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<?php
/**
* WordPress API for creating bbcode-like tags or what WordPress calls
* "shortcodes". The tag and attribute parsing or regular expression code is
* based on the Textpattern tag parser.
*
* A few examples are below:
*
* [shortcode /]
* [shortcode foo="bar" baz="bing" /]
* [shortcode foo="bar"]content[/shortcode]
*
* Shortcode tags support attributes and enclosed content, but does not entirely
* support inline shortcodes in other shortcodes. You will have to call the
* shortcode parser in your function to account for that.
*
* {@internal
* Please be aware that the above note was made during the beta of WordPress 2.6
* and in the future may not be accurate. Please update the note when it is no
* longer the case.}}
*
* To apply shortcode tags to content:
*
* $out = do_shortcode( $content );
*
* @link https://codex.wordpress.org/Shortcode_API
*
* @package WordPress
* @subpackage Shortcodes
* @since 2.5.0
*/
/**
* Container for storing shortcode tags and their hook to call for the shortcode
*
* @since 2.5.0
*
* @name $shortcode_tags
* @var array
* @global array $shortcode_tags
*/
$shortcode_tags = array();
/**
* Adds a new shortcode.
*
* Care should be taken through prefixing or other means to ensure that the
* shortcode tag being added is unique and will not conflict with other,
* already-added shortcode tags. In the event of a duplicated tag, the tag
* loaded last will take precedence.
*
* @since 2.5.0
*
* @global array $shortcode_tags
*
* @param string $tag Shortcode tag to be searched in post content.
* @param callable $callback The callback function to run when the shortcode is found.
* Every shortcode callback is passed three parameters by default,
* including an array of attributes (`$atts`), the shortcode content
* or null if not set (`$content`), and finally the shortcode tag
* itself (`$shortcode_tag`), in that order.
*/
function add_shortcode( $tag, $callback ) {
global $shortcode_tags;
if ( '' == trim( $tag ) ) {
$message = __( 'Invalid shortcode name: Empty name given.' );
_doing_it_wrong( __FUNCTION__, $message, '4.4.0' );
return;
}
if ( 0 !== preg_match( '@[<>&/\[\]\x00-\x20=]@', $tag ) ) {
/* translators: 1: shortcode name, 2: space separated list of reserved characters */
$message = sprintf( __( 'Invalid shortcode name: %1$s. Do not use spaces or reserved characters: %2$s' ), $tag, '& / < > [ ] =' );
_doing_it_wrong( __FUNCTION__, $message, '4.4.0' );
return;
}
$shortcode_tags[ $tag ] = $callback;
}
/**
* Removes hook for shortcode.
*
* @since 2.5.0
*
* @global array $shortcode_tags
*
* @param string $tag Shortcode tag to remove hook for.
*/
function remove_shortcode( $tag ) {
global $shortcode_tags;
unset( $shortcode_tags[ $tag ] );
}
/**
* Clear all shortcodes.
*
* This function is simple, it clears all of the shortcode tags by replacing the
* shortcodes global by a empty array. This is actually a very efficient method
* for removing all shortcodes.
*
* @since 2.5.0
*
* @global array $shortcode_tags
*/
function remove_all_shortcodes() {
global $shortcode_tags;
$shortcode_tags = array();
}
/**
* Whether a registered shortcode exists named $tag
*
* @since 3.6.0
*
* @global array $shortcode_tags List of shortcode tags and their callback hooks.
*
* @param string $tag Shortcode tag to check.
* @return bool Whether the given shortcode exists.
*/
function shortcode_exists( $tag ) {
global $shortcode_tags;
return array_key_exists( $tag, $shortcode_tags );
}
/**
* Whether the passed content contains the specified shortcode
*
* @since 3.6.0
*
* @global array $shortcode_tags
*
* @param string $content Content to search for shortcodes.
* @param string $tag Shortcode tag to check.
* @return bool Whether the passed content contains the given shortcode.
*/
function has_shortcode( $content, $tag ) {
if ( false === strpos( $content, '[' ) ) {
return false;
}
if ( shortcode_exists( $tag ) ) {
preg_match_all( '/' . get_shortcode_regex() . '/', $content, $matches, PREG_SET_ORDER );
if ( empty( $matches ) ) {
return false;
}
foreach ( $matches as $shortcode ) {
if ( $tag === $shortcode[2] ) {
return true;
} elseif ( ! empty( $shortcode[5] ) && has_shortcode( $shortcode[5], $tag ) ) {
return true;
}
}
}
return false;
}
/**
* Search content for shortcodes and filter shortcodes through their hooks.
*
* If there are no shortcode tags defined, then the content will be returned
* without any filtering. This might cause issues when plugins are disabled but
* the shortcode will still show up in the post or content.
*
* @since 2.5.0
*
* @global array $shortcode_tags List of shortcode tags and their callback hooks.
*
* @param string $content Content to search for shortcodes.
* @param bool $ignore_html When true, shortcodes inside HTML elements will be skipped.
* @return string Content with shortcodes filtered out.
*/
function do_shortcode( $content, $ignore_html = false ) {
global $shortcode_tags;
if ( false === strpos( $content, '[' ) ) {
return $content;
}
if ( empty( $shortcode_tags ) || ! is_array( $shortcode_tags ) ) {
return $content;
}
// Find all registered tag names in $content.
preg_match_all( '@\[([^<>&/\[\]\x00-\x20=]++)@', $content, $matches );
$tagnames = array_intersect( array_keys( $shortcode_tags ), $matches[1] );
if ( empty( $tagnames ) ) {
return $content;
}
$content = do_shortcodes_in_html_tags( $content, $ignore_html, $tagnames );
$pattern = get_shortcode_regex( $tagnames );
$content = preg_replace_callback( "/$pattern/", 'do_shortcode_tag', $content );
// Always restore square braces so we don't break things like <!--[if IE ]>
$content = unescape_invalid_shortcodes( $content );
return $content;
}
/**
* Retrieve the shortcode regular expression for searching.
*
* The regular expression combines the shortcode tags in the regular expression
* in a regex class.
*
* The regular expression contains 6 different sub matches to help with parsing.
*
* 1 - An extra [ to allow for escaping shortcodes with double [[]]
* 2 - The shortcode name
* 3 - The shortcode argument list
* 4 - The self closing /
* 5 - The content of a shortcode when it wraps some content.
* 6 - An extra ] to allow for escaping shortcodes with double [[]]
*
* @since 2.5.0
* @since 4.4.0 Added the `$tagnames` parameter.
*
* @global array $shortcode_tags
*
* @param array $tagnames Optional. List of shortcodes to find. Defaults to all registered shortcodes.
* @return string The shortcode search regular expression
*/
function get_shortcode_regex( $tagnames = null ) {
global $shortcode_tags;
if ( empty( $tagnames ) ) {
$tagnames = array_keys( $shortcode_tags );
}
$tagregexp = join( '|', array_map( 'preg_quote', $tagnames ) );
// WARNING! Do not change this regex without changing do_shortcode_tag() and strip_shortcode_tag()
// Also, see shortcode_unautop() and shortcode.js.
// phpcs:disable Squiz.Strings.ConcatenationSpacing.PaddingFound -- don't remove regex indentation
return
'\\[' // Opening bracket
. '(\\[?)' // 1: Optional second opening bracket for escaping shortcodes: [[tag]]
. "($tagregexp)" // 2: Shortcode name
. '(?![\\w-])' // Not followed by word character or hyphen
. '(' // 3: Unroll the loop: Inside the opening shortcode tag
. '[^\\]\\/]*' // Not a closing bracket or forward slash
. '(?:'
. '\\/(?!\\])' // A forward slash not followed by a closing bracket
. '[^\\]\\/]*' // Not a closing bracket or forward slash
. ')*?'
. ')'
. '(?:'
. '(\\/)' // 4: Self closing tag ...
. '\\]' // ... and closing bracket
. '|'
. '\\]' // Closing bracket
. '(?:'
. '(' // 5: Unroll the loop: Optionally, anything between the opening and closing shortcode tags
. '[^\\[]*+' // Not an opening bracket
. '(?:'
. '\\[(?!\\/\\2\\])' // An opening bracket not followed by the closing shortcode tag
. '[^\\[]*+' // Not an opening bracket
. ')*+'
. ')'
. '\\[\\/\\2\\]' // Closing shortcode tag
. ')?'
. ')'
. '(\\]?)'; // 6: Optional second closing brocket for escaping shortcodes: [[tag]]
// phpcs:enable
}
/**
* Regular Expression callable for do_shortcode() for calling shortcode hook.
*
* @see get_shortcode_regex for details of the match array contents.
*
* @since 2.5.0
* @access private
*
* @global array $shortcode_tags
*
* @param array $m Regular expression match array
* @return string|false False on failure.
*/
function do_shortcode_tag( $m ) {
global $shortcode_tags;
// allow [[foo]] syntax for escaping a tag
if ( $m[1] == '[' && $m[6] == ']' ) {
return substr( $m[0], 1, -1 );
}
$tag = $m[2];
$attr = shortcode_parse_atts( $m[3] );
if ( ! is_callable( $shortcode_tags[ $tag ] ) ) {
/* translators: %s: shortcode tag */
$message = sprintf( __( 'Attempting to parse a shortcode without a valid callback: %s' ), $tag );
_doing_it_wrong( __FUNCTION__, $message, '4.3.0' );
return $m[0];
}
/**
* Filters whether to call a shortcode callback.
*
* Passing a truthy value to the filter will effectively short-circuit the
* shortcode generation process, returning that value instead.
*
* @since 4.7.0
*
* @param bool|string $return Short-circuit return value. Either false or the value to replace the shortcode with.
* @param string $tag Shortcode name.
* @param array|string $attr Shortcode attributes array or empty string.
* @param array $m Regular expression match array.
*/
$return = apply_filters( 'pre_do_shortcode_tag', false, $tag, $attr, $m );
if ( false !== $return ) {
return $return;
}
$content = isset( $m[5] ) ? $m[5] : null;
$output = $m[1] . call_user_func( $shortcode_tags[ $tag ], $attr, $content, $tag ) . $m[6];
/**
* Filters the output created by a shortcode callback.
*
* @since 4.7.0
*
* @param string $output Shortcode output.
* @param string $tag Shortcode name.
* @param array|string $attr Shortcode attributes array or empty string.
* @param array $m Regular expression match array.
*/
return apply_filters( 'do_shortcode_tag', $output, $tag, $attr, $m );
}
/**
* Search only inside HTML elements for shortcodes and process them.
*
* Any [ or ] characters remaining inside elements will be HTML encoded
* to prevent interference with shortcodes that are outside the elements.
* Assumes $content processed by KSES already. Users with unfiltered_html
* capability may get unexpected output if angle braces are nested in tags.
*
* @since 4.2.3
*
* @param string $content Content to search for shortcodes
* @param bool $ignore_html When true, all square braces inside elements will be encoded.
* @param array $tagnames List of shortcodes to find.
* @return string Content with shortcodes filtered out.
*/
function do_shortcodes_in_html_tags( $content, $ignore_html, $tagnames ) {
// Normalize entities in unfiltered HTML before adding placeholders.
$trans = array(
'&#91;' => '&#091;',
'&#93;' => '&#093;',
);
$content = strtr( $content, $trans );
$trans = array(
'[' => '&#91;',
']' => '&#93;',
);
$pattern = get_shortcode_regex( $tagnames );
$textarr = wp_html_split( $content );
foreach ( $textarr as &$element ) {
if ( '' == $element || '<' !== $element[0] ) {
continue;
}
$noopen = false === strpos( $element, '[' );
$noclose = false === strpos( $element, ']' );
if ( $noopen || $noclose ) {
// This element does not contain shortcodes.
if ( $noopen xor $noclose ) {
// Need to encode stray [ or ] chars.
$element = strtr( $element, $trans );
}
continue;
}
if ( $ignore_html || '<!--' === substr( $element, 0, 4 ) || '<![CDATA[' === substr( $element, 0, 9 ) ) {
// Encode all [ and ] chars.
$element = strtr( $element, $trans );
continue;
}
$attributes = wp_kses_attr_parse( $element );
if ( false === $attributes ) {
// Some plugins are doing things like [name] <[email]>.
if ( 1 === preg_match( '%^<\s*\[\[?[^\[\]]+\]%', $element ) ) {
$element = preg_replace_callback( "/$pattern/", 'do_shortcode_tag', $element );
}
// Looks like we found some crazy unfiltered HTML. Skipping it for sanity.
$element = strtr( $element, $trans );
continue;
}
// Get element name
$front = array_shift( $attributes );
$back = array_pop( $attributes );
$matches = array();
preg_match( '%[a-zA-Z0-9]+%', $front, $matches );
$elname = $matches[0];
// Look for shortcodes in each attribute separately.
foreach ( $attributes as &$attr ) {
$open = strpos( $attr, '[' );
$close = strpos( $attr, ']' );
if ( false === $open || false === $close ) {
continue; // Go to next attribute. Square braces will be escaped at end of loop.
}
$double = strpos( $attr, '"' );
$single = strpos( $attr, "'" );
if ( ( false === $single || $open < $single ) && ( false === $double || $open < $double ) ) {
// $attr like '[shortcode]' or 'name = [shortcode]' implies unfiltered_html.
// In this specific situation we assume KSES did not run because the input
// was written by an administrator, so we should avoid changing the output
// and we do not need to run KSES here.
$attr = preg_replace_callback( "/$pattern/", 'do_shortcode_tag', $attr );
} else {
// $attr like 'name = "[shortcode]"' or "name = '[shortcode]'"
// We do not know if $content was unfiltered. Assume KSES ran before shortcodes.
$count = 0;
$new_attr = preg_replace_callback( "/$pattern/", 'do_shortcode_tag', $attr, -1, $count );
if ( $count > 0 ) {
// Sanitize the shortcode output using KSES.
$new_attr = wp_kses_one_attr( $new_attr, $elname );
if ( '' !== trim( $new_attr ) ) {
// The shortcode is safe to use now.
$attr = $new_attr;
}
}
}
}
$element = $front . implode( '', $attributes ) . $back;
// Now encode any remaining [ or ] chars.
$element = strtr( $element, $trans );
}
$content = implode( '', $textarr );
return $content;
}
/**
* Remove placeholders added by do_shortcodes_in_html_tags().
*
* @since 4.2.3
*
* @param string $content Content to search for placeholders.
* @return string Content with placeholders removed.
*/
function unescape_invalid_shortcodes( $content ) {
// Clean up entire string, avoids re-parsing HTML.
$trans = array(
'&#91;' => '[',
'&#93;' => ']',
);
$content = strtr( $content, $trans );
return $content;
}
/**
* Retrieve the shortcode attributes regex.
*
* @since 4.4.0
*
* @return string The shortcode attribute regular expression
*/
function get_shortcode_atts_regex() {
return '/([\w-]+)\s*=\s*"([^"]*)"(?:\s|$)|([\w-]+)\s*=\s*\'([^\']*)\'(?:\s|$)|([\w-]+)\s*=\s*([^\s\'"]+)(?:\s|$)|"([^"]*)"(?:\s|$)|\'([^\']*)\'(?:\s|$)|(\S+)(?:\s|$)/';
}
/**
* Retrieve all attributes from the shortcodes tag.
*
* The attributes list has the attribute name as the key and the value of the
* attribute as the value in the key/value pair. This allows for easier
* retrieval of the attributes, since all attributes have to be known.
*
* @since 2.5.0
*
* @param string $text
* @return array|string List of attribute values.
* Returns empty array if trim( $text ) == '""'.
* Returns empty string if trim( $text ) == ''.
* All other matches are checked for not empty().
*/
function shortcode_parse_atts( $text ) {
$atts = array();
$pattern = get_shortcode_atts_regex();
$text = preg_replace( "/[\x{00a0}\x{200b}]+/u", ' ', $text );
if ( preg_match_all( $pattern, $text, $match, PREG_SET_ORDER ) ) {
foreach ( $match as $m ) {
if ( ! empty( $m[1] ) ) {
$atts[ strtolower( $m[1] ) ] = stripcslashes( $m[2] );
} elseif ( ! empty( $m[3] ) ) {
$atts[ strtolower( $m[3] ) ] = stripcslashes( $m[4] );
} elseif ( ! empty( $m[5] ) ) {
$atts[ strtolower( $m[5] ) ] = stripcslashes( $m[6] );
} elseif ( isset( $m[7] ) && strlen( $m[7] ) ) {
$atts[] = stripcslashes( $m[7] );
} elseif ( isset( $m[8] ) && strlen( $m[8] ) ) {
$atts[] = stripcslashes( $m[8] );
} elseif ( isset( $m[9] ) ) {
$atts[] = stripcslashes( $m[9] );
}
}
// Reject any unclosed HTML elements
foreach ( $atts as &$value ) {
if ( false !== strpos( $value, '<' ) ) {
if ( 1 !== preg_match( '/^[^<]*+(?:<[^>]*+>[^<]*+)*+$/', $value ) ) {
$value = '';
}
}
}
} else {
$atts = ltrim( $text );
}
return $atts;
}
/**
* Combine user attributes with known attributes and fill in defaults when needed.
*
* The pairs should be considered to be all of the attributes which are
* supported by the caller and given as a list. The returned attributes will
* only contain the attributes in the $pairs list.
*
* If the $atts list has unsupported attributes, then they will be ignored and
* removed from the final returned list.
*
* @since 2.5.0
*
* @param array $pairs Entire list of supported attributes and their defaults.
* @param array $atts User defined attributes in shortcode tag.
* @param string $shortcode Optional. The name of the shortcode, provided for context to enable filtering
* @return array Combined and filtered attribute list.
*/
function shortcode_atts( $pairs, $atts, $shortcode = '' ) {
$atts = (array) $atts;
$out = array();
foreach ( $pairs as $name => $default ) {
if ( array_key_exists( $name, $atts ) ) {
$out[ $name ] = $atts[ $name ];
} else {
$out[ $name ] = $default;
}
}
/**
* Filters a shortcode's default attributes.
*
* If the third parameter of the shortcode_atts() function is present then this filter is available.
* The third parameter, $shortcode, is the name of the shortcode.
*
* @since 3.6.0
* @since 4.4.0 Added the `$shortcode` parameter.
*
* @param array $out The output array of shortcode attributes.
* @param array $pairs The supported attributes and their defaults.
* @param array $atts The user defined shortcode attributes.
* @param string $shortcode The shortcode name.
*/
if ( $shortcode ) {
$out = apply_filters( "shortcode_atts_{$shortcode}", $out, $pairs, $atts, $shortcode );
}
return $out;
}
/**
* Remove all shortcode tags from the given content.
*
* @since 2.5.0
*
* @global array $shortcode_tags
*
* @param string $content Content to remove shortcode tags.
* @return string Content without shortcode tags.
*/
function strip_shortcodes( $content ) {
global $shortcode_tags;
if ( false === strpos( $content, '[' ) ) {
return $content;
}
if ( empty( $shortcode_tags ) || ! is_array( $shortcode_tags ) ) {
return $content;
}
// Find all registered tag names in $content.
preg_match_all( '@\[([^<>&/\[\]\x00-\x20=]++)@', $content, $matches );
$tags_to_remove = array_keys( $shortcode_tags );
/**
* Filters the list of shortcode tags to remove from the content.
*
* @since 4.7.0
*
* @param array $tags_to_remove Array of shortcode tags to remove.
* @param string $content Content shortcodes are being removed from.
*/
$tags_to_remove = apply_filters( 'strip_shortcodes_tagnames', $tags_to_remove, $content );
$tagnames = array_intersect( $tags_to_remove, $matches[1] );
if ( empty( $tagnames ) ) {
return $content;
}
$content = do_shortcodes_in_html_tags( $content, true, $tagnames );
$pattern = get_shortcode_regex( $tagnames );
$content = preg_replace_callback( "/$pattern/", 'strip_shortcode_tag', $content );
// Always restore square braces so we don't break things like <!--[if IE ]>
$content = unescape_invalid_shortcodes( $content );
return $content;
}
/**
* Strips a shortcode tag based on RegEx matches against post content.
*
* @since 3.3.0
*
* @param array $m RegEx matches against post content.
* @return string|false The content stripped of the tag, otherwise false.
*/
function strip_shortcode_tag( $m ) {
// allow [[foo]] syntax for escaping a tag
if ( $m[1] == '[' && $m[6] == ']' ) {
return substr( $m[0], 1, -1 );
}
return $m[1] . $m[6];
}