array
 110          */
 111         public static function buttonAttributes( $attrs, $modifiers = array() ) {
 112                 global $wgUseMediaWikiUIEverywhere;
 113                 if ( $wgUseMediaWikiUIEverywhere ) {
 114                         if ( isset( $attrs['class'] ) ) {
 115                                 if ( is_array( $attrs['class'] ) ) {
 116                                         $attrs['class'][] = 'mw-ui-button';
 117                                         $attrs = array_merge( $attrs, $modifiers );
 118                                         // ensure compatibility with Xml
 119                                         $attrs['class'] = implode( ' ', $attrs['class'] );
 120                                 } else {
 121                                         $attrs['class'] .= ' mw-ui-button ' . implode( ' ', $modifiers );
 122                                 }
 123                         } else {
 124                                 $attrs['class'] = array( 'mw-ui-button' );
 125                                 // ensure compatibility with Xml
 126                                 $attrs['class'] = implode( ' ', array_merge( $attrs['class'], $modifiers ) );
 127                         }
 128                 }
 129                 return $attrs;
 130         }
 131
 132         /**
 133          * Modifies a set of attributes meant for text input elements
 134          * and apply a set of default attributes.
 135          * Removes size attribute when $wgUseMediaWikiUIEverywhere enabled.
 136          * @param array $attrs An attribute array.
 137          * @return array $attrs A modified attribute array
 138          */
 139         public static function getTextInputAttributes( $attrs ) {
 140                 global $wgUseMediaWikiUIEverywhere;
 141                 if ( !$attrs ) {
 142                         $attrs = array();
 143                 }
 144                 if ( isset( $attrs['class'] ) ) {
 145                         if ( is_array( $attrs['class'] ) ) {
 146                                 $attrs['class'][] = 'mw-ui-input';
 147                         } else {
 148                                 $attrs['class'] .= ' mw-ui-input';
 149                         }
 150                 } else {
 151                         $attrs['class'] = 'mw-ui-input';
 152                 }
 153                 if ( $wgUseMediaWikiUIEverywhere ) {
 154                         // Note that size can effect the desired width rendering of mw-ui-input elements
 155                         // so it is removed. Left intact when mediawiki ui not enabled.
 156                         unset( $attrs['size'] );
 157                 }
 158                 return $attrs;
 159         }
 160
 161         /**
 162          * Returns an HTML link element in a string styled as a button
 163          * (when $wgUseMediaWikiUIEverywhere is enabled).
 164          *
 165          * @param string $contents The raw HTML contents of the element: *not*
 166          *   escaped!
 167          * @param array $attrs Associative array of attributes, e.g., array(
 168          *   'href' => 'http://www.mediawiki.org/' ). See expandAttributes() for
 169          *   further documentation.
 170          * @param array $modifiers to add to the button
 171          * @see http://tools.wmflabs.org/styleguide/desktop/index.html for guidance on available modifiers
 172          * @return string Raw HTML
 173          */
 174         public static function linkButton( $contents, $attrs, $modifiers = array() ) {
 175                 return Html::element( 'a',
 176                         self::buttonAttributes( $attrs, $modifiers ),
 177                         $contents
 178                 );
 179         }
 180
 181         /**
 182          * Returns an HTML link element in a string styled as a button
 183          * (when $wgUseMediaWikiUIEverywhere is enabled).
 184          *
 185          * @param string $contents The raw HTML contents of the element: *not*
 186          *   escaped!
 187          * @param array $attrs Associative array of attributes, e.g., array(
 188          *   'href' => 'http://www.mediawiki.org/' ). See expandAttributes() for
 189          *   further documentation.
 190          * @param array $modifiers to add to the button
 191          * @see http://tools.wmflabs.org/styleguide/desktop/index.html for guidance on available modifiers
 192          * @return string Raw HTML
 193          */
 194         public static function submitButton( $contents, $attrs, $modifiers = array() ) {
 195                 $attrs['type'] = 'submit';
 196                 $attrs['value'] = $contents;
 197                 return Html::element( 'input', self::buttonAttributes( $attrs, $modifiers ) );
 198         }
 199
 200         /**
 201          * Returns an HTML element in a string.  The major advantage here over
 202          * manually typing out the HTML is that it will escape all attribute
 203          * values.
 204          *
 205          * This is quite similar to Xml::tags(), but it implements some useful
 206          * HTML-specific logic.  For instance, there is no $allowShortTag
 207          * parameter: the closing tag is magically omitted if $element has an empty
 208          * content model.  If $wgWellFormedXml is false, then a few bytes will be
 209          * shaved off the HTML output as well.
 210          *
 211          * @param string $element The element's name, e.g., 'a'
 212          * @param array $attribs Associative array of attributes, e.g., array(
 213          *   'href' => 'http://www.mediawiki.org/' ). See expandAttributes() for
 214          *   further documentation.
 215          * @param string $contents The raw HTML contents of the element: *not*
 216          *   escaped!
 217          * @return string Raw HTML
 218          */
 219         public static function rawElement( $element, $attribs = array(), $contents = '' ) {
 220                 global $wgWellFormedXml;
 221                 $start = self::openElement( $element, $attribs );
 222                 if ( in_array( $element, self::$voidElements ) ) {
 223                         if ( $wgWellFormedXml ) {
 224                                 // Silly XML.
 225                                 return substr( $start, 0, -1 ) . ' />';
 226                         }
 227                         return $start;
 228                 } else {
 229                         return "$start$contents" . self::closeElement( $element );
 230                 }
 231         }
 232
 233         /**
 234          * Identical to rawElement(), but HTML-escapes $contents (like
 235          * Xml::element()).
 236          *
 237          * @param string $element
 238          * @param array $attribs
 239          * @param string $contents
 240          *
 241          * @return string
 242          */
 243         public static function element( $element, $attribs = array(), $contents = '' ) {
 244                 return self::rawElement( $element, $attribs, strtr( $contents, array(
 245                         // There's no point in escaping quotes, >, etc. in the contents of
 246                         // elements.
 247                         '&' => '&amp;',
 248                         '<' => '&lt;'
 249                 ) ) );
 250         }
 251
 252         /**
 253          * Identical to rawElement(), but has no third parameter and omits the end
 254          * tag (and the self-closing '/' in XML mode for empty elements).
 255          *
 256          * @param string $element
 257          * @param array $attribs
 258          *
 259          * @return string
 260          */
 261         public static function openElement( $element, $attribs = array() ) {
 262                 $attribs = (array)$attribs;
 263                 // This is not required in HTML5, but let's do it anyway, for
 264                 // consistency and better compression.
 265                 $element = strtolower( $element );
 266
 267                 // Remove invalid input types
 268                 if ( $element == 'input' ) {
 269                         $validTypes = array(
 270                                 'hidden',
 271                                 'text',
 272                                 'password',
 273                                 'checkbox',
 274                                 'radio',
 275                                 'file',
 276                                 'submit',
 277                                 'image',
 278                                 'reset',
 279                                 'button',
 280
 281                                 // HTML input types
 282                                 'datetime',
 283                                 'datetime-local',
 284                                 'date',
 285                                 'month',
 286                                 'time',
 287                                 'week',
 288                                 'number',
 289                                 'range',
 290                                 'email',
 291                                 'url',
 292                                 'search',
 293                                 'tel',
 294                                 'color',
 295                         );
 296                         if ( isset( $attribs['type'] ) && !in_array( $attribs['type'], $validTypes ) ) {
 297                                 unset( $attribs['type'] );
 298                         }
 299                 }
 300
 301                 // According to standard the default type for <button> elements is "submit".
 302                 // Depending on compatibility mode IE might use "button", instead.
 303                 // We enforce the standard "submit".
 304                 if ( $element == 'button' && !isset( $attribs['type'] ) ) {
 305                         $attribs['type'] = 'submit';
 306                 }
 307
 308                 return "<$element" . self::expandAttributes(
 309                         self::dropDefaults( $element, $attribs ) ) . '>';
 310         }
 311
 312         /**
 313          * Returns "</$element>"
 314          *
 315          * @since 1.17
 316          * @param string $element Name of the element, e.g., 'a'
 317          * @return string A closing tag
 318          */
 319         public static function closeElement( $element ) {
 320                 $element = strtolower( $element );
 321
 322                 return "</$element>";
 323         }
 324
 325         /**
 326          * Given an element name and an associative array of element attributes,
 327          * return an array that is functionally identical to the input array, but
 328          * possibly smaller.  In particular, attributes might be stripped if they
 329          * are given their default values.
 330          *
 331          * This method is not guaranteed to remove all redundant attributes, only
 332          * some common ones and some others selected arbitrarily at random.  It
 333          * only guarantees that the output array should be functionally identical
 334          * to the input array (currently per the HTML 5 draft as of 2009-09-06).
 335          *
 336          * @param string $element Name of the element, e.g., 'a'
 337          * @param array $attribs Associative array of attributes, e.g., array(
 338          *   'href' => 'http://www.mediawiki.org/' ).  See expandAttributes() for
 339          *   further documentation.
 340          * @return array An array of attributes functionally identical to $attribs
 341          */
 342         private static function dropDefaults( $element, $attribs ) {
 343
 344                 // Whenever altering this array, please provide a covering test case
 345                 // in HtmlTest::provideElementsWithAttributesHavingDefaultValues
 346                 static $attribDefaults = array(
 347                         'area' => array( 'shape' => 'rect' ),
 348                         'button' => array(
 349                                 'formaction' => 'GET',
 350                                 'formenctype' => 'application/x-www-form-urlencoded',
 351                         ),
 352                         'canvas' => array(
 353                                 'height' => '150',
 354                                 'width' => '300',
 355                         ),
 356                         'command' => array( 'type' => 'command' ),
 357                         'form' => array(
 358                                 'action' => 'GET',
 359                                 'autocomplete' => 'on',
 360                                 'enctype' => 'application/x-www-form-urlencoded',
 361                         ),
 362                         'input' => array(
 363                                 'formaction' => 'GET',
 364                                 'type' => 'text',
 365                         ),
 366                         'keygen' => array( 'keytype' => 'rsa' ),
 367                         'link' => array( 'media' => 'all' ),
 368                         'menu' => array( 'type' => 'list' ),
 369                         // Note: the use of text/javascript here instead of other JavaScript
 370                         // MIME types follows the HTML5 spec.
 371                         'script' => array( 'type' => 'text/javascript' ),
 372                         'style' => array(
 373                                 'media' => 'all',
 374                                 'type' => 'text/css',
 375                         ),
 376                         'textarea' => array( 'wrap' => 'soft' ),
 377                 );
 378
 379                 $element = strtolower( $element );
 380
 381                 foreach ( $attribs as $attrib => $value ) {
 382                         $lcattrib = strtolower( $attrib );
 383                         if ( is_array( $value ) ) {
 384                                 $value = implode( ' ', $value );
 385                         } else {
 386                                 $value = strval( $value );
 387                         }
 388
 389                         // Simple checks using $attribDefaults
 390                         if ( isset( $attribDefaults[$element][$lcattrib] )
 391                                 && $attribDefaults[$element][$lcattrib] == $value
 392                         ) {
 393                                 unset( $attribs[$attrib] );
 394                         }
 395
 396                         if ( $lcattrib == 'class' && $value == '' ) {
 397                                 unset( $attribs[$attrib] );
 398                         }
 399                 }
 400
 401                 // More subtle checks
 402                 if ( $element === 'link'
 403                         && isset( $attribs['type'] ) && strval( $attribs['type'] ) == 'text/css'
 404                 ) {
 405                         unset( $attribs['type'] );
 406                 }
 407                 if ( $element === 'input' ) {
 408                         $type = isset( $attribs['type'] ) ? $attribs['type'] : null;
 409                         $value = isset( $attribs['value'] ) ? $attribs['value'] : null;
 410                         if ( $type === 'checkbox' || $type === 'radio' ) {
 411                                 // The default value for checkboxes and radio buttons is 'on'
 412                                 // not ''. By stripping value="" we break radio boxes that
 413                                 // actually wants empty values.
 414                                 if ( $value === 'on' ) {
 415                                         unset( $attribs['value'] );
 416                                 }
 417                         } elseif ( $type === 'submit' ) {
 418                                 // The default value for submit appears to be "Submit" but
 419                                 // let's not bother stripping out localized text that matches
 420                                 // that.
 421                         } else {
 422                                 // The default value for nearly every other field type is ''
 423                                 // The 'range' and 'color' types use different defaults but
 424                                 // stripping a value="" does not hurt them.
 425                                 if ( $value === '' ) {
 426                                         unset( $attribs['value'] );
 427                                 }
 428                         }
 429                 }
 430                 if ( $element === 'select' && isset( $attribs['size'] ) ) {
 431                         if ( in_array( 'multiple', $attribs )
 432                                 || ( isset( $attribs['multiple'] ) && $attribs['multiple'] !== false )
 433                         ) {
 434                                 // A multi-select
 435                                 if ( strval( $attribs['size'] ) == '4' ) {
 436                                         unset( $attribs['size'] );
 437                                 }
 438                         } else {
 439                                 // Single select
 440                                 if ( strval( $attribs['size'] ) == '1' ) {
 441                                         unset( $attribs['size'] );
 442                                 }
 443                         }
 444                 }
 445
 446                 return $attribs;
 447         }
 448
 449         /**
 450          * Given an associative array of element attributes, generate a string
 451          * to stick after the element name in HTML output.  Like array( 'href' =>
 452          * 'http://www.mediawiki.org/' ) becomes something like
 453          * ' href="http://www.mediawiki.org"'.  Again, this is like
 454          * Xml::expandAttributes(), but it implements some HTML-specific logic.
 455          * For instance, it will omit quotation marks if $wgWellFormedXml is false,
 456          * and will treat boolean attributes specially.
 457          *
 458          * Attributes that can contain space-separated lists ('class', 'accesskey' and 'rel') array
 459          * values are allowed as well, which will automagically be normalized
 460          * and converted to a space-separated string. In addition to a numerical
 461          * array, the attribute value may also be an associative array. See the
 462          * example below for how that works.
 463          *
 464          * @par Numerical array
 465          * @code
 466          *     Html::element( 'em', array(
 467          *         'class' => array( 'foo', 'bar' )
 468          *     ) );
 469          *     // gives '<em class="foo bar"></em>'
 470          * @endcode
 471          *
 472          * @par Associative array
 473          * @code
 474          *     Html::element( 'em', array(
 475          *         'class' => array( 'foo', 'bar', 'foo' => false, 'quux' => true )
 476          *     ) );
 477          *     // gives '<em class="bar quux"></em>'
 478          * @endcode
 479          *
 480          * @param array $attribs Associative array of attributes, e.g., array(
 481          *   'href' => 'http://www.mediawiki.org/' ).  Values will be HTML-escaped.
 482          *   A value of false means to omit the attribute.  For boolean attributes,
 483          *   you can omit the key, e.g., array( 'checked' ) instead of
 484          *   array( 'checked' => 'checked' ) or such.
 485          *
 486          * @throws MWException If an attribute that doesn't allow lists is set to an array
 487          * @return string HTML fragment that goes between element name and '>'
 488          *   (starting with a space if at least one attribute is output)
 489          */
 490         public static function expandAttributes( $attribs ) {
 491                 global $wgWellFormedXml;
 492
 493                 $ret = '';
 494                 $attribs = (array)$attribs;
 495                 foreach ( $attribs as $key => $value ) {
 496                         // Support intuitive array( 'checked' => true/false ) form
 497                         if ( $value === false || is_null( $value ) ) {
 498                                 continue;
 499                         }
 500
 501                         // For boolean attributes, support array( 'foo' ) instead of
 502                         // requiring array( 'foo' => 'meaningless' ).
 503                         if ( is_int( $key ) && in_array( strtolower( $value ), self::$boolAttribs ) ) {
 504                                 $key = $value;
 505                         }
 506
 507                         // Not technically required in HTML5 but we'd like consistency
 508                         // and better compression anyway.
 509                         $key = strtolower( $key );
 510
 511                         // Bug 23769: Blacklist all form validation attributes for now.  Current
 512                         // (June 2010) WebKit has no UI, so the form just refuses to submit
 513                         // without telling the user why, which is much worse than failing
 514                         // server-side validation.  Opera is the only other implementation at
 515                         // this time, and has ugly UI, so just kill the feature entirely until
 516                         // we have at least one good implementation.
 517
 518                         // As the default value of "1" for "step" rejects decimal
 519                         // numbers to be entered in 'type="number"' fields, allow
 520                         // the special case 'step="any"'.
 521
 522                         if ( in_array( $key, array( 'max', 'min', 'pattern', 'required' ) )
 523                                 || $key === 'step' && $value !== 'any' ) {
 524                                 continue;
 525                         }
 526
 527                         // http://www.w3.org/TR/html401/index/attributes.html ("space-separated")
 528                         // http://www.w3.org/TR/html5/index.html#attributes-1 ("space-separated")
 529                         $spaceSeparatedListAttributes = array(
 530                                 'class', // html4, html5
 531                                 'accesskey', // as of html5, multiple space-separated values allowed
 532                                 // html4-spec doesn't document rel= as space-separated
 533                                 // but has been used like that and is now documented as such
 534                                 // in the html5-spec.
 535                                 'rel',
 536                         );
 537
 538                         // Specific features for attributes that allow a list of space-separated values
 539                         if ( in_array( $key, $spaceSeparatedListAttributes ) ) {
 540                                 // Apply some normalization and remove duplicates
 541
 542                                 // Convert into correct array. Array can contain space-separated
 543                                 // values. Implode/explode to get those into the main array as well.
 544                                 if ( is_array( $value ) ) {
 545                                         // If input wasn't an array, we can skip this step
 546                                         $newValue = array();
 547                                         foreach ( $value as $k => $v ) {
 548                                                 if ( is_string( $v ) ) {
 549                                                         // String values should be normal `array( 'foo' )`
 550                                                         // Just append them
 551                                                         if ( !isset( $value[$v] ) ) {
 552                                                                 // As a special case don't set 'foo' if a
 553                                                                 // separate 'foo' => true/false exists in the array
 554                                                                 // keys should be authoritative
 555                                                                 $newValue[] = $v;
 556                                                         }
 557                                                 } elseif ( $v ) {
 558                                                         // If the value is truthy but not a string this is likely
 559                                                         // an array( 'foo' => true ), falsy values don't add strings
 560                                                         $newValue[] = $k;
 561                                                 }
 562                                         }
 563                                         $value = implode( ' ', $newValue );
 564                                 }
 565                                 $value = explode( ' ', $value );
 566
 567                                 // Normalize spacing by fixing up cases where people used
 568                                 // more than 1 space and/or a trailing/leading space
 569                                 $value = array_diff( $value, array( '', ' ' ) );
 570
 571                                 // Remove duplicates and create the string
 572                                 $value = implode( ' ', array_unique( $value ) );
 573                         } elseif ( is_array( $value ) ) {
 574                                 throw new MWException( "HTML attribute $key can not contain a list of values" );
 575                         }
 576
 577                         // See the "Attributes" section in the HTML syntax part of HTML5,
 578                         // 9.1.2.3 as of 2009-08-10.  Most attributes can have quotation
 579                         // marks omitted, but not all.  (Although a literal " is not
 580                         // permitted, we don't check for that, since it will be escaped
 581                         // anyway.)
 582
 583                         // See also research done on further characters that need to be
 584                         // escaped: http://code.google.com/p/html5lib/issues/detail?id=93
 585                         $badChars = "\\x00- '=<>`/\x{00a0}\x{1680}\x{180e}\x{180F}\x{2000}\x{2001}"
 586                                 . "\x{2002}\x{2003}\x{2004}\x{2005}\x{2006}\x{2007}\x{2008}\x{2009}"
 587                                 . "\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}";
 588                         if ( $wgWellFormedXml || $value === '' || preg_match( "![$badChars]!u", $value ) ) {
 589                                 $quote = '"';
 590                         } else {
 591                                 $quote = '';
 592                         }
 593
 594                         if ( in_array( $key, self::$boolAttribs ) ) {
 595                                 // In HTML5, we can leave the value empty. If we don't need
 596                                 // well-formed XML, we can omit the = entirely.
 597                                 if ( !$wgWellFormedXml ) {
 598                                         $ret .= " $key";
 599                                 } else {
 600                                         $ret .= " $key=\"\"";
 601                                 }
 602                         } else {
 603                                 // Apparently we need to entity-encode \n, \r, \t, although the
 604                                 // spec doesn't mention that.  Since we're doing strtr() anyway,
 605                                 // and we don't need <> escaped here, we may as well not call
 606                                 // htmlspecialchars().
 607                                 // @todo FIXME: Verify that we actually need to
 608                                 // escape \n\r\t here, and explain why, exactly.
 609                                 #
 610                                 // We could call Sanitizer::encodeAttribute() for this, but we
 611                                 // don't because we're stubborn and like our marginal savings on
 612                                 // byte size from not having to encode unnecessary quotes.
 613                                 $map = array(
 614                                         '&' => '&amp;',
 615                                         '"' => '&quot;',
 616                                         "\n" => '&#10;',
 617                                         "\r" => '&#13;',
 618                                         "\t" => '&#9;'
 619                                 );
 620                                 if ( $wgWellFormedXml ) {
 621                                         // This is allowed per spec: <http://www.w3.org/TR/xml/#NT-AttValue>
 622                                         // But reportedly it breaks some XML tools?
 623                                         // @todo FIXME: Is this really true?
 624                                         $map['<'] = '&lt;';
 625                                 }
 626                                 $ret .= " $key=$quote" . strtr( $value, $map ) . $quote;
 627                         }
 628                 }
 629                 return $ret;
 630         }
 631
 632         /**
 633          * Output a "<script>" tag with the given contents.
 634          *
 635          * @todo do some useful escaping as well, like if $contents contains
 636          * literal "</script>" or (for XML) literal "]]>".
 637          *
 638          * @param string $contents JavaScript
 639          * @return string Raw HTML
 640          */
 641         public static function inlineScript( $contents ) {
 642                 global $wgWellFormedXml;
 643
 644                 $attrs = array();
 645
 646                 if ( $wgWellFormedXml && preg_match( '/[<&]/', $contents ) ) {
 647                         $contents = "/*<![CDATA[*/$contents/*]]>*/";
 648                 }
 649
 650                 return self::rawElement( 'script', $attrs, $contents );
 651         }
 652
 653         /**
 654          * Output a "<script>" tag linking to the given URL, e.g.,
 655          * "<script src=foo.js></script>".
 656          *
 657          * @param string $url
 658          * @return string Raw HTML
 659          */
 660         public static function linkedScript( $url ) {
 661                 $attrs = array( 'src' => $url );
 662
 663                 return self::element( 'script', $attrs );
 664         }
 665
 666         /**
 667          * Output a "<style>" tag with the given contents for the given media type
 668          * (if any).  TODO: do some useful escaping as well, like if $contents
 669          * contains literal "</style>" (admittedly unlikely).
 670          *
 671          * @param string $contents CSS
 672          * @param string $media A media type string, like 'screen'
 673          * @return string Raw HTML
 674          */
 675         public static function inlineStyle( $contents, $media = 'all' ) {
 676                 global $wgWellFormedXml;
 677
 678                 if ( $wgWellFormedXml && preg_match( '/[<&]/', $contents ) ) {
 679                         $contents = "/*<![CDATA[*/$contents/*]]>*/";
 680                 }
 681
 682                 return self::rawElement( 'style', array(
 683                         'type' => 'text/css',
 684                         'media' => $media,
 685                 ), $contents );
 686         }
 687
 688         /**
 689          * Output a "<link rel=stylesheet>" linking to the given URL for the given
 690          * media type (if any).
 691          *
 692          * @param string $url
 693          * @param string $media A media type string, like 'screen'
 694          * @return string Raw HTML
 695          */
 696         public static function linkedStyle( $url, $media = 'all' ) {
 697                 return self::element( 'link', array(
 698                         'rel' => 'stylesheet',
 699                         'href' => $url,
 700                         'type' => 'text/css',
 701                         'media' => $media,
 702                 ) );
 703         }
 704
 705         /**
 706          * Convenience function to produce an "<input>" element.  This supports the
 707          * new HTML5 input types and attributes.
 708          *
 709          * @param string $name Name attribute
 710          * @param array $value Value attribute
 711          * @param string $type Type attribute
 712          * @param array $attribs Associative array of miscellaneous extra
 713          *   attributes, passed to Html::element()
 714          * @return string Raw HTML
 715          */
 716         public static function input( $name, $value = '', $type = 'text', $attribs = array() ) {
 717                 $attribs['type'] = $type;
 718                 $attribs['value'] = $value;
 719                 $attribs['name'] = $name;
 720                 if ( in_array( $type, array( 'text', 'search', 'email', 'password', 'number' ) ) ) {
 721                         $attribs = Html::getTextInputAttributes( $attribs );
 722                 }
 723                 return self::element( 'input', $attribs );
 724         }
 725
 726         /**
 727          * Convenience function to produce a checkbox (input element with type=checkbox)
 728          *
 729          * @param string $name Name attribute
 730          * @param bool $checked Whether the checkbox is checked or not
 731          * @param array $attribs Array of additional attributes
 732          * @return string
 733          */
 734         public static function check( $name, $checked = false, array $attribs = array() ) {
 735                 if ( isset( $attribs['value'] ) ) {
 736                         $value = $attribs['value'];
 737                         unset( $attribs['value'] );
 738                 } else {
 739                         $value = 1;
 740                 }
 741
 742                 if ( $checked ) {
 743                         $attribs[] = 'checked';
 744                 }
 745
 746                 return self::input( $name, $value, 'checkbox', $attribs );
 747         }
 748
 749         /**
 750          * Convenience function to produce a checkbox (input element with type=checkbox)
 751          *
 752          * @param string $name Name attribute
 753          * @param bool $checked Whether the checkbox is checked or not
 754          * @param array $attribs Array of additional attributes
 755          * @return string
 756          */
 757         public static function radio( $name, $checked = false, array $attribs = array() ) {
 758                 if ( isset( $attribs['value'] ) ) {
 759                         $value = $attribs['value'];
 760                         unset( $attribs['value'] );
 761                 } else {
 762                         $value = 1;
 763                 }
 764
 765                 if ( $checked ) {
 766                         $attribs[] = 'checked';
 767                 }
 768
 769                 return self::input( $name, $value, 'radio', $attribs );
 770         }
 771
 772         /**
 773          * Convenience function for generating a label for inputs.
 774          *
 775          * @param string $label Contents of the label
 776          * @param string $id ID of the element being labeled
 777          * @param array $attribs Additional attributes
 778          * @return string
 779          */
 780         public static function label( $label, $id, array $attribs = array() ) {
 781                 $attribs += array(
 782                         'for' => $id
 783                 );
 784                 return self::element( 'label', $attribs, $label );
 785         }
 786
 787         /**
 788          * Convenience function to produce an input element with type=hidden
 789          *
 790          * @param string $name Name attribute
 791          * @param string $value Value attribute
 792          * @param array $attribs Associative array of miscellaneous extra
 793          *   attributes, passed to Html::element()
 794          * @return string Raw HTML
 795          */
 796         public static function hidden( $name, $value, $attribs = array() ) {
 797                 return self::input( $name, $value, 'hidden', $attribs );
 798         }
 799
 800         /**
 801          * Convenience function to produce a <textarea> element.
 802          *
 803          * This supports leaving out the cols= and rows= which Xml requires and are
 804          * required by HTML4/XHTML but not required by HTML5.
 805          *
 806          * @param string $name Name attribute
 807          * @param string $value Value attribute
 808          * @param array $attribs Associative array of miscellaneous extra
 809          *   attributes, passed to Html::element()
 810          * @return string Raw HTML
 811          */
 812         public static function textarea( $name, $value = '', $attribs = array() ) {
 813                 $attribs['name'] = $name;
 814
 815                 if ( substr( $value, 0, 1 ) == "\n" ) {
 816                         // Workaround for bug 12130: browsers eat the initial newline
 817                         // assuming that it's just for show, but they do keep the later
 818                         // newlines, which we may want to preserve during editing.
 819                         // Prepending a single newline
 820                         $spacedValue = "\n" . $value;
 821                 } else {
 822                         $spacedValue = $value;
 823                 }
 824                 return self::element( 'textarea', Html::getTextInputAttributes( $attribs ), $spacedValue );
 825         }
 826
 827         /**
 828          * Build a drop-down box for selecting a namespace
 829          *
 830          * @param array $params Params to set.
 831          * - selected: [optional] Id of namespace which should be pre-selected
 832          * - all: [optional] Value of item for "all namespaces". If null or unset,
 833          *   no "<option>" is generated to select all namespaces.
 834          * - label: text for label to add before the field.
 835          * - exclude: [optional] Array of namespace ids to exclude.
 836          * - disable: [optional] Array of namespace ids for which the option should
 837          *   be disabled in the selector.
 838          * @param array $selectAttribs HTML attributes for the generated select element.
 839          * - id:   [optional], default: 'namespace'.
 840          * - name: [optional], default: 'namespace'.
 841          * @return string HTML code to select a namespace.
 842          */
 843         public static function namespaceSelector( array $params = array(),
 844                 array $selectAttribs = array()
 845         ) {
 846                 global $wgContLang;
 847
 848                 ksort( $selectAttribs );
 849
 850                 // Is a namespace selected?
 851                 if ( isset( $params['selected'] ) ) {
 852                         // If string only contains digits, convert to clean int. Selected could also
 853                         // be "all" or "" etc. which needs to be left untouched.
 854                         // PHP is_numeric() has issues with large strings, PHP ctype_digit has other issues
 855                         // and returns false for already clean ints. Use regex instead..
 856                         if ( preg_match( '/^\d+$/', $params['selected'] ) ) {
 857                                 $params['selected'] = intval( $params['selected'] );
 858                         }
 859                         // else: leaves it untouched for later processing
 860                 } else {
 861                         $params['selected'] = '';
 862                 }
 863
 864                 if ( !isset( $params['exclude'] ) || !is_array( $params['exclude'] ) ) {
 865                         $params['exclude'] = array();
 866                 }
 867                 if ( !isset( $params['disable'] ) || !is_array( $params['disable'] ) ) {
 868                         $params['disable'] = array();
 869                 }
 870
 871                 // Associative array between option-values and option-labels
 872                 $options = array();
 873
 874                 if ( isset( $params['all'] ) ) {
 875                         // add an option that would let the user select all namespaces.
 876                         // Value is provided by user, the name shown is localized for the user.
 877                         $options[$params['all']] = wfMessage( 'namespacesall' )->text();
 878                 }
 879                 // Add all namespaces as options (in the content language)
 880                 $options += $wgContLang->getFormattedNamespaces();
 881
 882                 // Convert $options to HTML and filter out namespaces below 0
 883                 $optionsHtml = array();
 884                 foreach ( $options as $nsId => $nsName ) {
 885                         if ( $nsId < NS_MAIN || in_array( $nsId, $params['exclude'] ) ) {
 886                                 continue;
 887                         }
 888                         if ( $nsId === NS_MAIN ) {
 889                                 // For other namespaces use the namespace prefix as label, but for
 890                                 // main we don't use "" but the user message describing it (e.g. "(Main)" or "(Article)")
 891                                 $nsName = wfMessage( 'blanknamespace' )->text();
 892                         } elseif ( is_int( $nsId ) ) {
 893                                 $nsName = $wgContLang->convertNamespace( $nsId );
 894                         }
 895                         $optionsHtml[] = Html::element(
 896                                 'option', array(
 897                                         'disabled' => in_array( $nsId, $params['disable'] ),
 898                                         'value' => $nsId,
 899                                         'selected' => $nsId === $params['selected'],
 900                                 ), $nsName
 901                         );
 902                 }
 903
 904                 if ( !array_key_exists( 'id', $selectAttribs ) ) {
 905                         $selectAttribs['id'] = 'namespace';
 906                 }
 907
 908                 if ( !array_key_exists( 'name', $selectAttribs ) ) {
 909                         $selectAttribs['name'] = 'namespace';
 910                 }
 911
 912                 $ret = '';
 913                 if ( isset( $params['label'] ) ) {
 914                         $ret .= Html::element(
 915                                 'label', array(
 916                                         'for' => isset( $selectAttribs['id'] ) ? $selectAttribs['id'] : null,
 917                                 ), $params['label']
 918                         ) . '&#160;';
 919                 }
 920
 921                 // Wrap options in a <select>
 922                 $ret .= Html::openElement( 'select', $selectAttribs )
 923                         . "\n"
 924                         . implode( "\n", $optionsHtml )
 925                         . "\n"
 926                         . Html::closeElement( 'select' );
 927
 928                 return $ret;
 929         }
 930
 931         /**
 932          * Constructs the opening html-tag with necessary doctypes depending on
 933          * global variables.
 934          *
 935          * @param array $attribs Associative array of miscellaneous extra
 936          *   attributes, passed to Html::element() of html tag.
 937          * @return string Raw HTML
 938          */
 939         public static function htmlHeader( $attribs = array() ) {
 940                 $ret = '';
 941
 942                 global $wgHtml5Version, $wgMimeType, $wgXhtmlNamespaces;
 943
 944                 $isXHTML = self::isXmlMimeType( $wgMimeType );
 945
 946                 if ( $isXHTML ) { // XHTML5
 947                         // XML MIME-typed markup should have an xml header.
 948                         // However a DOCTYPE is not needed.
 949                         $ret .= "<?xml version=\"1.0\" encoding=\"UTF-8\" ?" . ">\n";
 950
 951                         // Add the standard xmlns
 952                         $attribs['xmlns'] = 'http://www.w3.org/1999/xhtml';
 953
 954                         // And support custom namespaces
 955                         foreach ( $wgXhtmlNamespaces as $tag => $ns ) {
 956                                 $attribs["xmlns:$tag"] = $ns;
 957                         }
 958                 } else { // HTML5
 959                         // DOCTYPE
 960                         $ret .= "<!DOCTYPE html>\n";
 961                 }
 962
 963                 if ( $wgHtml5Version ) {
 964                         $attribs['version'] = $wgHtml5Version;
 965                 }
 966
 967                 $html = Html::openElement( 'html', $attribs );
 968
 969                 if ( $html ) {
 970                         $html .= "\n";
 971                 }
 972
 973                 $ret .= $html;
 974
 975                 return $ret;
 976         }
 977
 978         /**
 979          * Determines if the given MIME type is xml.
 980          *
 981          * @param string $mimetype MIME type
 982          * @return bool
 983          */
 984         public static function isXmlMimeType( $mimetype ) {
 985                 # http://www.whatwg.org/html/infrastructure.html#xml-mime-type
 986                 # * text/xml
 987                 # * application/xml
 988                 # * Any MIME type with a subtype ending in +xml (this implicitly includes application/xhtml+xml)
 989                 return (bool)preg_match( '!^(text|application)/xml$|^.+/.+\+xml$!', $mimetype );
 990         }
 991
 992         /**
 993          * Get HTML for an info box with an icon.
 994          *
 995          * @param string $text Wikitext, get this with wfMessage()->plain()
 996          * @param string $icon Path to icon file (used as 'src' attribute)
 997          * @param string $alt Alternate text for the icon
 998          * @param string $class Additional class name to add to the wrapper div
 999          *
1000          * @return string
1001          */
1002         static function infoBox( $text, $icon, $alt, $class = false ) {
1003                 $s = Html::openElement( 'div', array( 'class' => "mw-infobox $class" ) );
1004
1005                 $s .= Html::openElement( 'div', array( 'class' => 'mw-infobox-left' ) ) .
1006                                 Html::element( 'img',
1007                                         array(
1008                                                 'src' => $icon,
1009                                                 'alt' => $alt,
1010                                         )
1011                                 ) .
1012                                 Html::closeElement( 'div' );
1013
1014                 $s .= Html::openElement( 'div', array( 'class' => 'mw-infobox-right' ) ) .
1015                                 $text .
1016                                 Html::closeElement( 'div' );
1017                 $s .= Html::element( 'div', array( 'style' => 'clear: left;' ), ' ' );
1018
1019                 $s .= Html::closeElement( 'div' );
1020
1021                 $s .= Html::element( 'div', array( 'style' => 'clear: left;' ), ' ' );
1022
1023                 return $s;
1024         }
1025
1026         /**
1027          * Generate a srcset attribute value from an array mapping pixel densities
1028          * to URLs. Note that srcset supports width and height values as well, which
1029          * are not used here.
1030          *
1031          * @param array $urls
1032          * @return string
1033          */
1034         static function srcSet( $urls ) {
1035                 $candidates = array();
1036                 foreach ( $urls as $density => $url ) {
1037                         // Image candidate syntax per current whatwg live spec, 2012-09-23:
1038                         // http://www.whatwg.org/html/embedded-content-1.html#attr-img-srcset
1039                         $candidates[] = "{$url} {$density}x";
1040                 }
1041                 return implode( ", ", $candidates );
1042         }
1043 }