X-Git-Url: https://scripts.mit.edu/gitweb/autoinstalls/wordpress.git/blobdiff_plain/8a06f4f9392d1ac373442f82ee40428a3cb81395..refs/tags/wordpress-3.3.1-scripts:/wp-includes/kses.php
diff --git a/wp-includes/kses.php b/wp-includes/kses.php
index c7538b98..d76b3448 100644
--- a/wp-includes/kses.php
+++ b/wp-includes/kses.php
@@ -1,43 +1,50 @@
+ * @author Ulf Harnhammar
*
* @package External
* @subpackage KSES
*
- * @internal
- * *** CONTACT INFORMATION ***
- * E-mail: metaur at users dot sourceforge dot net
- * Web page: http://sourceforge.net/projects/kses
- * Paper mail: Ulf Harnhammar
- * Ymergatan 17 C
- * 753 25 Uppsala
- * SWEDEN
- *
- * [kses strips evil scripts!]
*/
/**
- * You can override this in your my-hacks.php file
- * You can also override this in a plugin file. The
- * my-hacks.php is deprecated in its usage.
+ * You can override this in a plugin.
*
* @since 1.2.0
*/
-if (!defined('CUSTOM_TAGS'))
- define('CUSTOM_TAGS', false);
+if ( ! defined( 'CUSTOM_TAGS' ) )
+ define( 'CUSTOM_TAGS', false );
-if (!CUSTOM_TAGS) {
+if ( ! CUSTOM_TAGS ) {
/**
- * Kses global for default allowable HTML tags
+ * Kses global for default allowable HTML tags.
+ *
+ * Can be override by using CUSTOM_TAGS constant.
*
- * Can be override by using CUSTOM_TAGS constant
* @global array $allowedposttags
* @since 2.0.0
*/
@@ -57,6 +64,22 @@ if (!CUSTOM_TAGS) {
'title' => array ()),
'acronym' => array(
'title' => array ()),
+ 'article' => array(
+ 'align' => array (),
+ 'class' => array (),
+ 'dir' => array (),
+ 'lang' => array(),
+ 'style' => array (),
+ 'xml:lang' => array(),
+ ),
+ 'aside' => array(
+ 'align' => array (),
+ 'class' => array (),
+ 'dir' => array (),
+ 'lang' => array(),
+ 'style' => array (),
+ 'xml:lang' => array(),
+ ),
'b' => array(),
'big' => array(),
'blockquote' => array(
@@ -94,6 +117,15 @@ if (!CUSTOM_TAGS) {
'del' => array(
'datetime' => array ()),
'dd' => array(),
+ 'details' => array(
+ 'align' => array (),
+ 'class' => array (),
+ 'dir' => array (),
+ 'lang' => array(),
+ 'open' => array (),
+ 'style' => array (),
+ 'xml:lang' => array(),
+ ),
'div' => array(
'align' => array (),
'class' => array (),
@@ -105,10 +137,34 @@ if (!CUSTOM_TAGS) {
'dt' => array(),
'em' => array(),
'fieldset' => array(),
+ 'figure' => array(
+ 'align' => array (),
+ 'class' => array (),
+ 'dir' => array (),
+ 'lang' => array(),
+ 'style' => array (),
+ 'xml:lang' => array(),
+ ),
+ 'figcaption' => array(
+ 'align' => array (),
+ 'class' => array (),
+ 'dir' => array (),
+ 'lang' => array(),
+ 'style' => array (),
+ 'xml:lang' => array(),
+ ),
'font' => array(
'color' => array (),
'face' => array (),
'size' => array ()),
+ 'footer' => array(
+ 'align' => array (),
+ 'class' => array (),
+ 'dir' => array (),
+ 'lang' => array(),
+ 'style' => array (),
+ 'xml:lang' => array(),
+ ),
'form' => array(
'action' => array (),
'accept' => array (),
@@ -119,23 +175,51 @@ if (!CUSTOM_TAGS) {
'target' => array ()),
'h1' => array(
'align' => array (),
- 'class' => array ()),
- 'h2' => array(
+ 'class' => array (),
+ 'id' => array (),
+ 'style' => array ()),
+ 'h2' => array (
'align' => array (),
- 'class' => array ()),
- 'h3' => array(
+ 'class' => array (),
+ 'id' => array (),
+ 'style' => array ()),
+ 'h3' => array (
'align' => array (),
- 'class' => array ()),
- 'h4' => array(
+ 'class' => array (),
+ 'id' => array (),
+ 'style' => array ()),
+ 'h4' => array (
'align' => array (),
- 'class' => array ()),
- 'h5' => array(
+ 'class' => array (),
+ 'id' => array (),
+ 'style' => array ()),
+ 'h5' => array (
'align' => array (),
- 'class' => array ()),
- 'h6' => array(
+ 'class' => array (),
+ 'id' => array (),
+ 'style' => array ()),
+ 'h6' => array (
'align' => array (),
- 'class' => array ()),
- 'hr' => array(
+ 'class' => array (),
+ 'id' => array (),
+ 'style' => array ()),
+ 'header' => array(
+ 'align' => array (),
+ 'class' => array (),
+ 'dir' => array (),
+ 'lang' => array(),
+ 'style' => array (),
+ 'xml:lang' => array(),
+ ),
+ 'hgroup' => array(
+ 'align' => array (),
+ 'class' => array (),
+ 'dir' => array (),
+ 'lang' => array(),
+ 'style' => array (),
+ 'xml:lang' => array(),
+ ),
+ 'hr' => array (
'align' => array (),
'class' => array (),
'noshade' => array (),
@@ -165,6 +249,18 @@ if (!CUSTOM_TAGS) {
'li' => array (
'align' => array (),
'class' => array ()),
+ 'menu' => array (
+ 'class' => array (),
+ 'style' => array (),
+ 'type' => array ()),
+ 'nav' => array(
+ 'align' => array (),
+ 'class' => array (),
+ 'dir' => array (),
+ 'lang' => array(),
+ 'style' => array (),
+ 'xml:lang' => array(),
+ ),
'p' => array(
'class' => array (),
'align' => array (),
@@ -186,9 +282,25 @@ if (!CUSTOM_TAGS) {
'style' => array (),
'title' => array (),
'xml:lang' => array()),
+ 'section' => array(
+ 'align' => array (),
+ 'class' => array (),
+ 'dir' => array (),
+ 'lang' => array(),
+ 'style' => array (),
+ 'xml:lang' => array(),
+ ),
'strike' => array(),
'strong' => array(),
'sub' => array(),
+ 'summary' => array(
+ 'align' => array (),
+ 'class' => array (),
+ 'dir' => array (),
+ 'lang' => array(),
+ 'style' => array (),
+ 'xml:lang' => array(),
+ ),
'sup' => array(),
'table' => array(
'align' => array (),
@@ -273,16 +385,17 @@ if (!CUSTOM_TAGS) {
'u' => array(),
'ul' => array (
'class' => array (),
- 'style' => array (),
+ 'style' => array (),
'type' => array ()),
'ol' => array (
'class' => array (),
'start' => array (),
- 'style' => array (),
+ 'style' => array (),
'type' => array ()),
'var' => array ());
+
/**
- * Kses allowed HTML elements
+ * Kses allowed HTML elements.
*
* @global array $allowedtags
* @since 1.0.0
@@ -320,20 +433,64 @@ if (!CUSTOM_TAGS) {
// 'u' => array(),
// 'ul' => array(),
);
+
+ $allowedentitynames = array(
+ 'nbsp', 'iexcl', 'cent', 'pound', 'curren', 'yen',
+ 'brvbar', 'sect', 'uml', 'copy', 'ordf', 'laquo',
+ 'not', 'shy', 'reg', 'macr', 'deg', 'plusmn',
+ 'acute', 'micro', 'para', 'middot', 'cedil', 'ordm',
+ 'raquo', 'iquest', 'Agrave', 'Aacute', 'Acirc', 'Atilde',
+ 'Auml', 'Aring', 'AElig', 'Ccedil', 'Egrave', 'Eacute',
+ 'Ecirc', 'Euml', 'Igrave', 'Iacute', 'Icirc', 'Iuml',
+ 'ETH', 'Ntilde', 'Ograve', 'Oacute', 'Ocirc', 'Otilde',
+ 'Ouml', 'times', 'Oslash', 'Ugrave', 'Uacute', 'Ucirc',
+ 'Uuml', 'Yacute', 'THORN', 'szlig', 'agrave', 'aacute',
+ 'acirc', 'atilde', 'auml', 'aring', 'aelig', 'ccedil',
+ 'egrave', 'eacute', 'ecirc', 'euml', 'igrave', 'iacute',
+ 'icirc', 'iuml', 'eth', 'ntilde', 'ograve', 'oacute',
+ 'ocirc', 'otilde', 'ouml', 'divide', 'oslash', 'ugrave',
+ 'uacute', 'ucirc', 'uuml', 'yacute', 'thorn', 'yuml',
+ 'quot', 'amp', 'lt', 'gt', 'apos', 'OElig',
+ 'oelig', 'Scaron', 'scaron', 'Yuml', 'circ', 'tilde',
+ 'ensp', 'emsp', 'thinsp', 'zwnj', 'zwj', 'lrm',
+ 'rlm', 'ndash', 'mdash', 'lsquo', 'rsquo', 'sbquo',
+ 'ldquo', 'rdquo', 'bdquo', 'dagger', 'Dagger', 'permil',
+ 'lsaquo', 'rsaquo', 'euro', 'fnof', 'Alpha', 'Beta',
+ 'Gamma', 'Delta', 'Epsilon', 'Zeta', 'Eta', 'Theta',
+ 'Iota', 'Kappa', 'Lambda', 'Mu', 'Nu', 'Xi',
+ 'Omicron', 'Pi', 'Rho', 'Sigma', 'Tau', 'Upsilon',
+ 'Phi', 'Chi', 'Psi', 'Omega', 'alpha', 'beta',
+ 'gamma', 'delta', 'epsilon', 'zeta', 'eta', 'theta',
+ 'iota', 'kappa', 'lambda', 'mu', 'nu', 'xi',
+ 'omicron', 'pi', 'rho', 'sigmaf', 'sigma', 'tau',
+ 'upsilon', 'phi', 'chi', 'psi', 'omega', 'thetasym',
+ 'upsih', 'piv', 'bull', 'hellip', 'prime', 'Prime',
+ 'oline', 'frasl', 'weierp', 'image', 'real', 'trade',
+ 'alefsym', 'larr', 'uarr', 'rarr', 'darr', 'harr',
+ 'crarr', 'lArr', 'uArr', 'rArr', 'dArr', 'hArr',
+ 'forall', 'part', 'exist', 'empty', 'nabla', 'isin',
+ 'notin', 'ni', 'prod', 'sum', 'minus', 'lowast',
+ 'radic', 'prop', 'infin', 'ang', 'and', 'or',
+ 'cap', 'cup', 'int', 'sim', 'cong', 'asymp',
+ 'ne', 'equiv', 'le', 'ge', 'sub', 'sup',
+ 'nsub', 'sube', 'supe', 'oplus', 'otimes', 'perp',
+ 'sdot', 'lceil', 'rceil', 'lfloor', 'rfloor', 'lang',
+ 'rang', 'loz', 'spades', 'clubs', 'hearts', 'diams',
+ );
}
/**
- * wp_kses() - Filters content and keeps only allowable HTML elements.
+ * Filters content and keeps only allowable HTML elements.
*
- * This function makes sure that only the allowed HTML element names,
- * attribute names and attribute values plus only sane HTML entities
- * will occur in $string. You have to remove any slashes from PHP's
- * magic quotes before you call this function.
+ * This function makes sure that only the allowed HTML element names, attribute
+ * names and attribute values plus only sane HTML entities will occur in
+ * $string. You have to remove any slashes from PHP's magic quotes before you
+ * call this function.
*
- * The default allowed protocols are 'http', 'https', 'ftp', 'mailto',
- * 'news', 'irc', 'gopher', 'nntp', 'feed', and finally 'telnet. This
- * covers all common link protocols, except for 'javascript' which
- * should not be allowed for untrusted users.
+ * The default allowed protocols are 'http', 'https', 'ftp', 'mailto', 'news',
+ * 'irc', 'gopher', 'nntp', 'feed', 'telnet, 'mms', 'rtsp' and 'svn'. This
+ * covers all common link protocols, except for 'javascript' which should not
+ * be allowed for untrusted users.
*
* @since 1.0.0
*
@@ -342,7 +499,9 @@ if (!CUSTOM_TAGS) {
* @param array $allowed_protocols Optional. Allowed protocol in links.
* @return string Filtered content with only allowed HTML elements
*/
-function wp_kses($string, $allowed_html, $allowed_protocols = array ('http', 'https', 'ftp', 'ftps', 'mailto', 'news', 'irc', 'gopher', 'nntp', 'feed', 'telnet')) {
+function wp_kses($string, $allowed_html, $allowed_protocols = array ()) {
+ if ( empty( $allowed_protocols ) )
+ $allowed_protocols = wp_allowed_protocols();
$string = wp_kses_no_null($string);
$string = wp_kses_js_entities($string);
$string = wp_kses_normalize_entities($string);
@@ -352,11 +511,10 @@ function wp_kses($string, $allowed_html, $allowed_protocols = array ('http', 'ht
}
/**
- * wp_kses_hook() - You add any kses hooks here.
+ * You add any kses hooks here.
*
- * There is currently only one kses WordPress hook and it is
- * called here. All parameters are passed to the hooks and
- * expected to recieve a string.
+ * There is currently only one kses WordPress hook and it is called here. All
+ * parameters are passed to the hooks and expected to receive a string.
*
* @since 1.0.0
*
@@ -371,18 +529,18 @@ function wp_kses_hook($string, $allowed_html, $allowed_protocols) {
}
/**
- * wp_kses_version() - This function returns kses' version number.
+ * This function returns kses' version number.
*
* @since 1.0.0
*
- * @return string Version Number
+ * @return string KSES Version Number
*/
function wp_kses_version() {
return '0.2.2';
}
/**
- * wp_kses_split() - Searches for HTML tags, no matter how malformed
+ * Searches for HTML tags, no matter how malformed.
*
* It also matches stray ">" characters.
*
@@ -394,22 +552,36 @@ function wp_kses_version() {
* @return string Content with fixed HTML tags
*/
function wp_kses_split($string, $allowed_html, $allowed_protocols) {
- return preg_replace('%((|$))|(<[^>]*(>|$)|>))%e',
- "wp_kses_split2('\\1', \$allowed_html, ".'$allowed_protocols)', $string);
+ global $pass_allowed_html, $pass_allowed_protocols;
+ $pass_allowed_html = $allowed_html;
+ $pass_allowed_protocols = $allowed_protocols;
+ return preg_replace_callback( '%(|$))|(<[^>]*(>|$)|>)%', '_wp_kses_split_callback', $string );
+}
+
+/**
+ * Callback for wp_kses_split.
+ *
+ * @since 3.1.0
+ * @access private
+ */
+function _wp_kses_split_callback( $match ) {
+ global $pass_allowed_html, $pass_allowed_protocols;
+ return wp_kses_split2( $match[0], $pass_allowed_html, $pass_allowed_protocols );
}
/**
- * wp_kses_split2() - Callback for wp_kses_split for fixing malformed HTML tags
+ * Callback for wp_kses_split for fixing malformed HTML tags.
*
- * This function does a lot of work. It rejects some very malformed things
- * like <:::>. It returns an empty string, if the element isn't allowed (look
- * ma, no strip_tags()!). Otherwise it splits the tag into an element and an
- * attribute list.
+ * This function does a lot of work. It rejects some very malformed things like
+ * <:::>. It returns an empty string, if the element isn't allowed (look ma, no
+ * strip_tags()!). Otherwise it splits the tag into an element and an attribute
+ * list.
*
* After the tag is split into an element and an attribute list, it is run
- * through another filter which will remove illegal attributes and once
- * that is completed, will be returned.
+ * through another filter which will remove illegal attributes and once that is
+ * completed, will be returned.
*
+ * @access private
* @since 1.0.0
* @uses wp_kses_attr()
*
@@ -425,9 +597,9 @@ function wp_kses_split2($string, $allowed_html, $allowed_protocols) {
return '>';
# It matched a ">" character
- if (preg_match('%^)?$%', $string, $matches)) {
- $string = str_replace(array(''), '', $matches[1]);
- while ( $string != $newstring = wp_kses($string, $allowed_html, $allowed_protocols) )
+ if ( ''), '', $string );
+ while ( $string != ($newstring = wp_kses($string, $allowed_html, $allowed_protocols)) )
$string = $newstring;
if ( $string == '' )
return '';
@@ -447,25 +619,25 @@ function wp_kses_split2($string, $allowed_html, $allowed_protocols) {
$elem = $matches[2];
$attrlist = $matches[3];
- if (!@isset($allowed_html[strtolower($elem)]))
+ if ( ! isset($allowed_html[strtolower($elem)]) )
return '';
# They are using a not allowed HTML element
if ($slash != '')
- return "<$slash$elem>";
+ return "$elem>";
# No attributes are allowed for closing elements
- return wp_kses_attr("$slash$elem", $attrlist, $allowed_html, $allowed_protocols);
+ return wp_kses_attr( $elem, $attrlist, $allowed_html, $allowed_protocols );
}
/**
- * wp_kses_attr() - Removes all attributes, if none are allowed for this element
+ * Removes all attributes, if none are allowed for this element.
*
* If some are allowed it calls wp_kses_hair() to split them further, and then
* it builds up new HTML code from the data that kses_hair() returns. It also
- * removes "<" and ">" characters, if there are any left. One more thing it
- * does is to check if the tag has a closing XHTML slash, and if it does, it
- * puts one in the returned code as well.
+ * removes "<" and ">" characters, if there are any left. One more thing it does
+ * is to check if the tag has a closing XHTML slash, and if it does, it puts one
+ * in the returned code as well.
*
* @since 1.0.0
*
@@ -479,43 +651,53 @@ function wp_kses_attr($element, $attr, $allowed_html, $allowed_protocols) {
# Is there a closing XHTML slash at the end of the attributes?
$xhtml_slash = '';
- if (preg_match('%\s/\s*$%', $attr))
+ if (preg_match('%\s*/\s*$%', $attr))
$xhtml_slash = ' /';
# Are any attributes allowed at all for this element?
-
- if (@ count($allowed_html[strtolower($element)]) == 0)
+ if ( ! isset($allowed_html[strtolower($element)]) || count($allowed_html[strtolower($element)]) == 0 )
return "<$element$xhtml_slash>";
# Split it
-
$attrarr = wp_kses_hair($attr, $allowed_protocols);
# Go through $attrarr, and save the allowed attributes for this element
# in $attr2
-
$attr2 = '';
+ $allowed_attr = $allowed_html[strtolower($element)];
foreach ($attrarr as $arreach) {
- if (!@ isset ($allowed_html[strtolower($element)][strtolower($arreach['name'])]))
+ if ( ! isset( $allowed_attr[strtolower($arreach['name'])] ) )
continue; # the attribute is not allowed
- $current = $allowed_html[strtolower($element)][strtolower($arreach['name'])];
- if ($current == '')
+ $current = $allowed_attr[strtolower($arreach['name'])];
+ if ( $current == '' )
continue; # the attribute is not allowed
- if (!is_array($current))
+ if ( ! is_array($current) ) {
$attr2 .= ' '.$arreach['whole'];
# there are no checks
- else {
+ } else {
# there are some checks
$ok = true;
- foreach ($current as $currkey => $currval)
- if (!wp_kses_check_attr_val($arreach['value'], $arreach['vless'], $currkey, $currval)) {
+ foreach ($current as $currkey => $currval) {
+ if ( ! wp_kses_check_attr_val($arreach['value'], $arreach['vless'], $currkey, $currval) ) {
$ok = false;
break;
}
+ }
+
+ if ( strtolower($arreach['name']) == 'style' ) {
+ $orig_value = $arreach['value'];
+ $value = safecss_filter_attr($orig_value);
+
+ if ( empty($value) )
+ continue;
+
+ $arreach['value'] = $value;
+ $arreach['whole'] = str_replace($orig_value, $value, $arreach['whole']);
+ }
if ($ok)
$attr2 .= ' '.$arreach['whole']; # it passed them
@@ -523,14 +705,13 @@ function wp_kses_attr($element, $attr, $allowed_html, $allowed_protocols) {
} # foreach
# Remove any "<" or ">" characters
-
$attr2 = preg_replace('/[<>]/', '', $attr2);
return "<$element$attr2$xhtml_slash>";
}
/**
- * wp_kses_hair() - Builds an attribute list from string containing attributes.
+ * Builds an attribute list from string containing attributes.
*
* This function does a lot of work. It parses an attribute list into an array
* with attribute data, and tries to do the right thing even if it gets weird
@@ -550,6 +731,7 @@ function wp_kses_hair($attr, $allowed_protocols) {
$attrarr = array ();
$mode = 0;
$attrname = '';
+ $uris = array('xmlns', 'profile', 'href', 'src', 'cite', 'classid', 'codebase', 'data', 'usemap', 'longdesc', 'action');
# Loop through the whole attribute list
@@ -591,10 +773,12 @@ function wp_kses_hair($attr, $allowed_protocols) {
case 2 : # attribute value, a URL after href= for instance
- if (preg_match('/^"([^"]*)"(\s+|$)/', $attr, $match))
+ if (preg_match('%^"([^"]*)"(\s+|/?$)%', $attr, $match))
# "value"
{
- $thisval = wp_kses_bad_protocol($match[1], $allowed_protocols);
+ $thisval = $match[1];
+ if ( in_array(strtolower($attrname), $uris) )
+ $thisval = wp_kses_bad_protocol($thisval, $allowed_protocols);
if(FALSE === array_key_exists($attrname, $attrarr)) {
$attrarr[$attrname] = array ('name' => $attrname, 'value' => $thisval, 'whole' => "$attrname=\"$thisval\"", 'vless' => 'n');
@@ -605,10 +789,12 @@ function wp_kses_hair($attr, $allowed_protocols) {
break;
}
- if (preg_match("/^'([^']*)'(\s+|$)/", $attr, $match))
+ if (preg_match("%^'([^']*)'(\s+|/?$)%", $attr, $match))
# 'value'
{
- $thisval = wp_kses_bad_protocol($match[1], $allowed_protocols);
+ $thisval = $match[1];
+ if ( in_array(strtolower($attrname), $uris) )
+ $thisval = wp_kses_bad_protocol($thisval, $allowed_protocols);
if(FALSE === array_key_exists($attrname, $attrarr)) {
$attrarr[$attrname] = array ('name' => $attrname, 'value' => $thisval, 'whole' => "$attrname='$thisval'", 'vless' => 'n');
@@ -619,10 +805,12 @@ function wp_kses_hair($attr, $allowed_protocols) {
break;
}
- if (preg_match("%^([^\s\"']+)(\s+|$)%", $attr, $match))
+ if (preg_match("%^([^\s\"']+)(\s+|/?$)%", $attr, $match))
# value
{
- $thisval = wp_kses_bad_protocol($match[1], $allowed_protocols);
+ $thisval = $match[1];
+ if ( in_array(strtolower($attrname), $uris) )
+ $thisval = wp_kses_bad_protocol($thisval, $allowed_protocols);
if(FALSE === array_key_exists($attrname, $attrarr)) {
$attrarr[$attrname] = array ('name' => $attrname, 'value' => $thisval, 'whole' => "$attrname=\"$thisval\"", 'vless' => 'n');
@@ -652,18 +840,18 @@ function wp_kses_hair($attr, $allowed_protocols) {
}
/**
- * wp_kses_check_attr_val() - Performs different checks for attribute values.
+ * Performs different checks for attribute values.
*
* The currently implemented checks are "maxlen", "minlen", "maxval", "minval"
- * and "valueless" with even more checks to come soon.
+ * and "valueless".
*
* @since 1.0.0
*
* @param string $value Attribute value
- * @param string $vless Whether the value is valueless or not. Use 'y' or 'n'
+ * @param string $vless Whether the value is valueless. Use 'y' or 'n'
* @param string $checkname What $checkvalue is checking for.
* @param mixed $checkvalue What constraint the value should pass
- * @return bool Whether check passes (true) or not (false)
+ * @return bool Whether check passes
*/
function wp_kses_check_attr_val($value, $vless, $checkname, $checkvalue) {
$ok = true;
@@ -700,7 +888,7 @@ function wp_kses_check_attr_val($value, $vless, $checkname, $checkvalue) {
break;
case 'minval' :
- # The minval check checks that the attribute value is a positive integer,
+ # The minval check makes sure that the attribute value is a positive integer,
# and that it is not smaller than the given value.
if (!preg_match('/^\s{0,6}[0-9]{1,6}\s{0,6}$/', $value))
@@ -710,7 +898,7 @@ function wp_kses_check_attr_val($value, $vless, $checkname, $checkvalue) {
break;
case 'valueless' :
- # The valueless check checks if the attribute has a value
+ # The valueless check makes sure if the attribute has a value
# (like ) or not (