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  *
  42  * This class is meant to be confined to utility functions that are called from
  43  * trusted code paths.  It does not do enforcement of policy like not allowing
  44  * <a> elements.
  45  *
  46  * @since 1.16
  47  */
  48 class Html {
  49         // List of void elements from HTML5, section 8.1.2 as of 2011-08-12
  50         private static $voidElements = [
  51                 'area',
  52                 'base',
  53                 'br',
  54                 'col',
  55                 'command',
  56                 'embed',
  57                 'hr',
  58                 'img',
  59                 'input',
  60                 'keygen',
  61                 'link',
  62                 'meta',
  63                 'param',
  64                 'source',
  65                 'track',
  66                 'wbr',
  67         ];
  68
  69         // Boolean attributes, which may have the value omitted entirely.  Manually
  70         // collected from the HTML5 spec as of 2011-08-12.
  71         private static $boolAttribs = [
  72                 'async',
  73                 'autofocus',
  74                 'autoplay',
  75                 'checked',
  76                 'controls',
  77                 'default',
  78                 'defer',
  79                 'disabled',
  80                 'formnovalidate',
  81                 'hidden',
  82                 'ismap',
  83                 'itemscope',
  84                 'loop',
  85                 'multiple',
  86                 'muted',
  87                 'novalidate',
  88                 'open',
  89                 'pubdate',
  90                 'readonly',
  91                 'required',
  92                 'reversed',
  93                 'scoped',
  94                 'seamless',
  95                 'selected',
  96                 'truespeed',
  97                 'typemustmatch',
  98                 // HTML5 Microdata
  99                 'itemscope',
 100         ];
 101
 102         /**
 103          * Modifies a set of attributes meant for button elements
 104          * and apply a set of default attributes when $wgUseMediaWikiUIEverywhere enabled.
 105          * @param array $attrs HTML attributes in an associative array
 106          * @param string[] $modifiers classes to add to the button
 107          * @see https://tools.wmflabs.org/styleguide/desktop/index.html for guidance on available modifiers
 108          * @return array $attrs A modified attribute array
 109          */
 110         public static function buttonAttributes( array $attrs, array $modifiers = [] ) {
 111                 global $wgUseMediaWikiUIEverywhere;
 112                 if ( $wgUseMediaWikiUIEverywhere ) {
 113                         if ( isset( $attrs['class'] ) ) {
 114                                 if ( is_array( $attrs['class'] ) ) {
 115                                         $attrs['class'][] = 'mw-ui-button';
 116                                         $attrs['class'] = array_merge( $attrs['class'], $modifiers );
 117                                         // ensure compatibility with Xml
 118                                         $attrs['class'] = implode( ' ', $attrs['class'] );
 119                                 } else {
 120                                         $attrs['class'] .= ' mw-ui-button ' . implode( ' ', $modifiers );
 121                                 }
 122                         } else {
 123                                 // ensure compatibility with Xml
 124                                 $attrs['class'] = 'mw-ui-button ' . implode( ' ', $modifiers );
 125                         }
 126                 }
 127                 return $attrs;
 128         }
 129
 130         /**
 131          * Modifies a set of attributes meant for text input elements
 132          * and apply a set of default attributes.
 133          * Removes size attribute when $wgUseMediaWikiUIEverywhere enabled.
 134          * @param array $attrs An attribute array.
 135          * @return array $attrs A modified attribute array
 136          */
 137         public static function getTextInputAttributes( array $attrs ) {
 138                 global $wgUseMediaWikiUIEverywhere;
 139                 if ( $wgUseMediaWikiUIEverywhere ) {
 140                         if ( isset( $attrs['class'] ) ) {
 141                                 if ( is_array( $attrs['class'] ) ) {
 142                                         $attrs['class'][] = 'mw-ui-input';
 143                                 } else {
 144                                         $attrs['class'] .= ' mw-ui-input';
 145                                 }
 146                         } else {
 147                                 $attrs['class'] = 'mw-ui-input';
 148                         }
 149                 }
 150                 return $attrs;
 151         }
 152
 153         /**
 154          * Returns an HTML link element in a string styled as a button
 155          * (when $wgUseMediaWikiUIEverywhere is enabled).
 156          *
 157          * @param string $contents The raw HTML contents of the element: *not*
 158          *   escaped!
 159          * @param array $attrs Associative array of attributes, e.g., array(
 160          *   'href' => 'http://www.mediawiki.org/' ). See expandAttributes() for
 161          *   further documentation.
 162          * @param string[] $modifiers classes to add to the button
 163          * @see http://tools.wmflabs.org/styleguide/desktop/index.html for guidance on available modifiers
 164          * @return string Raw HTML
 165          */
 166         public static function linkButton( $contents, array $attrs, array $modifiers = [] ) {
 167                 return self::element( 'a',
 168                         self::buttonAttributes( $attrs, $modifiers ),
 169                         $contents
 170                 );
 171         }
 172
 173         /**
 174          * Returns an HTML link element in a string styled as a button
 175          * (when $wgUseMediaWikiUIEverywhere is enabled).
 176          *
 177          * @param string $contents The raw HTML contents of the element: *not*
 178          *   escaped!
 179          * @param array $attrs Associative array of attributes, e.g., array(
 180          *   'href' => 'http://www.mediawiki.org/' ). See expandAttributes() for
 181          *   further documentation.
 182          * @param string[] $modifiers classes to add to the button
 183          * @see http://tools.wmflabs.org/styleguide/desktop/index.html for guidance on available modifiers
 184          * @return string Raw HTML
 185          */
 186         public static function submitButton( $contents, array $attrs, array $modifiers = [] ) {
 187                 $attrs['type'] = 'submit';
 188                 $attrs['value'] = $contents;
 189                 return self::element( 'input', self::buttonAttributes( $attrs, $modifiers ) );
 190         }
 191
 192         /**
 193          * Returns an HTML element in a string.  The major advantage here over
 194          * manually typing out the HTML is that it will escape all attribute
 195          * values.
 196          *
 197          * This is quite similar to Xml::tags(), but it implements some useful
 198          * HTML-specific logic.  For instance, there is no $allowShortTag
 199          * parameter: the closing tag is magically omitted if $element has an empty
 200          * content model.
 201          *
 202          * @param string $element The element's name, e.g., 'a'
 203          * @param array $attribs Associative array of attributes, e.g., array(
 204          *   'href' => 'http://www.mediawiki.org/' ). See expandAttributes() for
 205          *   further documentation.
 206          * @param string $contents The raw HTML contents of the element: *not*
 207          *   escaped!
 208          * @return string Raw HTML
 209          */
 210         public static function rawElement( $element, $attribs = [], $contents = '' ) {
 211                 $start = self::openElement( $element, $attribs );
 212                 if ( in_array( $element, self::$voidElements ) ) {
 213                         // Silly XML.
 214                         return substr( $start, 0, -1 ) . '/>';
 215                 } else {
 216                         return "$start$contents" . self::closeElement( $element );
 217                 }
 218         }
 219
 220         /**
 221          * Identical to rawElement(), but HTML-escapes $contents (like
 222          * Xml::element()).
 223          *
 224          * @param string $element
 225          * @param array $attribs
 226          * @param string $contents
 227          *
 228          * @return string
 229          */
 230         public static function element( $element, $attribs = [], $contents = '' ) {
 231                 return self::rawElement( $element, $attribs, strtr( $contents, [
 232                         // There's no point in escaping quotes, >, etc. in the contents of
 233                         // elements.
 234                         '&' => '&amp;',
 235                         '<' => '&lt;'
 236                 ] ) );
 237         }
 238
 239         /**
 240          * Identical to rawElement(), but has no third parameter and omits the end
 241          * tag (and the self-closing '/' in XML mode for empty elements).
 242          *
 243          * @param string $element
 244          * @param array $attribs
 245          *
 246          * @return string
 247          */
 248         public static function openElement( $element, $attribs = [] ) {
 249                 $attribs = (array)$attribs;
 250                 // This is not required in HTML5, but let's do it anyway, for
 251                 // consistency and better compression.
 252                 $element = strtolower( $element );
 253
 254                 // Remove invalid input types
 255                 if ( $element == 'input' ) {
 256                         $validTypes = [
 257                                 'hidden',
 258                                 'text',
 259                                 'password',
 260                                 'checkbox',
 261                                 'radio',
 262                                 'file',
 263                                 'submit',
 264                                 'image',
 265                                 'reset',
 266                                 'button',
 267
 268                                 // HTML input types
 269                                 'datetime',
 270                                 'datetime-local',
 271                                 'date',
 272                                 'month',
 273                                 'time',
 274                                 'week',
 275                                 'number',
 276                                 'range',
 277                                 'email',
 278                                 'url',
 279                                 'search',
 280                                 'tel',
 281                                 'color',
 282                         ];
 283                         if ( isset( $attribs['type'] ) && !in_array( $attribs['type'], $validTypes ) ) {
 284                                 unset( $attribs['type'] );
 285                         }
 286                 }
 287
 288                 // According to standard the default type for <button> elements is "submit".
 289                 // Depending on compatibility mode IE might use "button", instead.
 290                 // We enforce the standard "submit".
 291                 if ( $element == 'button' && !isset( $attribs['type'] ) ) {
 292                         $attribs['type'] = 'submit';
 293                 }
 294
 295                 return "<$element" . self::expandAttributes(
 296                         self::dropDefaults( $element, $attribs ) ) . '>';
 297         }
 298
 299         /**
 300          * Returns "</$element>"
 301          *
 302          * @since 1.17
 303          * @param string $element Name of the element, e.g., 'a'
 304          * @return string A closing tag
 305          */
 306         public static function closeElement( $element ) {
 307                 $element = strtolower( $element );
 308
 309                 return "</$element>";
 310         }
 311
 312         /**
 313          * Given an element name and an associative array of element attributes,
 314          * return an array that is functionally identical to the input array, but
 315          * possibly smaller.  In particular, attributes might be stripped if they
 316          * are given their default values.
 317          *
 318          * This method is not guaranteed to remove all redundant attributes, only
 319          * some common ones and some others selected arbitrarily at random.  It
 320          * only guarantees that the output array should be functionally identical
 321          * to the input array (currently per the HTML 5 draft as of 2009-09-06).
 322          *
 323          * @param string $element Name of the element, e.g., 'a'
 324          * @param array $attribs Associative array of attributes, e.g., array(
 325          *   'href' => 'http://www.mediawiki.org/' ).  See expandAttributes() for
 326          *   further documentation.
 327          * @return array An array of attributes functionally identical to $attribs
 328          */
 329         private static function dropDefaults( $element, array $attribs ) {
 330                 // Whenever altering this array, please provide a covering test case
 331                 // in HtmlTest::provideElementsWithAttributesHavingDefaultValues
 332                 static $attribDefaults = [
 333                         'area' => [ 'shape' => 'rect' ],
 334                         'button' => [
 335                                 'formaction' => 'GET',
 336                                 'formenctype' => 'application/x-www-form-urlencoded',
 337                         ],
 338                         'canvas' => [
 339                                 'height' => '150',
 340                                 'width' => '300',
 341                         ],
 342                         'command' => [ 'type' => 'command' ],
 343                         'form' => [
 344                                 'action' => 'GET',
 345                                 'autocomplete' => 'on',
 346                                 'enctype' => 'application/x-www-form-urlencoded',
 347                         ],
 348                         'input' => [
 349                                 'formaction' => 'GET',
 350                                 'type' => 'text',
 351                         ],
 352                         'keygen' => [ 'keytype' => 'rsa' ],
 353                         'link' => [ 'media' => 'all' ],
 354                         'menu' => [ 'type' => 'list' ],
 355                         'script' => [ 'type' => 'text/javascript' ],
 356                         'style' => [
 357                                 'media' => 'all',
 358                                 'type' => 'text/css',
 359                         ],
 360                         'textarea' => [ 'wrap' => 'soft' ],
 361                 ];
 362
 363                 $element = strtolower( $element );
 364
 365                 foreach ( $attribs as $attrib => $value ) {
 366                         $lcattrib = strtolower( $attrib );
 367                         if ( is_array( $value ) ) {
 368                                 $value = implode( ' ', $value );
 369                         } else {
 370                                 $value = strval( $value );
 371                         }
 372
 373                         // Simple checks using $attribDefaults
 374                         if ( isset( $attribDefaults[$element][$lcattrib] )
 375                                 && $attribDefaults[$element][$lcattrib] == $value
 376                         ) {
 377                                 unset( $attribs[$attrib] );
 378                         }
 379
 380                         if ( $lcattrib == 'class' && $value == '' ) {
 381                                 unset( $attribs[$attrib] );
 382                         }
 383                 }
 384
 385                 // More subtle checks
 386                 if ( $element === 'link'
 387                         && isset( $attribs['type'] ) && strval( $attribs['type'] ) == 'text/css'
 388                 ) {
 389                         unset( $attribs['type'] );
 390                 }
 391                 if ( $element === 'input' ) {
 392                         $type = isset( $attribs['type'] ) ? $attribs['type'] : null;
 393                         $value = isset( $attribs['value'] ) ? $attribs['value'] : null;
 394                         if ( $type === 'checkbox' || $type === 'radio' ) {
 395                                 // The default value for checkboxes and radio buttons is 'on'
 396                                 // not ''. By stripping value="" we break radio boxes that
 397                                 // actually wants empty values.
 398                                 if ( $value === 'on' ) {
 399                                         unset( $attribs['value'] );
 400                                 }
 401                         } elseif ( $type === 'submit' ) {
 402                                 // The default value for submit appears to be "Submit" but
 403                                 // let's not bother stripping out localized text that matches
 404                                 // that.
 405                         } else {
 406                                 // The default value for nearly every other field type is ''
 407                                 // The 'range' and 'color' types use different defaults but
 408                                 // stripping a value="" does not hurt them.
 409                                 if ( $value === '' ) {
 410                                         unset( $attribs['value'] );
 411                                 }
 412                         }
 413                 }
 414                 if ( $element === 'select' && isset( $attribs['size'] ) ) {
 415                         if ( in_array( 'multiple', $attribs )
 416                                 || ( isset( $attribs['multiple'] ) && $attribs['multiple'] !== false )
 417                         ) {
 418                                 // A multi-select
 419                                 if ( strval( $attribs['size'] ) == '4' ) {
 420                                         unset( $attribs['size'] );
 421                                 }
 422                         } else {
 423                                 // Single select
 424                                 if ( strval( $attribs['size'] ) == '1' ) {
 425                                         unset( $attribs['size'] );
 426                                 }
 427                         }
 428                 }
 429
 430                 return $attribs;
 431         }
 432
 433         /**
 434          * Given an associative array of element attributes, generate a string
 435          * to stick after the element name in HTML output.  Like array( 'href' =>
 436          * 'http://www.mediawiki.org/' ) becomes something like
 437          * ' href="http://www.mediawiki.org"'.  Again, this is like
 438          * Xml::expandAttributes(), but it implements some HTML-specific logic.
 439          *
 440          * Attributes that can contain space-separated lists ('class', 'accesskey' and 'rel') array
 441          * values are allowed as well, which will automagically be normalized
 442          * and converted to a space-separated string. In addition to a numerical
 443          * array, the attribute value may also be an associative array. See the
 444          * example below for how that works.
 445          *
 446          * @par Numerical array
 447          * @code
 448          *     Html::element( 'em', array(
 449          *         'class' => array( 'foo', 'bar' )
 450          *     ) );
 451          *     // gives '<em class="foo bar"></em>'
 452          * @endcode
 453          *
 454          * @par Associative array
 455          * @code
 456          *     Html::element( 'em', array(
 457          *         'class' => array( 'foo', 'bar', 'foo' => false, 'quux' => true )
 458          *     ) );
 459          *     // gives '<em class="bar quux"></em>'
 460          * @endcode
 461          *
 462          * @param array $attribs Associative array of attributes, e.g., array(
 463          *   'href' => 'http://www.mediawiki.org/' ).  Values will be HTML-escaped.
 464          *   A value of false means to omit the attribute.  For boolean attributes,
 465          *   you can omit the key, e.g., array( 'checked' ) instead of
 466          *   array( 'checked' => 'checked' ) or such.
 467          *
 468          * @throws MWException If an attribute that doesn't allow lists is set to an array
 469          * @return string HTML fragment that goes between element name and '>'
 470          *   (starting with a space if at least one attribute is output)
 471          */
 472         public static function expandAttributes( array $attribs ) {
 473                 $ret = '';
 474                 foreach ( $attribs as $key => $value ) {
 475                         // Support intuitive array( 'checked' => true/false ) form
 476                         if ( $value === false || is_null( $value ) ) {
 477                                 continue;
 478                         }
 479
 480                         // For boolean attributes, support array( 'foo' ) instead of
 481                         // requiring array( 'foo' => 'meaningless' ).
 482                         if ( is_int( $key ) && in_array( strtolower( $value ), self::$boolAttribs ) ) {
 483                                 $key = $value;
 484                         }
 485
 486                         // Not technically required in HTML5 but we'd like consistency
 487                         // and better compression anyway.
 488                         $key = strtolower( $key );
 489
 490                         // Bug 23769: Blacklist all form validation attributes for now.  Current
 491                         // (June 2010) WebKit has no UI, so the form just refuses to submit
 492                         // without telling the user why, which is much worse than failing
 493                         // server-side validation.  Opera is the only other implementation at
 494                         // this time, and has ugly UI, so just kill the feature entirely until
 495                         // we have at least one good implementation.
 496
 497                         // As the default value of "1" for "step" rejects decimal
 498                         // numbers to be entered in 'type="number"' fields, allow
 499                         // the special case 'step="any"'.
 500
 501                         if ( in_array( $key, [ 'max', 'min', 'pattern', 'required' ] )
 502                                 || $key === 'step' && $value !== 'any' ) {
 503                                 continue;
 504                         }
 505
 506                         // http://www.w3.org/TR/html401/index/attributes.html ("space-separated")
 507                         // http://www.w3.org/TR/html5/index.html#attributes-1 ("space-separated")
 508                         $spaceSeparatedListAttributes = [
 509                                 'class', // html4, html5
 510                                 'accesskey', // as of html5, multiple space-separated values allowed
 511                                 // html4-spec doesn't document rel= as space-separated
 512                                 // but has been used like that and is now documented as such
 513                                 // in the html5-spec.
 514                                 'rel',
 515                         ];
 516
 517                         // Specific features for attributes that allow a list of space-separated values
 518                         if ( in_array( $key, $spaceSeparatedListAttributes ) ) {
 519                                 // Apply some normalization and remove duplicates
 520
 521                                 // Convert into correct array. Array can contain space-separated
 522                                 // values. Implode/explode to get those into the main array as well.
 523                                 if ( is_array( $value ) ) {
 524                                         // If input wasn't an array, we can skip this step
 525                                         $newValue = [];
 526                                         foreach ( $value as $k => $v ) {
 527                                                 if ( is_string( $v ) ) {
 528                                                         // String values should be normal `array( 'foo' )`
 529                                                         // Just append them
 530                                                         if ( !isset( $value[$v] ) ) {
 531                                                                 // As a special case don't set 'foo' if a
 532                                                                 // separate 'foo' => true/false exists in the array
 533                                                                 // keys should be authoritative
 534                                                                 $newValue[] = $v;
 535                                                         }
 536                                                 } elseif ( $v ) {
 537                                                         // If the value is truthy but not a string this is likely
 538                                                         // an array( 'foo' => true ), falsy values don't add strings
 539                                                         $newValue[] = $k;
 540                                                 }
 541                                         }
 542                                         $value = implode( ' ', $newValue );
 543                                 }
 544                                 $value = explode( ' ', $value );
 545
 546                                 // Normalize spacing by fixing up cases where people used
 547                                 // more than 1 space and/or a trailing/leading space
 548                                 $value = array_diff( $value, [ '', ' ' ] );
 549
 550                                 // Remove duplicates and create the string
 551                                 $value = implode( ' ', array_unique( $value ) );
 552                         } elseif ( is_array( $value ) ) {
 553                                 throw new MWException( "HTML attribute $key can not contain a list of values" );
 554                         }
 555
 556                         $quote = '"';
 557
 558                         if ( in_array( $key, self::$boolAttribs ) ) {
 559                                 $ret .= " $key=\"\"";
 560                         } else {
 561                                 // Apparently we need to entity-encode \n, \r, \t, although the
 562                                 // spec doesn't mention that.  Since we're doing strtr() anyway,
 563                                 // we may as well not call htmlspecialchars().
 564                                 // @todo FIXME: Verify that we actually need to
 565                                 // escape \n\r\t here, and explain why, exactly.
 566                                 // We could call Sanitizer::encodeAttribute() for this, but we
 567                                 // don't because we're stubborn and like our marginal savings on
 568                                 // byte size from not having to encode unnecessary quotes.
 569                                 // The only difference between this transform and the one by
 570                                 // Sanitizer::encodeAttribute() is ' is not encoded.
 571                                 $map = [
 572                                         '&' => '&amp;',
 573                                         '"' => '&quot;',
 574                                         '>' => '&gt;',
 575                                         // '<' allegedly allowed per spec
 576                                         // but breaks some tools if not escaped.
 577                                         "<" => '&lt;',
 578                                         "\n" => '&#10;',
 579                                         "\r" => '&#13;',
 580                                         "\t" => '&#9;'
 581                                 ];
 582                                 $ret .= " $key=$quote" . strtr( $value, $map ) . $quote;
 583                         }
 584                 }
 585                 return $ret;
 586         }
 587
 588         /**
 589          * Output a "<script>" tag with the given contents.
 590          *
 591          * @todo do some useful escaping as well, like if $contents contains
 592          * literal "</script>" or (for XML) literal "]]>".
 593          *
 594          * @param string $contents JavaScript
 595          * @return string Raw HTML
 596          */
 597         public static function inlineScript( $contents ) {
 598                 $attrs = [];
 599
 600                 if ( preg_match( '/[<&]/', $contents ) ) {
 601                         $contents = "/*<![CDATA[*/$contents/*]]>*/";
 602                 }
 603
 604                 return self::rawElement( 'script', $attrs, $contents );
 605         }
 606
 607         /**
 608          * Output a "<script>" tag linking to the given URL, e.g.,
 609          * "<script src=foo.js></script>".
 610          *
 611          * @param string $url
 612          * @return string Raw HTML
 613          */
 614         public static function linkedScript( $url ) {
 615                 $attrs = [ 'src' => $url ];
 616
 617                 return self::element( 'script', $attrs );
 618         }
 619
 620         /**
 621          * Output a "<style>" tag with the given contents for the given media type
 622          * (if any).  TODO: do some useful escaping as well, like if $contents
 623          * contains literal "</style>" (admittedly unlikely).
 624          *
 625          * @param string $contents CSS
 626          * @param string $media A media type string, like 'screen'
 627          * @return string Raw HTML
 628          */
 629         public static function inlineStyle( $contents, $media = 'all' ) {
 630                 if ( preg_match( '/[<&]/', $contents ) ) {
 631                         $contents = "/*<![CDATA[*/$contents/*]]>*/";
 632                 }
 633
 634                 return self::rawElement( 'style', [
 635                         'media' => $media,
 636                 ], $contents );
 637         }
 638
 639         /**
 640          * Output a "<link rel=stylesheet>" linking to the given URL for the given
 641          * media type (if any).
 642          *
 643          * @param string $url
 644          * @param string $media A media type string, like 'screen'
 645          * @return string Raw HTML
 646          */
 647         public static function linkedStyle( $url, $media = 'all' ) {
 648                 return self::element( 'link', [
 649                         'rel' => 'stylesheet',
 650                         'href' => $url,
 651                         'media' => $media,
 652                 ] );
 653         }
 654
 655         /**
 656          * Convenience function to produce an "<input>" element.  This supports the
 657          * new HTML5 input types and attributes.
 658          *
 659          * @param string $name Name attribute
 660          * @param string $value Value attribute
 661          * @param string $type Type attribute
 662          * @param array $attribs Associative array of miscellaneous extra
 663          *   attributes, passed to Html::element()
 664          * @return string Raw HTML
 665          */
 666         public static function input( $name, $value = '', $type = 'text', array $attribs = [] ) {
 667                 $attribs['type'] = $type;
 668                 $attribs['value'] = $value;
 669                 $attribs['name'] = $name;
 670                 if ( in_array( $type, [ 'text', 'search', 'email', 'password', 'number' ] ) ) {
 671                         $attribs = self::getTextInputAttributes( $attribs );
 672                 }
 673                 if ( in_array( $type, [ 'button', 'reset', 'submit' ] ) ) {
 674                         $attribs = self::buttonAttributes( $attribs );
 675                 }
 676                 return self::element( 'input', $attribs );
 677         }
 678
 679         /**
 680          * Convenience function to produce a checkbox (input element with type=checkbox)
 681          *
 682          * @param string $name Name attribute
 683          * @param bool $checked Whether the checkbox is checked or not
 684          * @param array $attribs Array of additional attributes
 685          * @return string Raw HTML
 686          */
 687         public static function check( $name, $checked = false, array $attribs = [] ) {
 688                 if ( isset( $attribs['value'] ) ) {
 689                         $value = $attribs['value'];
 690                         unset( $attribs['value'] );
 691                 } else {
 692                         $value = 1;
 693                 }
 694
 695                 if ( $checked ) {
 696                         $attribs[] = 'checked';
 697                 }
 698
 699                 return self::input( $name, $value, 'checkbox', $attribs );
 700         }
 701
 702         /**
 703          * Convenience function to produce a radio button (input element with type=radio)
 704          *
 705          * @param string $name Name attribute
 706          * @param bool $checked Whether the radio button is checked or not
 707          * @param array $attribs Array of additional attributes
 708          * @return string Raw HTML
 709          */
 710         public static function radio( $name, $checked = false, array $attribs = [] ) {
 711                 if ( isset( $attribs['value'] ) ) {
 712                         $value = $attribs['value'];
 713                         unset( $attribs['value'] );
 714                 } else {
 715                         $value = 1;
 716                 }
 717
 718                 if ( $checked ) {
 719                         $attribs[] = 'checked';
 720                 }
 721
 722                 return self::input( $name, $value, 'radio', $attribs );
 723         }
 724
 725         /**
 726          * Convenience function for generating a label for inputs.
 727          *
 728          * @param string $label Contents of the label
 729          * @param string $id ID of the element being labeled
 730          * @param array $attribs Additional attributes
 731          * @return string Raw HTML
 732          */
 733         public static function label( $label, $id, array $attribs = [] ) {
 734                 $attribs += [
 735                         'for' => $id
 736                 ];
 737                 return self::element( 'label', $attribs, $label );
 738         }
 739
 740         /**
 741          * Convenience function to produce an input element with type=hidden
 742          *
 743          * @param string $name Name attribute
 744          * @param string $value Value attribute
 745          * @param array $attribs Associative array of miscellaneous extra
 746          *   attributes, passed to Html::element()
 747          * @return string Raw HTML
 748          */
 749         public static function hidden( $name, $value, array $attribs = [] ) {
 750                 return self::input( $name, $value, 'hidden', $attribs );
 751         }
 752
 753         /**
 754          * Convenience function to produce a <textarea> element.
 755          *
 756          * This supports leaving out the cols= and rows= which Xml requires and are
 757          * required by HTML4/XHTML but not required by HTML5.
 758          *
 759          * @param string $name Name attribute
 760          * @param string $value Value attribute
 761          * @param array $attribs Associative array of miscellaneous extra
 762          *   attributes, passed to Html::element()
 763          * @return string Raw HTML
 764          */
 765         public static function textarea( $name, $value = '', array $attribs = [] ) {
 766                 $attribs['name'] = $name;
 767
 768                 if ( substr( $value, 0, 1 ) == "\n" ) {
 769                         // Workaround for bug 12130: browsers eat the initial newline
 770                         // assuming that it's just for show, but they do keep the later
 771                         // newlines, which we may want to preserve during editing.
 772                         // Prepending a single newline
 773                         $spacedValue = "\n" . $value;
 774                 } else {
 775                         $spacedValue = $value;
 776                 }
 777                 return self::element( 'textarea', self::getTextInputAttributes( $attribs ), $spacedValue );
 778         }
 779
 780         /**
 781          * Helper for Html::namespaceSelector().
 782          * @param array $params See Html::namespaceSelector()
 783          * @return array
 784          */
 785         public static function namespaceSelectorOptions( array $params = [] ) {
 786                 global $wgContLang;
 787
 788                 $options = [];
 789
 790                 if ( !isset( $params['exclude'] ) || !is_array( $params['exclude'] ) ) {
 791                         $params['exclude'] = [];
 792                 }
 793
 794                 if ( isset( $params['all'] ) ) {
 795                         // add an option that would let the user select all namespaces.
 796                         // Value is provided by user, the name shown is localized for the user.
 797                         $options[$params['all']] = wfMessage( 'namespacesall' )->text();
 798                 }
 799                 // Add all namespaces as options (in the content language)
 800                 $options += $wgContLang->getFormattedNamespaces();
 801
 802                 $optionsOut = [];
 803                 // Filter out namespaces below 0 and massage labels
 804                 foreach ( $options as $nsId => $nsName ) {
 805                         if ( $nsId < NS_MAIN || in_array( $nsId, $params['exclude'] ) ) {
 806                                 continue;
 807                         }
 808                         if ( $nsId === NS_MAIN ) {
 809                                 // For other namespaces use the namespace prefix as label, but for
 810                                 // main we don't use "" but the user message describing it (e.g. "(Main)" or "(Article)")
 811                                 $nsName = wfMessage( 'blanknamespace' )->text();
 812                         } elseif ( is_int( $nsId ) ) {
 813                                 $nsName = $wgContLang->convertNamespace( $nsId );
 814                         }
 815                         $optionsOut[$nsId] = $nsName;
 816                 }
 817
 818                 return $optionsOut;
 819         }
 820
 821         /**
 822          * Build a drop-down box for selecting a namespace
 823          *
 824          * @param array $params Params to set.
 825          * - selected: [optional] Id of namespace which should be pre-selected
 826          * - all: [optional] Value of item for "all namespaces". If null or unset,
 827          *   no "<option>" is generated to select all namespaces.
 828          * - label: text for label to add before the field.
 829          * - exclude: [optional] Array of namespace ids to exclude.
 830          * - disable: [optional] Array of namespace ids for which the option should
 831          *   be disabled in the selector.
 832          * @param array $selectAttribs HTML attributes for the generated select element.
 833          * - id:   [optional], default: 'namespace'.
 834          * - name: [optional], default: 'namespace'.
 835          * @return string HTML code to select a namespace.
 836          */
 837         public static function namespaceSelector( array $params = [],
 838                 array $selectAttribs = []
 839         ) {
 840                 ksort( $selectAttribs );
 841
 842                 // Is a namespace selected?
 843                 if ( isset( $params['selected'] ) ) {
 844                         // If string only contains digits, convert to clean int. Selected could also
 845                         // be "all" or "" etc. which needs to be left untouched.
 846                         // PHP is_numeric() has issues with large strings, PHP ctype_digit has other issues
 847                         // and returns false for already clean ints. Use regex instead..
 848                         if ( preg_match( '/^\d+$/', $params['selected'] ) ) {
 849                                 $params['selected'] = intval( $params['selected'] );
 850                         }
 851                         // else: leaves it untouched for later processing
 852                 } else {
 853                         $params['selected'] = '';
 854                 }
 855
 856                 if ( !isset( $params['disable'] ) || !is_array( $params['disable'] ) ) {
 857                         $params['disable'] = [];
 858                 }
 859
 860                 // Associative array between option-values and option-labels
 861                 $options = self::namespaceSelectorOptions( $params );
 862
 863                 // Convert $options to HTML
 864                 $optionsHtml = [];
 865                 foreach ( $options as $nsId => $nsName ) {
 866                         $optionsHtml[] = self::element(
 867                                 'option', [
 868                                         'disabled' => in_array( $nsId, $params['disable'] ),
 869                                         'value' => $nsId,
 870                                         'selected' => $nsId === $params['selected'],
 871                                 ], $nsName
 872                         );
 873                 }
 874
 875                 if ( !array_key_exists( 'id', $selectAttribs ) ) {
 876                         $selectAttribs['id'] = 'namespace';
 877                 }
 878
 879                 if ( !array_key_exists( 'name', $selectAttribs ) ) {
 880                         $selectAttribs['name'] = 'namespace';
 881                 }
 882
 883                 $ret = '';
 884                 if ( isset( $params['label'] ) ) {
 885                         $ret .= self::element(
 886                                 'label', [
 887                                         'for' => isset( $selectAttribs['id'] ) ? $selectAttribs['id'] : null,
 888                                 ], $params['label']
 889                         ) . '&#160;';
 890                 }
 891
 892                 // Wrap options in a <select>
 893                 $ret .= self::openElement( 'select', $selectAttribs )
 894                         . "\n"
 895                         . implode( "\n", $optionsHtml )
 896                         . "\n"
 897                         . self::closeElement( 'select' );
 898
 899                 return $ret;
 900         }
 901
 902         /**
 903          * Constructs the opening html-tag with necessary doctypes depending on
 904          * global variables.
 905          *
 906          * @param array $attribs Associative array of miscellaneous extra
 907          *   attributes, passed to Html::element() of html tag.
 908          * @return string Raw HTML
 909          */
 910         public static function htmlHeader( array $attribs = [] ) {
 911                 $ret = '';
 912
 913                 global $wgHtml5Version, $wgMimeType, $wgXhtmlNamespaces;
 914
 915                 $isXHTML = self::isXmlMimeType( $wgMimeType );
 916
 917                 if ( $isXHTML ) { // XHTML5
 918                         // XML MIME-typed markup should have an xml header.
 919                         // However a DOCTYPE is not needed.
 920                         $ret .= "<?xml version=\"1.0\" encoding=\"UTF-8\" ?" . ">\n";
 921
 922                         // Add the standard xmlns
 923                         $attribs['xmlns'] = 'http://www.w3.org/1999/xhtml';
 924
 925                         // And support custom namespaces
 926                         foreach ( $wgXhtmlNamespaces as $tag => $ns ) {
 927                                 $attribs["xmlns:$tag"] = $ns;
 928                         }
 929                 } else { // HTML5
 930                         // DOCTYPE
 931                         $ret .= "<!DOCTYPE html>\n";
 932                 }
 933
 934                 if ( $wgHtml5Version ) {
 935                         $attribs['version'] = $wgHtml5Version;
 936                 }
 937
 938                 $ret .= self::openElement( 'html', $attribs );
 939
 940                 return $ret;
 941         }
 942
 943         /**
 944          * Determines if the given MIME type is xml.
 945          *
 946          * @param string $mimetype MIME type
 947          * @return bool
 948          */
 949         public static function isXmlMimeType( $mimetype ) {
 950                 # http://www.whatwg.org/html/infrastructure.html#xml-mime-type
 951                 # * text/xml
 952                 # * application/xml
 953                 # * Any MIME type with a subtype ending in +xml (this implicitly includes application/xhtml+xml)
 954                 return (bool)preg_match( '!^(text|application)/xml$|^.+/.+\+xml$!', $mimetype );
 955         }
 956
 957         /**
 958          * Get HTML for an info box with an icon.
 959          *
 960          * @param string $text Wikitext, get this with wfMessage()->plain()
 961          * @param string $icon Path to icon file (used as 'src' attribute)
 962          * @param string $alt Alternate text for the icon
 963          * @param string $class Additional class name to add to the wrapper div
 964          *
 965          * @return string
 966          */
 967         static function infoBox( $text, $icon, $alt, $class = '' ) {
 968                 $s = self::openElement( 'div', [ 'class' => "mw-infobox $class" ] );
 969
 970                 $s .= self::openElement( 'div', [ 'class' => 'mw-infobox-left' ] ) .
 971                                 self::element( 'img',
 972                                         [
 973                                                 'src' => $icon,
 974                                                 'alt' => $alt,
 975                                         ]
 976                                 ) .
 977                                 self::closeElement( 'div' );
 978
 979                 $s .= self::openElement( 'div', [ 'class' => 'mw-infobox-right' ] ) .
 980                                 $text .
 981                                 self::closeElement( 'div' );
 982                 $s .= self::element( 'div', [ 'style' => 'clear: left;' ], ' ' );
 983
 984                 $s .= self::closeElement( 'div' );
 985
 986                 $s .= self::element( 'div', [ 'style' => 'clear: left;' ], ' ' );
 987
 988                 return $s;
 989         }
 990
 991         /**
 992          * Generate a srcset attribute value.
 993          *
 994          * Generates a srcset attribute value from an array mapping pixel densities
 995          * to URLs. A trailing 'x' in pixel density values is optional.
 996          *
 997          * @note srcset width and height values are not supported.
 998          *
 999          * @see http://www.whatwg.org/html/embedded-content-1.html#attr-img-srcset
1000          *
1001          * @par Example:
1002          * @code
1003          *     Html::srcSet( array(
1004          *         '1x'   => 'standard.jpeg',
1005          *         '1.5x' => 'large.jpeg',
1006          *         '3x'   => 'extra-large.jpeg',
1007          *     ) );
1008          *     // gives 'standard.jpeg 1x, large.jpeg 1.5x, extra-large.jpeg 2x'
1009          * @endcode
1010          *
1011          * @param string[] $urls
1012          * @return string
1013          */
1014         static function srcSet( array $urls ) {
1015                 $candidates = [];
1016                 foreach ( $urls as $density => $url ) {
1017                         // Cast density to float to strip 'x', then back to string to serve
1018                         // as array index.
1019                         $density = (string)(float)$density;
1020                         $candidates[$density] = $url;
1021                 }
1022
1023                 // Remove duplicates that are the same as a smaller value
1024                 ksort( $candidates, SORT_NUMERIC );
1025                 $candidates = array_unique( $candidates );
1026
1027                 // Append density info to the url
1028                 foreach ( $candidates as $density => $url ) {
1029                         $candidates[$density] = $url . ' ' . $density . 'x';
1030                 }
1031
1032                 return implode( ", ", $candidates );
1033         }
1034 }