HTML Examples/WP.iso/wordpress/wp-includes/shortcodes.php

PHP Script | 2017-08-20 | 20.0 KB | 631 lines

<?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.
    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]]
}

/**
 * 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( '[' => '[', ']' => ']' );
    $content = strtr( $content, $trans );
    $trans = array( '[' => '[', ']' => ']' );

    $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( '[' => '[', ']' => ']' );
        $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  $tag_array 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];
}