elements. */ class Html { # List of void elements from HTML5, section 9.1.2 as of 2009-08-10 private static $voidElements = array( 'area', 'base', 'br', 'col', 'command', 'embed', 'hr', 'img', 'input', 'keygen', 'link', 'meta', 'param', 'source', ); # Boolean attributes, which may have the value omitted entirely. Manually # collected from the HTML5 spec as of 2009-08-10. private static $boolAttribs = array( 'async', 'autobuffer', 'autofocus', 'autoplay', 'checked', 'controls', 'defer', 'disabled', 'formnovalidate', 'hidden', 'ismap', 'loop', 'multiple', 'novalidate', 'open', 'readonly', 'required', 'reversed', 'scoped', 'seamless', ); /** * Returns an HTML element in a string. The major advantage here over * manually typing out the HTML is that it will escape all attribute * values. If you're hardcoding all the attributes, or there are none, you * should probably type out the string yourself. * * This is quite similar to Xml::tags(), but it implements some useful * HTML-specific logic. For instance, there is no $allowShortTag * parameter: the closing tag is magically omitted if $element has an empty * content model. If $wgWellFormedXml is false, then a few bytes will be * shaved off the HTML output as well. In the future, other HTML-specific * features might be added, like allowing arrays for the values of * attributes like class= and media=. * * @param $element string The element's name, e.g., 'a' * @param $attribs array Associative array of attributes, e.g., array( * 'href' => 'http://www.mediawiki.org/' ). See expandAttributes() for * further documentation. * @param $contents string The raw HTML contents of the element: *not* * escaped! * @return string Raw HTML */ public static function rawElement( $element, $attribs = array(), $contents = '' ) { global $wgWellFormedXml; $start = self::openElement( $element, $attribs ); if ( in_array( $element, self::$voidElements ) ) { if ( $wgWellFormedXml ) { # Silly XML. return substr( $start, 0, -1 ) . ' />'; } return $start; } else { return "$start$contents"; } } /** * Identical to rawElement(), but HTML-escapes $contents (like * Xml::element()). */ public static function element( $element, $attribs = array(), $contents = '' ) { return self::rawElement( $element, $attribs, strtr( $contents, array( # There's no point in escaping quotes, >, etc. in the contents of # elements. '&' => '&', '<' => '<' ) ) ); } /** * Identical to rawElement(), but has no third parameter and omits the end * tag (and the self-closing / in XML mode for empty elements). */ public static function openElement( $element, $attribs = array() ) { global $wgHtml5; $attribs = (array)$attribs; # This is not required in HTML5, but let's do it anyway, for # consistency and better compression. $element = strtolower( $element ); # Remove HTML5-only attributes if we aren't doing HTML5, and disable # form validation regardless (see bug 23769 and the more detailed # comment in expandAttributes()) if ( $element == 'input' ) { # Whitelist of types that don't cause validation. All except # 'search' are valid in XHTML1. $validTypes = array( 'hidden', 'text', 'password', 'checkbox', 'radio', 'file', 'submit', 'image', 'reset', 'button', 'search', ); if ( isset( $attribs['type'] ) && !in_array( $attribs['type'], $validTypes ) ) { unset( $attribs['type'] ); } if ( isset( $attribs['type'] ) && $attribs['type'] == 'search' && !$wgHtml5 ) { unset( $attribs['type'] ); } # Here we're blacklisting some HTML5-only attributes... $html5attribs = array( 'autocomplete', 'autofocus', 'max', 'min', 'multiple', 'pattern', 'placeholder', 'required', 'step', 'spellcheck', ); foreach ( $html5attribs as $badAttr ) { unset( $attribs[$badAttr] ); } } if ( !$wgHtml5 && $element == 'textarea' && isset( $attribs['maxlength'] ) ) { unset( $attribs['maxlength'] ); } return "<$element" . self::expandAttributes( self::dropDefaults( $element, $attribs ) ) . '>'; } /** * Given an element name and an associative array of element attributes, * return an array that is functionally identical to the input array, but * possibly smaller. In particular, attributes might be stripped if they * are given their default values. * * This method is not guaranteed to remove all redundant attributes, only * some common ones and some others selected arbitrarily at random. It * only guarantees that the output array should be functionally identical * to the input array (currently per the HTML 5 draft as of 2009-09-06). * * @param $element string Name of the element, e.g., 'a' * @param $attribs array Associative array of attributes, e.g., array( * 'href' => 'http://www.mediawiki.org/' ). See expandAttributes() for * further documentation. * @return array An array of attributes functionally identical to $attribs */ private static function dropDefaults( $element, $attribs ) { # Don't bother doing anything if we aren't outputting HTML5; it's too # much of a pain to maintain two sets of defaults. global $wgHtml5; if ( !$wgHtml5 ) { return $attribs; } static $attribDefaults = array( 'area' => array( 'shape' => 'rect' ), 'button' => array( 'formaction' => 'GET', 'formenctype' => 'application/x-www-form-urlencoded', 'type' => 'submit', ), 'canvas' => array( 'height' => '150', 'width' => '300', ), 'command' => array( 'type' => 'command' ), 'form' => array( 'action' => 'GET', 'autocomplete' => 'on', 'enctype' => 'application/x-www-form-urlencoded', ), 'input' => array( 'formaction' => 'GET', 'type' => 'text', 'value' => '', ), 'keygen' => array( 'keytype' => 'rsa' ), 'link' => array( 'media' => 'all' ), 'menu' => array( 'type' => 'list' ), # Note: the use of text/javascript here instead of other JavaScript # MIME types follows the HTML5 spec. 'script' => array( 'type' => 'text/javascript' ), 'style' => array( 'media' => 'all', 'type' => 'text/css', ), 'textarea' => array( 'wrap' => 'soft' ), ); $element = strtolower( $element ); foreach ( $attribs as $attrib => $value ) { $lcattrib = strtolower( $attrib ); $value = strval( $value ); # Simple checks using $attribDefaults if ( isset( $attribDefaults[$element][$lcattrib] ) && $attribDefaults[$element][$lcattrib] == $value ) { unset( $attribs[$attrib] ); } if ( $lcattrib == 'class' && $value == '' ) { unset( $attribs[$attrib] ); } } # More subtle checks if ( $element === 'link' && isset( $attribs['type'] ) && strval( $attribs['type'] ) == 'text/css' ) { unset( $attribs['type'] ); } if ( $element === 'select' && isset( $attribs['size'] ) ) { if ( in_array( 'multiple', $attribs ) || ( isset( $attribs['multiple'] ) && $attribs['multiple'] !== false ) ) { # A multi-select if ( strval( $attribs['size'] ) == '4' ) { unset( $attribs['size'] ); } } else { # Single select if ( strval( $attribs['size'] ) == '1' ) { unset( $attribs['size'] ); } } } return $attribs; } /** * Given an associative array of element attributes, generate a string * to stick after the element name in HTML output. Like array( 'href' => * 'http://www.mediawiki.org/' ) becomes something like * ' href="http://www.mediawiki.org"'. Again, this is like * Xml::expandAttributes(), but it implements some HTML-specific logic. * For instance, it will omit quotation marks if $wgWellFormedXml is false, * and will treat boolean attributes specially. * * @param $attribs array Associative array of attributes, e.g., array( * 'href' => 'http://www.mediawiki.org/' ). Values will be HTML-escaped. * A value of false means to omit the attribute. For boolean attributes, * you can omit the key, e.g., array( 'checked' ) instead of * array( 'checked' => 'checked' ) or such. * @return string HTML fragment that goes between element name and '>' * (starting with a space if at least one attribute is output) */ public static function expandAttributes( $attribs ) { global $wgHtml5, $wgWellFormedXml; $ret = ''; $attribs = (array)$attribs; foreach ( $attribs as $key => $value ) { if ( $value === false ) { continue; } # For boolean attributes, support array( 'foo' ) instead of # requiring array( 'foo' => 'meaningless' ). if ( is_int( $key ) && in_array( strtolower( $value ), self::$boolAttribs ) ) { $key = $value; } # Not technically required in HTML5, but required in XHTML 1.0, # and we'd like consistency and better compression anyway. $key = strtolower( $key ); # Bug 23769: Blacklist all form validation attributes for now. Current # (June 2010) WebKit has no UI, so the form just refuses to submit # without telling the user why, which is much worse than failing # server-side validation. Opera is the only other implementation at # this time, and has ugly UI, so just kill the feature entirely until # we have at least one good implementation. if ( in_array( $key, array( 'max', 'min', 'pattern', 'required', 'step' ) ) ) { continue; } # See the "Attributes" section in the HTML syntax part of HTML5, # 9.1.2.3 as of 2009-08-10. Most attributes can have quotation # marks omitted, but not all. (Although a literal " is not # permitted, we don't check for that, since it will be escaped # anyway.) # # See also research done on further characters that need to be # escaped: http://code.google.com/p/html5lib/issues/detail?id=93 $badChars = "\\x00- '=<>`/\x{00a0}\x{1680}\x{180e}\x{180F}\x{2000}\x{2001}" . "\x{2002}\x{2003}\x{2004}\x{2005}\x{2006}\x{2007}\x{2008}\x{2009}" . "\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}"; if ( $wgWellFormedXml || $value === '' || preg_match( "![$badChars]!u", $value ) ) { $quote = '"'; } else { $quote = ''; } if ( in_array( $key, self::$boolAttribs ) ) { # In XHTML 1.0 Transitional, the value needs to be equal to the # key. In HTML5, we can leave the value empty instead. If we # don't need well-formed XML, we can omit the = entirely. if ( !$wgWellFormedXml ) { $ret .= " $key"; } elseif ( $wgHtml5 ) { $ret .= " $key=\"\""; } else { $ret .= " $key=\"$key\""; } } else { # Apparently we need to entity-encode \n, \r, \t, although the # spec doesn't mention that. Since we're doing strtr() anyway, # and we don't need <> escaped here, we may as well not call # htmlspecialchars(). FIXME: verify that we actually need to # escape \n\r\t here, and explain why, exactly. # # We could call Sanitizer::encodeAttribute() for this, but we # don't because we're stubborn and like our marginal savings on # byte size from not having to encode unnecessary quotes. $map = array( '&' => '&', '"' => '"', "\n" => ' ', "\r" => ' ', "\t" => ' ' ); if ( $wgWellFormedXml ) { # This is allowed per spec: # But reportedly it breaks some XML tools? FIXME: is this # really true? $map['<'] = '<'; } $ret .= " $key=$quote" . strtr( $value, $map ) . $quote; } } return $ret; } /** * Output a ' or (for * XML) literal "]]>". * * @param $contents string JavaScript * @return string Raw HTML */ public static function inlineScript( $contents ) { global $wgHtml5, $wgJsMimeType, $wgWellFormedXml; $attrs = array(); if ( !$wgHtml5 ) { $attrs['type'] = $wgJsMimeType; } if ( $wgWellFormedXml && preg_match( '/[<&]/', $contents ) ) { $contents = "/**/"; } return self::rawElement( 'script', $attrs, $contents ); } /** * Output a . * * @param $url string * @return string Raw HTML */ public static function linkedScript( $url ) { global $wgHtml5, $wgJsMimeType; $attrs = array( 'src' => $url ); if ( !$wgHtml5 ) { $attrs['type'] = $wgJsMimeType; } return self::element( 'script', $attrs ); } /** * Output a ' (admittedly unlikely). * * @param $contents string CSS * @param $media mixed A media type string, like 'screen' * @return string Raw HTML */ public static function inlineStyle( $contents, $media = 'all' ) { global $wgWellFormedXml; if ( $wgWellFormedXml && preg_match( '/[<&]/', $contents ) ) { $contents = "/**/"; } return self::rawElement( 'style', array( 'type' => 'text/css', 'media' => $media, ), $contents ); } /** * Output a linking to the given URL for the given * media type (if any). * * @param $url string * @param $media mixed A media type string, like 'screen' * @return string Raw HTML */ public static function linkedStyle( $url, $media = 'all' ) { return self::element( 'link', array( 'rel' => 'stylesheet', 'href' => $url, 'type' => 'text/css', 'media' => $media, ) ); } /** * Convenience function to produce an element. This supports the * new HTML5 input types and attributes, and will silently strip them if * $wgHtml5 is false. * * @param $name string name attribute * @param $value mixed value attribute * @param $type string type attribute * @param $attribs array Associative array of miscellaneous extra * attributes, passed to Html::element() * @return string Raw HTML */ public static function input( $name, $value = '', $type = 'text', $attribs = array() ) { $attribs['type'] = $type; $attribs['value'] = $value; $attribs['name'] = $name; return self::element( 'input', $attribs ); } /** * Convenience function to produce an input element with type=hidden, like * Xml::hidden. * * @param $name string name attribute * @param $value string value attribute * @param $attribs array Associative array of miscellaneous extra * attributes, passed to Html::element() * @return string Raw HTML */ public static function hidden( $name, $value, $attribs = array() ) { return self::input( $name, $value, 'hidden', $attribs ); } /** * Convenience function to produce an element. This supports leaving * out the cols= and rows= which Xml requires and are required by HTML4/XHTML * but not required by HTML5 and will silently set cols="" and rows="" if * $wgHtml5 is false and cols and rows are omitted (HTML4 validates present * but empty cols="" and rows="" as valid). * * @param $name string name attribute * @param $value string value attribute * @param $attribs array Associative array of miscellaneous extra * attributes, passed to Html::element() * @return string Raw HTML */ public static function textarea( $name, $value = '', $attribs = array() ) { global $wgHtml5; $attribs['name'] = $name; if ( !$wgHtml5 ) { if ( !isset( $attribs['cols'] ) ) $attribs['cols'] = ""; if ( !isset( $attribs['rows'] ) ) $attribs['rows'] = ""; } return self::element( 'textarea', $attribs, $value ); } }