source: trunk/src/wp-includes/bookmark-template.php

<?php
/**
 * Bookmark Template Functions for usage in Themes.
 *
 * @package WordPress
 * @subpackage Template
 */

/**
 * The formatted output of a list of bookmarks.
 *
 * The $bookmarks array must contain bookmark objects and will be iterated over
 * to retrieve the bookmark to be used in the output.
 *
 * The output is formatted as HTML with no way to change that format. However,
 * what is between, before, and after can be changed. The link itself will be
 * HTML.
 *
 * This function is used internally by wp_list_bookmarks() and should not be
 * used by themes.
 *
 * @since 2.1.0
 * @access private
 *
 * @param array        $bookmarks List of bookmarks to traverse.
 * @param string|array $args {
 *     Optional. Bookmarks arguments.
 *
 *     @type int|bool $show_updated     Whether to show the time the bookmark was last updated.
 *                                      Accepts 1|true or 0|false. Default 0|false.
 *     @type int|bool $show_description Whether to show the bookmark description. Accepts 1|true,
 *                                      Accepts 1|true or 0|false. Default 0|false.
 *     @type int|bool $show_images      Whether to show the link image if available. Accepts 1|true
 *                                      or 0|false. Default 1|true.
 *     @type int|bool $show_name        Whether to show link name if available. Accepts 1|true or
 *                                      0|false. Default 0|false.
 *     @type string   $before           The HTML or text to prepend to each bookmark. Default `<li>`.
 *     @type string   $after            The HTML or text to append to each bookmark. Default `</li>`.
 *     @type string   $link_before      The HTML or text to prepend to each bookmark inside the anchor
 *                                      tags. Default empty.
 *     @type string   $link_after       The HTML or text to append to each bookmark inside the anchor
 *                                      tags. Default empty.
 *     @type string   $between          The string for use in between the link, description, and image.
 *                                      Default "\n".
 *     @type int|bool $show_rating      Whether to show the link rating. Accepts 1|true or 0|false.
 *                                      Default 0|false.
 *
 * }
 * @return string Formatted output in HTML
 */
function _walk_bookmarks( $bookmarks, $args = '' ) {
        $defaults = array(
                'show_updated'     => 0,
                'show_description' => 0,
                'show_images'      => 1,
                'show_name'        => 0,
                'before'           => '<li>',
                'after'            => '</li>',
                'between'          => "\n",
                'show_rating'      => 0,
                'link_before'      => '',
                'link_after'       => '',
        );

        $parsed_args = wp_parse_args( $args, $defaults );

        $output = ''; // Blank string to start with.

        foreach ( (array) $bookmarks as $bookmark ) {
                if ( ! isset( $bookmark->recently_updated ) ) {
                        $bookmark->recently_updated = false;
                }
                $output .= $parsed_args['before'];
                if ( $parsed_args['show_updated'] && $bookmark->recently_updated ) {
                        $output .= '<em>';
                }
                $the_link = '#';
                if ( ! empty( $bookmark->link_url ) ) {
                        $the_link = esc_url( $bookmark->link_url );
                }
                $desc  = esc_attr( sanitize_bookmark_field( 'link_description', $bookmark->link_description, $bookmark->link_id, 'display' ) );
                $name  = esc_attr( sanitize_bookmark_field( 'link_name', $bookmark->link_name, $bookmark->link_id, 'display' ) );
                $title = $desc;

                if ( $parsed_args['show_updated'] ) {
                        if ( ! str_starts_with( $bookmark->link_updated_f, '00' ) ) {
                                $title .= ' (';
                                $title .= sprintf(
                                        /* translators: %s: Date and time of last update. */
                                        __( 'Last updated: %s' ),
                                        gmdate(
                                                get_option( 'links_updated_date_format' ),
                                                $bookmark->link_updated_f + ( get_option( 'gmt_offset' ) * HOUR_IN_SECONDS )
                                        )
                                );
                                $title .= ')';
                        }
                }
                $alt = ' alt="' . $name . ( $parsed_args['show_description'] ? ' ' . $title : '' ) . '"';

                if ( '' !== $title ) {
                        $title = ' title="' . $title . '"';
                }
                $rel = $bookmark->link_rel;

                $target = $bookmark->link_target;
                if ( '' !== $target ) {
                        if ( is_string( $rel ) && '' !== $rel ) {
                                if ( ! str_contains( $rel, 'noopener' ) ) {
                                        $rel = trim( $rel ) . ' noopener';
                                }
                        } else {
                                $rel = 'noopener';
                        }

                        $target = ' target="' . $target . '"';
                }

                if ( '' !== $rel ) {
                        $rel = ' rel="' . esc_attr( $rel ) . '"';
                }

                $output .= '<a href="' . $the_link . '"' . $rel . $title . $target . '>';

                $output .= $parsed_args['link_before'];

                if ( '' !== $bookmark->link_image && $parsed_args['show_images'] ) {
                        if ( str_starts_with( $bookmark->link_image, 'http' ) ) {
                                $output .= '<img src="' . $bookmark->link_image . '"' . $alt . $title . ' />';
                        } else { // If it's a relative path.
                                $output .= '<img src="' . get_option( 'siteurl' ) . $bookmark->link_image . '"' . $alt . $title . ' />';
                        }
                        if ( $parsed_args['show_name'] ) {
                                $output .= " $name";
                        }
                } else {
                        $output .= $name;
                }

                $output .= $parsed_args['link_after'];

                $output .= '</a>';

                if ( $parsed_args['show_updated'] && $bookmark->recently_updated ) {
                        $output .= '</em>';
                }

                if ( $parsed_args['show_description'] && '' !== $desc ) {
                        $output .= $parsed_args['between'] . $desc;
                }

                if ( $parsed_args['show_rating'] ) {
                        $output .= $parsed_args['between'] . sanitize_bookmark_field(
                                'link_rating',
                                $bookmark->link_rating,
                                $bookmark->link_id,
                                'display'
                        );
                }
                $output .= $parsed_args['after'] . "\n";
        } // End while.

        return $output;
}

/**
 * Retrieves or echoes all of the bookmarks.
 *
 * List of default arguments are as follows:
 *
 * These options define how the Category name will appear before the category
 * links are displayed, if 'categorize' is 1. If 'categorize' is 0, then it will
 * display for only the 'title_li' string and only if 'title_li' is not empty.
 *
 * @since 2.1.0
 *
 * @see _walk_bookmarks()
 *
 * @param string|array $args {
 *     Optional. String or array of arguments to list bookmarks.
 *
 *     @type string       $orderby          How to order the links by. Accepts post fields. Default 'name'.
 *     @type string       $order            Whether to order bookmarks in ascending or descending order.
 *                                          Accepts 'ASC' (ascending) or 'DESC' (descending). Default 'ASC'.
 *     @type int          $limit            Amount of bookmarks to display. Accepts 1+ or -1 for all.
 *                                          Default -1.
 *     @type string       $category         Comma-separated list of category IDs to include links from.
 *                                          Default empty.
 *     @type string       $category_name    Category to retrieve links for by name. Default empty.
 *     @type int|bool     $hide_invisible   Whether to show or hide links marked as 'invisible'. Accepts
 *                                          1|true or 0|false. Default 1|true.
 *     @type int|bool     $show_updated     Whether to display the time the bookmark was last updated.
 *                                          Accepts 1|true or 0|false. Default 0|false.
 *     @type int|bool     $echo             Whether to echo or return the formatted bookmarks. Accepts
 *                                          1|true (echo) or 0|false (return). Default 1|true.
 *     @type int|bool     $categorize       Whether to show links listed by category or in a single column.
 *                                          Accepts 1|true (by category) or 0|false (one column). Default 1|true.
 *     @type int|bool     $show_description Whether to show the bookmark descriptions. Accepts 1|true or 0|false.
 *                                          Default 0|false.
 *     @type string       $title_li         What to show before the links appear. Default 'Bookmarks'.
 *     @type string       $title_before     The HTML or text to prepend to the $title_li string. Default '<h2>'.
 *     @type string       $title_after      The HTML or text to append to the $title_li string. Default '</h2>'.
 *     @type string|array $class            The CSS class or an array of classes to use for the $title_li.
 *                                          Default 'linkcat'.
 *     @type string       $category_before  The HTML or text to prepend to $title_before if $categorize is true.
 *                                          String must contain '%id' and '%class' to inherit the category ID and
 *                                          the $class argument used for formatting in themes.
 *                                          Default '<li id="%id" class="%class">'.
 *     @type string       $category_after   The HTML or text to append to $title_after if $categorize is true.
 *                                          Default '</li>'.
 *     @type string       $category_orderby How to order the bookmark category based on term scheme if $categorize
 *                                          is true. Default 'name'.
 *     @type string       $category_order   Whether to order categories in ascending or descending order if
 *                                          $categorize is true. Accepts 'ASC' (ascending) or 'DESC' (descending).
 *                                          Default 'ASC'.
 * }
 * @return void|string Void if 'echo' argument is true, HTML list of bookmarks if 'echo' is false.
 */
function wp_list_bookmarks( $args = '' ) {
        $defaults = array(
                'orderby'          => 'name',
                'order'            => 'ASC',
                'limit'            => -1,
                'category'         => '',
                'exclude_category' => '',
                'category_name'    => '',
                'hide_invisible'   => 1,
                'show_updated'     => 0,
                'echo'             => 1,
                'categorize'       => 1,
                'title_li'         => __( 'Bookmarks' ),
                'title_before'     => '<h2>',
                'title_after'      => '</h2>',
                'category_orderby' => 'name',
                'category_order'   => 'ASC',
                'class'            => 'linkcat',
                'category_before'  => '<li id="%id" class="%class">',
                'category_after'   => '</li>',
        );

        $parsed_args = wp_parse_args( $args, $defaults );

        $output = '';

        if ( ! is_array( $parsed_args['class'] ) ) {
                $parsed_args['class'] = explode( ' ', $parsed_args['class'] );
        }
        $parsed_args['class'] = array_map( 'sanitize_html_class', $parsed_args['class'] );
        $parsed_args['class'] = trim( implode( ' ', $parsed_args['class'] ) );

        if ( $parsed_args['categorize'] ) {
                $cats = get_terms(
                        array(
                                'taxonomy'     => 'link_category',
                                'name__like'   => $parsed_args['category_name'],
                                'include'      => $parsed_args['category'],
                                'exclude'      => $parsed_args['exclude_category'],
                                'orderby'      => $parsed_args['category_orderby'],
                                'order'        => $parsed_args['category_order'],
                                'hierarchical' => 0,
                        )
                );
                if ( empty( $cats ) ) {
                        $parsed_args['categorize'] = false;
                }
        }

        if ( $parsed_args['categorize'] ) {
                // Split the bookmarks into ul's for each category.
                foreach ( (array) $cats as $cat ) {
                        $params    = array_merge( $parsed_args, array( 'category' => $cat->term_id ) );
                        $bookmarks = get_bookmarks( $params );
                        if ( empty( $bookmarks ) ) {
                                continue;
                        }
                        $output .= str_replace(
                                array( '%id', '%class' ),
                                array( "linkcat-$cat->term_id", $parsed_args['class'] ),
                                $parsed_args['category_before']
                        );
                        /**
                         * Filters the category name.
                         *
                         * @since 2.2.0
                         *
                         * @param string $cat_name The category name.
                         */
                        $catname = apply_filters( 'link_category', $cat->name );

                        $output .= $parsed_args['title_before'];
                        $output .= $catname;
                        $output .= $parsed_args['title_after'];
                        $output .= "\n\t<ul class='xoxo blogroll'>\n";
                        $output .= _walk_bookmarks( $bookmarks, $parsed_args );
                        $output .= "\n\t</ul>\n";
                        $output .= $parsed_args['category_after'] . "\n";
                }
        } else {
                // Output one single list using title_li for the title.
                $bookmarks = get_bookmarks( $parsed_args );

                if ( ! empty( $bookmarks ) ) {
                        if ( ! empty( $parsed_args['title_li'] ) ) {
                                $output .= str_replace(
                                        array( '%id', '%class' ),
                                        array( 'linkcat-' . $parsed_args['category'], $parsed_args['class'] ),
                                        $parsed_args['category_before']
                                );
                                $output .= $parsed_args['title_before'];
                                $output .= $parsed_args['title_li'];
                                $output .= $parsed_args['title_after'];
                                $output .= "\n\t<ul class='xoxo blogroll'>\n";
                                $output .= _walk_bookmarks( $bookmarks, $parsed_args );
                                $output .= "\n\t</ul>\n";
                                $output .= $parsed_args['category_after'] . "\n";
                        } else {
                                $output .= _walk_bookmarks( $bookmarks, $parsed_args );
                        }
                }
        }

        /**
         * Filters the bookmarks list before it is echoed or returned.
         *
         * @since 2.5.0
         *
         * @param string $html The HTML list of bookmarks.
         */
        $html = apply_filters( 'wp_list_bookmarks', $output );

        if ( $parsed_args['echo'] ) {
                echo $html;
        } else {
                return $html;
        }
}