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 = [
  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 = [
  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 $attrs HTML attributes in an associative array
 108          * @param string[] $modifiers classes to add to the button
 109          * @see https://tools.wmflabs.org/styleguide/desktop/index.html for guidance on available modifiers
 110          * @return array $attrs A modified attribute array
 111          */
 112         public static function buttonAttributes( array $attrs, array $modifiers = [] ) {
 113                 global $wgUseMediaWikiUIEverywhere;
 114                 if ( $wgUseMediaWikiUIEverywhere ) {
 115                         if ( isset( $attrs['class'] ) ) {
 116                                 if ( is_array( $attrs['class'] ) ) {
 117                                         $attrs['class'][] = 'mw-ui-button';
 118                                         $attrs['class'] = array_merge( $attrs['class'], $modifiers );
 119                                         // ensure compatibility with Xml
 120                                         $attrs['class'] = implode( ' ', $attrs['class'] );
 121                                 } else {
 122                                         $attrs['class'] .= ' mw-ui-button ' . implode( ' ', $modifiers );
 123                                 }
 124                         } else {
 125                                 // ensure compatibility with Xml
 126                                 $attrs['class'] = 'mw-ui-button ' . implode( ' ', $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( array $attrs ) {
 140                 global $wgUseMediaWikiUIEverywhere;
 141                 if ( $wgUseMediaWikiUIEverywhere ) {
 142                         if ( isset( $attrs['class'] ) ) {
 143                                 if ( is_array( $attrs['class'] ) ) {
 144                                         $attrs['class'][] = 'mw-ui-input';
 145                                 } else {
 146                                         $attrs['class'] .= ' mw-ui-input';
 147                                 }
 148                         } else {
 149                                 $attrs['class'] = 'mw-ui-input';
 150                         }
 151                 }
 152                 return $attrs;
 153         }
 154
 155         /**
 156          * Returns an HTML link element in a string styled as a button
 157          * (when $wgUseMediaWikiUIEverywhere is enabled).
 158          *
 159          * @param string $contents The raw HTML contents of the element: *not*
 160          *   escaped!
 161          * @param array $attrs Associative array of attributes, e.g., array(
 162          *   'href' => 'http://www.mediawiki.org/' ). See expandAttributes() for
 163          *   further documentation.
 164          * @param string[] $modifiers classes to add to the button
 165          * @see http://tools.wmflabs.org/styleguide/desktop/index.html for guidance on available modifiers
 166          * @return string Raw HTML
 167          */
 168         public static function linkButton( $contents, array $attrs, array $modifiers = [] ) {
 169                 return self::element( 'a',
 170                         self::buttonAttributes( $attrs, $modifiers ),
 171                         $contents
 172                 );
 173         }
 174
 175         /**
 176          * Returns an HTML link element in a string styled as a button
 177          * (when $wgUseMediaWikiUIEverywhere is enabled).
 178          *
 179          * @param string $contents The raw HTML contents of the element: *not*
 180          *   escaped!
 181          * @param array $attrs Associative array of attributes, e.g., array(
 182          *   'href' => 'http://www.mediawiki.org/' ). See expandAttributes() for
 183          *   further documentation.
 184          * @param string[] $modifiers classes to add to the button
 185          * @see http://tools.wmflabs.org/styleguide/desktop/index.html for guidance on available modifiers
 186          * @return string Raw HTML
 187          */
 188         public static function submitButton( $contents, array $attrs, array $modifiers = [] ) {
 189                 $attrs['type'] = 'submit';
 190                 $attrs['value'] = $contents;
 191                 return self::element( 'input', self::buttonAttributes( $attrs, $modifiers ) );
 192         }
 193
 194         /**
 195          * Returns an HTML element in a string.  The major advantage here over
 196          * manually typing out the HTML is that it will escape all attribute
 197          * values.
 198          *
 199          * This is quite similar to Xml::tags(), but it implements some useful
 200          * HTML-specific logic.  For instance, there is no $allowShortTag
 201          * parameter: the closing tag is magically omitted if $element has an empty
 202          * content model.  If $wgWellFormedXml is false, then a few bytes will be
 203          * shaved off the HTML output as well.
 204          *
 205          * @param string $element The element's name, e.g., 'a'
 206          * @param array $attribs Associative array of attributes, e.g., array(
 207          *   'href' => 'http://www.mediawiki.org/' ). See expandAttributes() for
 208          *   further documentation.
 209          * @param string $contents The raw HTML contents of the element: *not*
 210          *   escaped!
 211          * @return string Raw HTML
 212          */
 213         public static function rawElement( $element, $attribs = [], $contents = '' ) {
 214                 global $wgWellFormedXml;
 215                 $start = self::openElement( $element, $attribs );
 216                 if ( in_array( $element, self::$voidElements ) ) {
 217                         if ( $wgWellFormedXml ) {
 218                                 // Silly XML.
 219                                 return substr( $start, 0, -1 ) . '/>';
 220                         }
 221                         return $start;
 222                 } else {
 223                         return "$start$contents" . self::closeElement( $element );
 224                 }
 225         }
 226
 227         /**
 228          * Identical to rawElement(), but HTML-escapes $contents (like
 229          * Xml::element()).
 230          *
 231          * @param string $element
 232          * @param array $attribs
 233          * @param string $contents
 234          *
 235          * @return string
 236          */
 237         public static function element( $element, $attribs = [], $contents = '' ) {
 238                 return self::rawElement( $element, $attribs, strtr( $contents, [
 239                         // There's no point in escaping quotes, >, etc. in the contents of
 240                         // elements.
 241                         '&' => '&amp;',
 242                         '<' => '&lt;'
 243                 ] ) );
 244         }
 245
 246         /**
 247          * Identical to rawElement(), but has no third parameter and omits the end
 248          * tag (and the self-closing '/' in XML mode for empty elements).
 249          *
 250          * @param string $element
 251          * @param array $attribs
 252          *
 253          * @return string
 254          */
 255         public static function openElement( $element, $attribs = [] ) {
 256                 $attribs = (array)$attribs;
 257                 // This is not required in HTML5, but let's do it anyway, for
 258                 // consistency and better compression.
 259                 $element = strtolower( $element );
 260
 261                 // Remove invalid input types
 262                 if ( $element == 'input' ) {
 263                         $validTypes = [
 264                                 'hidden',
 265                                 'text',
 266                                 'password',
 267                                 'checkbox',
 268                                 'radio',
 269                                 'file',
 270                                 'submit',
 271                                 'image',
 272                                 'reset',
 273                                 'button',
 274
 275                                 // HTML input types
 276                                 'datetime',
 277                                 'datetime-local',
 278                                 'date',
 279                                 'month',
 280                                 'time',
 281                                 'week',
 282                                 'number',
 283                                 'range',
 284                                 'email',
 285                                 'url',
 286                                 'search',
 287                                 'tel',
 288                                 'color',
 289                         ];
 290                         if ( isset( $attribs['type'] ) && !in_array( $attribs['type'], $validTypes ) ) {
 291                                 unset( $attribs['type'] );
 292                         }
 293                 }
 294
 295                 // According to standard the default type for <button> elements is "submit".
 296                 // Depending on compatibility mode IE might use "button", instead.
 297                 // We enforce the standard "submit".
 298                 if ( $element == 'button' && !isset( $attribs['type'] ) ) {
 299                         $attribs['type'] = 'submit';
 300                 }
 301
 302                 return "<$element" . self::expandAttributes(
 303                         self::dropDefaults( $element, $attribs ) ) . '>';
 304         }
 305
 306         /**
 307          * Returns "</$element>"
 308          *
 309          * @since 1.17
 310          * @param string $element Name of the element, e.g., 'a'
 311          * @return string A closing tag
 312          */
 313         public static function closeElement( $element ) {
 314                 $element = strtolower( $element );
 315
 316                 return "</$element>";
 317         }
 318
 319         /**
 320          * Given an element name and an associative array of element attributes,
 321          * return an array that is functionally identical to the input array, but
 322          * possibly smaller.  In particular, attributes might be stripped if they
 323          * are given their default values.
 324          *
 325          * This method is not guaranteed to remove all redundant attributes, only
 326          * some common ones and some others selected arbitrarily at random.  It
 327          * only guarantees that the output array should be functionally identical
 328          * to the input array (currently per the HTML 5 draft as of 2009-09-06).
 329          *
 330          * @param string $element Name of the element, e.g., 'a'
 331          * @param array $attribs Associative array of attributes, e.g., array(
 332          *   'href' => 'http://www.mediawiki.org/' ).  See expandAttributes() for
 333          *   further documentation.
 334          * @return array An array of attributes functionally identical to $attribs
 335          */
 336         private static function dropDefaults( $element, array $attribs ) {
 337                 // Whenever altering this array, please provide a covering test case
 338                 // in HtmlTest::provideElementsWithAttributesHavingDefaultValues
 339                 static $attribDefaults = [
 340                         'area' => [ 'shape' => 'rect' ],
 341                         'button' => [
 342                                 'formaction' => 'GET',
 343                                 'formenctype' => 'application/x-www-form-urlencoded',
 344                         ],
 345                         'canvas' => [
 346                                 'height' => '150',
 347                                 'width' => '300',
 348                         ],
 349                         'command' => [ 'type' => 'command' ],
 350                         'form' => [
 351                                 'action' => 'GET',
 352                                 'autocomplete' => 'on',
 353                                 'enctype' => 'application/x-www-form-urlencoded',
 354                         ],
 355                         'input' => [
 356                                 'formaction' => 'GET',
 357                                 'type' => 'text',
 358                         ],
 359                         'keygen' => [ 'keytype' => 'rsa' ],
 360                         'link' => [ 'media' => 'all' ],
 361                         'menu' => [ 'type' => 'list' ],
 362                         'script' => [ 'type' => 'text/javascript' ],
 363                         'style' => [
 364                                 'media' => 'all',
 365                                 'type' => 'text/css',
 366                         ],
 367                         'textarea' => [ 'wrap' => 'soft' ],
 368                 ];
 369
 370                 $element = strtolower( $element );
 371
 372                 foreach ( $attribs as $attrib => $value ) {
 373                         $lcattrib = strtolower( $attrib );
 374                         if ( is_array( $value ) ) {
 375                                 $value = implode( ' ', $value );
 376                         } else {
 377                                 $value = strval( $value );
 378                         }
 379
 380                         // Simple checks using $attribDefaults
 381                         if ( isset( $attribDefaults[$element][$lcattrib] )
 382                                 && $attribDefaults[$element][$lcattrib] == $value
 383                         ) {
 384                                 unset( $attribs[$attrib] );
 385                         }
 386
 387                         if ( $lcattrib == 'class' && $value == '' ) {
 388                                 unset( $attribs[$attrib] );
 389                         }
 390                 }
 391
 392                 // More subtle checks
 393                 if ( $element === 'link'
 394                         && isset( $attribs['type'] ) && strval( $attribs['type'] ) == 'text/css'
 395                 ) {
 396                         unset( $attribs['type'] );
 397                 }
 398                 if ( $element === 'input' ) {
 399                         $type = isset( $attribs['type'] ) ? $attribs['type'] : null;
 400                         $value = isset( $attribs['value'] ) ? $attribs['value'] : null;
 401                         if ( $type === 'checkbox' || $type === 'radio' ) {
 402                                 // The default value for checkboxes and radio buttons is 'on'
 403                                 // not ''. By stripping value="" we break radio boxes that
 404                                 // actually wants empty values.
 405                                 if ( $value === 'on' ) {
 406                                         unset( $attribs['value'] );
 407                                 }
 408                         } elseif ( $type === 'submit' ) {
 409                                 // The default value for submit appears to be "Submit" but
 410                                 // let's not bother stripping out localized text that matches
 411                                 // that.
 412                         } else {
 413                                 // The default value for nearly every other field type is ''
 414                                 // The 'range' and 'color' types use different defaults but
 415                                 // stripping a value="" does not hurt them.
 416                                 if ( $value === '' ) {
 417                                         unset( $attribs['value'] );
 418                                 }
 419                         }
 420                 }
 421                 if ( $element === 'select' && isset( $attribs['size'] ) ) {
 422                         if ( in_array( 'multiple', $attribs )
 423                                 || ( isset( $attribs['multiple'] ) && $attribs['multiple'] !== false )
 424                         ) {
 425                                 // A multi-select
 426                                 if ( strval( $attribs['size'] ) == '4' ) {
 427                                         unset( $attribs['size'] );
 428                                 }
 429                         } else {
 430                                 // Single select
 431                                 if ( strval( $attribs['size'] ) == '1' ) {
 432                                         unset( $attribs['size'] );
 433                                 }
 434                         }
 435                 }
 436
 437                 return $attribs;
 438         }
 439
 440         /**
 441          * Given an associative array of element attributes, generate a string
 442          * to stick after the element name in HTML output.  Like array( 'href' =>
 443          * 'http://www.mediawiki.org/' ) becomes something like
 444          * ' href="http://www.mediawiki.org"'.  Again, this is like
 445          * Xml::expandAttributes(), but it implements some HTML-specific logic.
 446          * For instance, it will omit quotation marks if $wgWellFormedXml is false,
 447          * and will treat boolean attributes specially.
 448          *
 449          * Attributes that can contain space-separated lists ('class', 'accesskey' and 'rel') array
 450          * values are allowed as well, which will automagically be normalized
 451          * and converted to a space-separated string. In addition to a numerical
 452          * array, the attribute value may also be an associative array. See the
 453          * example below for how that works.
 454          *
 455          * @par Numerical array
 456          * @code
 457          *     Html::element( 'em', array(
 458          *         'class' => array( 'foo', 'bar' )
 459          *     ) );
 460          *     // gives '<em class="foo bar"></em>'
 461          * @endcode
 462          *
 463          * @par Associative array
 464          * @code
 465          *     Html::element( 'em', array(
 466          *         'class' => array( 'foo', 'bar', 'foo' => false, 'quux' => true )
 467          *     ) );
 468          *     // gives '<em class="bar quux"></em>'
 469          * @endcode
 470          *
 471          * @param array $attribs Associative array of attributes, e.g., array(
 472          *   'href' => 'http://www.mediawiki.org/' ).  Values will be HTML-escaped.
 473          *   A value of false means to omit the attribute.  For boolean attributes,
 474          *   you can omit the key, e.g., array( 'checked' ) instead of
 475          *   array( 'checked' => 'checked' ) or such.
 476          *
 477          * @throws MWException If an attribute that doesn't allow lists is set to an array
 478          * @return string HTML fragment that goes between element name and '>'
 479          *   (starting with a space if at least one attribute is output)
 480          */
 481         public static function expandAttributes( array $attribs ) {
 482                 global $wgWellFormedXml;
 483
 484                 $ret = '';
 485                 foreach ( $attribs as $key => $value ) {
 486                         // Support intuitive array( 'checked' => true/false ) form
 487                         if ( $value === false || is_null( $value ) ) {
 488                                 continue;
 489                         }
 490
 491                         // For boolean attributes, support array( 'foo' ) instead of
 492                         // requiring array( 'foo' => 'meaningless' ).
 493                         if ( is_int( $key ) && in_array( strtolower( $value ), self::$boolAttribs ) ) {
 494                                 $key = $value;
 495                         }
 496
 497                         // Not technically required in HTML5 but we'd like consistency
 498                         // and better compression anyway.
 499                         $key = strtolower( $key );
 500
 501                         // Bug 23769: Blacklist all form validation attributes for now.  Current
 502                         // (June 2010) WebKit has no UI, so the form just refuses to submit
 503                         // without telling the user why, which is much worse than failing
 504                         // server-side validation.  Opera is the only other implementation at
 505                         // this time, and has ugly UI, so just kill the feature entirely until
 506                         // we have at least one good implementation.
 507
 508                         // As the default value of "1" for "step" rejects decimal
 509                         // numbers to be entered in 'type="number"' fields, allow
 510                         // the special case 'step="any"'.
 511
 512                         if ( in_array( $key, [ 'max', 'min', 'pattern', 'required' ] )
 513                                 || $key === 'step' && $value !== 'any' ) {
 514                                 continue;
 515                         }
 516
 517                         // http://www.w3.org/TR/html401/index/attributes.html ("space-separated")
 518                         // http://www.w3.org/TR/html5/index.html#attributes-1 ("space-separated")
 519                         $spaceSeparatedListAttributes = [
 520                                 'class', // html4, html5
 521                                 'accesskey', // as of html5, multiple space-separated values allowed
 522                                 // html4-spec doesn't document rel= as space-separated
 523                                 // but has been used like that and is now documented as such
 524                                 // in the html5-spec.
 525                                 'rel',
 526                         ];
 527
 528                         // Specific features for attributes that allow a list of space-separated values
 529                         if ( in_array( $key, $spaceSeparatedListAttributes ) ) {
 530                                 // Apply some normalization and remove duplicates
 531
 532                                 // Convert into correct array. Array can contain space-separated
 533                                 // values. Implode/explode to get those into the main array as well.
 534                                 if ( is_array( $value ) ) {
 535                                         // If input wasn't an array, we can skip this step
 536                                         $newValue = [];
 537                                         foreach ( $value as $k => $v ) {
 538                                                 if ( is_string( $v ) ) {
 539                                                         // String values should be normal `array( 'foo' )`
 540                                                         // Just append them
 541                                                         if ( !isset( $value[$v] ) ) {
 542                                                                 // As a special case don't set 'foo' if a
 543                                                                 // separate 'foo' => true/false exists in the array
 544                                                                 // keys should be authoritative
 545                                                                 $newValue[] = $v;
 546                                                         }
 547                                                 } elseif ( $v ) {
 548                                                         // If the value is truthy but not a string this is likely
 549                                                         // an array( 'foo' => true ), falsy values don't add strings
 550                                                         $newValue[] = $k;
 551                                                 }
 552                                         }
 553                                         $value = implode( ' ', $newValue );
 554                                 }
 555                                 $value = explode( ' ', $value );
 556
 557                                 // Normalize spacing by fixing up cases where people used
 558                                 // more than 1 space and/or a trailing/leading space
 559                                 $value = array_diff( $value, [ '', ' ' ] );
 560
 561                                 // Remove duplicates and create the string
 562                                 $value = implode( ' ', array_unique( $value ) );
 563                         } elseif ( is_array( $value ) ) {
 564                                 throw new MWException( "HTML attribute $key can not contain a list of values" );
 565                         }
 566
 567                         // See the "Attributes" section in the HTML syntax part of HTML5,
 568                         // 9.1.2.3 as of 2009-08-10.  Most attributes can have quotation
 569                         // marks omitted, but not all.  (Although a literal " is not
 570                         // permitted, we don't check for that, since it will be escaped
 571                         // anyway.)
 572
 573                         // See also research done on further characters that need to be
 574                         // escaped: http://code.google.com/p/html5lib/issues/detail?id=93
 575                         $badChars = "\\x00- '=<>`/\x{00a0}\x{1680}\x{180e}\x{180F}\x{2000}\x{2001}"
 576                                 . "\x{2002}\x{2003}\x{2004}\x{2005}\x{2006}\x{2007}\x{2008}\x{2009}"
 577                                 . "\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}";
 578                         if ( $wgWellFormedXml || $value === '' || preg_match( "![$badChars]!u", $value ) ) {
 579                                 $quote = '"';
 580                         } else {
 581                                 $quote = '';
 582                         }
 583
 584                         if ( in_array( $key, self::$boolAttribs ) ) {
 585                                 // In HTML5, we can leave the value empty. If we don't need
 586                                 // well-formed XML, we can omit the = entirely.
 587                                 if ( !$wgWellFormedXml ) {
 588                                         $ret .= " $key";
 589                                 } else {
 590                                         $ret .= " $key=\"\"";
 591                                 }
 592                         } else {
 593                                 // Apparently we need to entity-encode \n, \r, \t, although the
 594                                 // spec doesn't mention that.  Since we're doing strtr() anyway,
 595                                 // we may as well not call htmlspecialchars().
 596                                 // @todo FIXME: Verify that we actually need to
 597                                 // escape \n\r\t here, and explain why, exactly.
 598                                 // We could call Sanitizer::encodeAttribute() for this, but we
 599                                 // don't because we're stubborn and like our marginal savings on
 600                                 // byte size from not having to encode unnecessary quotes.
 601                                 // The only difference between this transform and the one by
 602                                 // Sanitizer::encodeAttribute() is '<' is only encoded here if
 603                                 // $wgWellFormedXml is set, and ' is not encoded.
 604                                 $map = [
 605                                         '&' => '&amp;',
 606                                         '"' => '&quot;',
 607                                         '>' => '&gt;',
 608                                         "\n" => '&#10;',
 609                                         "\r" => '&#13;',
 610                                         "\t" => '&#9;'
 611                                 ];
 612                                 if ( $wgWellFormedXml ) {
 613                                         // This is allowed per spec: <http://www.w3.org/TR/xml/#NT-AttValue>
 614                                         // But reportedly it breaks some XML tools?
 615                                         // @todo FIXME: Is this really true?
 616                                         $map['<'] = '&lt;';
 617                                 }
 618                                 $ret .= " $key=$quote" . strtr( $value, $map ) . $quote;
 619                         }
 620                 }
 621                 return $ret;
 622         }
 623
 624         /**
 625          * Output a "<script>" tag with the given contents.
 626          *
 627          * @todo do some useful escaping as well, like if $contents contains
 628          * literal "</script>" or (for XML) literal "]]>".
 629          *
 630          * @param string $contents JavaScript
 631          * @return string Raw HTML
 632          */
 633         public static function inlineScript( $contents ) {
 634                 global $wgWellFormedXml;
 635
 636                 $attrs = [];
 637
 638                 if ( $wgWellFormedXml && preg_match( '/[<&]/', $contents ) ) {
 639                         $contents = "/*<![CDATA[*/$contents/*]]>*/";
 640                 }
 641
 642                 return self::rawElement( 'script', $attrs, $contents );
 643         }
 644
 645         /**
 646          * Output a "<script>" tag linking to the given URL, e.g.,
 647          * "<script src=foo.js></script>".
 648          *
 649          * @param string $url
 650          * @return string Raw HTML
 651          */
 652         public static function linkedScript( $url ) {
 653                 $attrs = [ 'src' => $url ];
 654
 655                 return self::element( 'script', $attrs );
 656         }
 657
 658         /**
 659          * Output a "<style>" tag with the given contents for the given media type
 660          * (if any).  TODO: do some useful escaping as well, like if $contents
 661          * contains literal "</style>" (admittedly unlikely).
 662          *
 663          * @param string $contents CSS
 664          * @param string $media A media type string, like 'screen'
 665          * @return string Raw HTML
 666          */
 667         public static function inlineStyle( $contents, $media = 'all' ) {
 668                 global $wgWellFormedXml;
 669
 670                 if ( $wgWellFormedXml && preg_match( '/[<&]/', $contents ) ) {
 671                         $contents = "/*<![CDATA[*/$contents/*]]>*/";
 672                 }
 673
 674                 return self::rawElement( 'style', [
 675                         'media' => $media,
 676                 ], $contents );
 677         }
 678
 679         /**
 680          * Output a "<link rel=stylesheet>" linking to the given URL for the given
 681          * media type (if any).
 682          *
 683          * @param string $url
 684          * @param string $media A media type string, like 'screen'
 685          * @return string Raw HTML
 686          */
 687         public static function linkedStyle( $url, $media = 'all' ) {
 688                 return self::element( 'link', [
 689                         'rel' => 'stylesheet',
 690                         'href' => $url,
 691                         'media' => $media,
 692                 ] );
 693         }
 694
 695         /**
 696          * Convenience function to produce an "<input>" element.  This supports the
 697          * new HTML5 input types and attributes.
 698          *
 699          * @param string $name Name attribute
 700          * @param string $value Value attribute
 701          * @param string $type Type attribute
 702          * @param array $attribs Associative array of miscellaneous extra
 703          *   attributes, passed to Html::element()
 704          * @return string Raw HTML
 705          */
 706         public static function input( $name, $value = '', $type = 'text', array $attribs = [] ) {
 707                 $attribs['type'] = $type;
 708                 $attribs['value'] = $value;
 709                 $attribs['name'] = $name;
 710                 if ( in_array( $type, [ 'text', 'search', 'email', 'password', 'number' ] ) ) {
 711                         $attribs = self::getTextInputAttributes( $attribs );
 712                 }
 713                 if ( in_array( $type, [ 'button', 'reset', 'submit' ] ) ) {
 714                         $attribs = self::buttonAttributes( $attribs );
 715                 }
 716                 return self::element( 'input', $attribs );
 717         }
 718
 719         /**
 720          * Convenience function to produce a checkbox (input element with type=checkbox)
 721          *
 722          * @param string $name Name attribute
 723          * @param bool $checked Whether the checkbox is checked or not
 724          * @param array $attribs Array of additional attributes
 725          * @return string Raw HTML
 726          */
 727         public static function check( $name, $checked = false, array $attribs = [] ) {
 728                 if ( isset( $attribs['value'] ) ) {
 729                         $value = $attribs['value'];
 730                         unset( $attribs['value'] );
 731                 } else {
 732                         $value = 1;
 733                 }
 734
 735                 if ( $checked ) {
 736                         $attribs[] = 'checked';
 737                 }
 738
 739                 return self::input( $name, $value, 'checkbox', $attribs );
 740         }
 741
 742         /**
 743          * Convenience function to produce a radio button (input element with type=radio)
 744          *
 745          * @param string $name Name attribute
 746          * @param bool $checked Whether the radio button is checked or not
 747          * @param array $attribs Array of additional attributes
 748          * @return string Raw HTML
 749          */
 750         public static function radio( $name, $checked = false, array $attribs = [] ) {
 751                 if ( isset( $attribs['value'] ) ) {
 752                         $value = $attribs['value'];
 753                         unset( $attribs['value'] );
 754                 } else {
 755                         $value = 1;
 756                 }
 757
 758                 if ( $checked ) {
 759                         $attribs[] = 'checked';
 760                 }
 761
 762                 return self::input( $name, $value, 'radio', $attribs );
 763         }
 764
 765         /**
 766          * Convenience function for generating a label for inputs.
 767          *
 768          * @param string $label Contents of the label
 769          * @param string $id ID of the element being labeled
 770          * @param array $attribs Additional attributes
 771          * @return string Raw HTML
 772          */
 773         public static function label( $label, $id, array $attribs = [] ) {
 774                 $attribs += [
 775                         'for' => $id
 776                 ];
 777                 return self::element( 'label', $attribs, $label );
 778         }
 779
 780         /**
 781          * Convenience function to produce an input element with type=hidden
 782          *
 783          * @param string $name Name attribute
 784          * @param string $value Value attribute
 785          * @param array $attribs Associative array of miscellaneous extra
 786          *   attributes, passed to Html::element()
 787          * @return string Raw HTML
 788          */
 789         public static function hidden( $name, $value, array $attribs = [] ) {
 790                 return self::input( $name, $value, 'hidden', $attribs );
 791         }
 792
 793         /**
 794          * Convenience function to produce a <textarea> element.
 795          *
 796          * This supports leaving out the cols= and rows= which Xml requires and are
 797          * required by HTML4/XHTML but not required by HTML5.
 798          *
 799          * @param string $name Name attribute
 800          * @param string $value Value attribute
 801          * @param array $attribs Associative array of miscellaneous extra
 802          *   attributes, passed to Html::element()
 803          * @return string Raw HTML
 804          */
 805         public static function textarea( $name, $value = '', array $attribs = [] ) {
 806                 $attribs['name'] = $name;
 807
 808                 if ( substr( $value, 0, 1 ) == "\n" ) {
 809                         // Workaround for bug 12130: browsers eat the initial newline
 810                         // assuming that it's just for show, but they do keep the later
 811                         // newlines, which we may want to preserve during editing.
 812                         // Prepending a single newline
 813                         $spacedValue = "\n" . $value;
 814                 } else {
 815                         $spacedValue = $value;
 816                 }
 817                 return self::element( 'textarea', self::getTextInputAttributes( $attribs ), $spacedValue );
 818         }
 819
 820         /**
 821          * Helper for Html::namespaceSelector().
 822          * @param array $params See Html::namespaceSelector()
 823          * @return array
 824          */
 825         public static function namespaceSelectorOptions( array $params = [] ) {
 826                 global $wgContLang;
 827
 828                 $options = [];
 829
 830                 if ( !isset( $params['exclude'] ) || !is_array( $params['exclude'] ) ) {
 831                         $params['exclude'] = [];
 832                 }
 833
 834                 if ( isset( $params['all'] ) ) {
 835                         // add an option that would let the user select all namespaces.
 836                         // Value is provided by user, the name shown is localized for the user.
 837                         $options[$params['all']] = wfMessage( 'namespacesall' )->text();
 838                 }
 839                 // Add all namespaces as options (in the content language)
 840                 $options += $wgContLang->getFormattedNamespaces();
 841
 842                 $optionsOut = [];
 843                 // Filter out namespaces below 0 and massage labels
 844                 foreach ( $options as $nsId => $nsName ) {
 845                         if ( $nsId < NS_MAIN || in_array( $nsId, $params['exclude'] ) ) {
 846                                 continue;
 847                         }
 848                         if ( $nsId === NS_MAIN ) {
 849                                 // For other namespaces use the namespace prefix as label, but for
 850                                 // main we don't use "" but the user message describing it (e.g. "(Main)" or "(Article)")
 851                                 $nsName = wfMessage( 'blanknamespace' )->text();
 852                         } elseif ( is_int( $nsId ) ) {
 853                                 $nsName = $wgContLang->convertNamespace( $nsId );
 854                         }
 855                         $optionsOut[$nsId] = $nsName;
 856                 }
 857
 858                 return $optionsOut;
 859         }
 860
 861         /**
 862          * Build a drop-down box for selecting a namespace
 863          *
 864          * @param array $params Params to set.
 865          * - selected: [optional] Id of namespace which should be pre-selected
 866          * - all: [optional] Value of item for "all namespaces". If null or unset,
 867          *   no "<option>" is generated to select all namespaces.
 868          * - label: text for label to add before the field.
 869          * - exclude: [optional] Array of namespace ids to exclude.
 870          * - disable: [optional] Array of namespace ids for which the option should
 871          *   be disabled in the selector.
 872          * @param array $selectAttribs HTML attributes for the generated select element.
 873          * - id:   [optional], default: 'namespace'.
 874          * - name: [optional], default: 'namespace'.
 875          * @return string HTML code to select a namespace.
 876          */
 877         public static function namespaceSelector( array $params = [],
 878                 array $selectAttribs = []
 879         ) {
 880                 ksort( $selectAttribs );
 881
 882                 // Is a namespace selected?
 883                 if ( isset( $params['selected'] ) ) {
 884                         // If string only contains digits, convert to clean int. Selected could also
 885                         // be "all" or "" etc. which needs to be left untouched.
 886                         // PHP is_numeric() has issues with large strings, PHP ctype_digit has other issues
 887                         // and returns false for already clean ints. Use regex instead..
 888                         if ( preg_match( '/^\d+$/', $params['selected'] ) ) {
 889                                 $params['selected'] = intval( $params['selected'] );
 890                         }
 891                         // else: leaves it untouched for later processing
 892                 } else {
 893                         $params['selected'] = '';
 894                 }
 895
 896                 if ( !isset( $params['disable'] ) || !is_array( $params['disable'] ) ) {
 897                         $params['disable'] = [];
 898                 }
 899
 900                 // Associative array between option-values and option-labels
 901                 $options = self::namespaceSelectorOptions( $params );
 902
 903                 // Convert $options to HTML
 904                 $optionsHtml = [];
 905                 foreach ( $options as $nsId => $nsName ) {
 906                         $optionsHtml[] = self::element(
 907                                 'option', [
 908                                         'disabled' => in_array( $nsId, $params['disable'] ),
 909                                         'value' => $nsId,
 910                                         'selected' => $nsId === $params['selected'],
 911                                 ], $nsName
 912                         );
 913                 }
 914
 915                 if ( !array_key_exists( 'id', $selectAttribs ) ) {
 916                         $selectAttribs['id'] = 'namespace';
 917                 }
 918
 919                 if ( !array_key_exists( 'name', $selectAttribs ) ) {
 920                         $selectAttribs['name'] = 'namespace';
 921                 }
 922
 923                 $ret = '';
 924                 if ( isset( $params['label'] ) ) {
 925                         $ret .= self::element(
 926                                 'label', [
 927                                         'for' => isset( $selectAttribs['id'] ) ? $selectAttribs['id'] : null,
 928                                 ], $params['label']
 929                         ) . '&#160;';
 930                 }
 931
 932                 // Wrap options in a <select>
 933                 $ret .= self::openElement( 'select', $selectAttribs )
 934                         . "\n"
 935                         . implode( "\n", $optionsHtml )
 936                         . "\n"
 937                         . self::closeElement( 'select' );
 938
 939                 return $ret;
 940         }
 941
 942         /**
 943          * Constructs the opening html-tag with necessary doctypes depending on
 944          * global variables.
 945          *
 946          * @param array $attribs Associative array of miscellaneous extra
 947          *   attributes, passed to Html::element() of html tag.
 948          * @return string Raw HTML
 949          */
 950         public static function htmlHeader( array $attribs = [] ) {
 951                 $ret = '';
 952
 953                 global $wgHtml5Version, $wgMimeType, $wgXhtmlNamespaces;
 954
 955                 $isXHTML = self::isXmlMimeType( $wgMimeType );
 956
 957                 if ( $isXHTML ) { // XHTML5
 958                         // XML MIME-typed markup should have an xml header.
 959                         // However a DOCTYPE is not needed.
 960                         $ret .= "<?xml version=\"1.0\" encoding=\"UTF-8\" ?" . ">\n";
 961
 962                         // Add the standard xmlns
 963                         $attribs['xmlns'] = 'http://www.w3.org/1999/xhtml';
 964
 965                         // And support custom namespaces
 966                         foreach ( $wgXhtmlNamespaces as $tag => $ns ) {
 967                                 $attribs["xmlns:$tag"] = $ns;
 968                         }
 969                 } else { // HTML5
 970                         // DOCTYPE
 971                         $ret .= "<!DOCTYPE html>\n";
 972                 }
 973
 974                 if ( $wgHtml5Version ) {
 975                         $attribs['version'] = $wgHtml5Version;
 976                 }
 977
 978                 $html = self::openElement( 'html', $attribs );
 979
 980                 if ( $html ) {
 981                         $html .= "\n";
 982                 }
 983
 984                 $ret .= $html;
 985
 986                 return $ret;
 987         }
 988
 989         /**
 990          * Determines if the given MIME type is xml.
 991          *
 992          * @param string $mimetype MIME type
 993          * @return bool
 994          */
 995         public static function isXmlMimeType( $mimetype ) {
 996                 # http://www.whatwg.org/html/infrastructure.html#xml-mime-type
 997                 # * text/xml
 998                 # * application/xml
 999                 # * Any MIME type with a subtype ending in +xml (this implicitly includes application/xhtml+xml)
1000                 return (bool)preg_match( '!^(text|application)/xml$|^.+/.+\+xml$!', $mimetype );
1001         }
1002
1003         /**
1004          * Get HTML for an info box with an icon.
1005          *
1006          * @param string $text Wikitext, get this with wfMessage()->plain()
1007          * @param string $icon Path to icon file (used as 'src' attribute)
1008          * @param string $alt Alternate text for the icon
1009          * @param string $class Additional class name to add to the wrapper div
1010          *
1011          * @return string
1012          */
1013         static function infoBox( $text, $icon, $alt, $class = '' ) {
1014                 $s = self::openElement( 'div', [ 'class' => "mw-infobox $class" ] );
1015
1016                 $s .= self::openElement( 'div', [ 'class' => 'mw-infobox-left' ] ) .
1017                                 self::element( 'img',
1018                                         [
1019                                                 'src' => $icon,
1020                                                 'alt' => $alt,
1021                                         ]
1022                                 ) .
1023                                 self::closeElement( 'div' );
1024
1025                 $s .= self::openElement( 'div', [ 'class' => 'mw-infobox-right' ] ) .
1026                                 $text .
1027                                 self::closeElement( 'div' );
1028                 $s .= self::element( 'div', [ 'style' => 'clear: left;' ], ' ' );
1029
1030                 $s .= self::closeElement( 'div' );
1031
1032                 $s .= self::element( 'div', [ 'style' => 'clear: left;' ], ' ' );
1033
1034                 return $s;
1035         }
1036
1037         /**
1038          * Generate a srcset attribute value.
1039          *
1040          * Generates a srcset attribute value from an array mapping pixel densities
1041          * to URLs. A trailing 'x' in pixel density values is optional.
1042          *
1043          * @note srcset width and height values are not supported.
1044          *
1045          * @see http://www.whatwg.org/html/embedded-content-1.html#attr-img-srcset
1046          *
1047          * @par Example:
1048          * @code
1049          *     Html::srcSet( array(
1050          *         '1x'   => 'standard.jpeg',
1051          *         '1.5x' => 'large.jpeg',
1052          *         '3x'   => 'extra-large.jpeg',
1053          *     ) );
1054          *     // gives 'standard.jpeg 1x, large.jpeg 1.5x, extra-large.jpeg 2x'
1055          * @endcode
1056          *
1057          * @param string[] $urls
1058          * @return string
1059          */
1060         static function srcSet( array $urls ) {
1061                 $candidates = [];
1062                 foreach ( $urls as $density => $url ) {
1063                         // Cast density to float to strip 'x'.
1064                         $candidates[] = $url . ' ' . (float)$density . 'x';
1065                 }
1066                 return implode( ", ", $candidates );
1067         }
1068 }