WordPress/wp-admin/includes/bookmark.php

<?php

function add_link() {
	return edit_link();
}

function edit_link( $link_id = '' ) {
	if (!current_user_can( 'manage_links' ))
		wp_die( __( 'Cheatin&#8217; uh?' ));

	$_POST['link_url'] = wp_specialchars( $_POST['link_url'] );
	$_POST['link_url'] = clean_url($_POST['link_url']);
	$_POST['link_name'] = wp_specialchars( $_POST['link_name'] );
	$_POST['link_image'] = wp_specialchars( $_POST['link_image'] );
	$_POST['link_rss'] = clean_url($_POST['link_rss']);
	if ( 'N' != $_POST['link_visible'] )
		$_POST['link_visible'] = 'Y';

	if ( !empty( $link_id ) ) {
		$_POST['link_id'] = $link_id;
		return wp_update_link( $_POST);
	} else {
		return wp_insert_link( $_POST);
	}
}

function get_default_link_to_edit() {
	if ( isset( $_GET['linkurl'] ) )
		$link->link_url = clean_url( $_GET['linkurl']);
	else
		$link->link_url = '';

	if ( isset( $_GET['name'] ) )
		$link->link_name = attribute_escape( $_GET['name']);
	else
		$link->link_name = '';

	$link->link_visible = 'Y';

	return $link;
}

function wp_delete_link($link_id) {
	global $wpdb;

	do_action('delete_link', $link_id);

	wp_delete_object_term_relationships($link_id, 'link_category');

	$wpdb->query( $wpdb->prepare("DELETE FROM $wpdb->links WHERE link_id = %d", $link_id) );

	do_action('deleted_link', $link_id);

	return true;
}

function wp_get_link_cats($link_id = 0) {

	$cats = wp_get_object_terms($link_id, 'link_category', 'fields=ids');

	return array_unique($cats);
}

function get_link_to_edit( $link_id ) {
	return get_bookmark( $link_id, OBJECT, 'edit' );
}

function wp_insert_link($linkdata) {
	global $wpdb, $current_user;

	$defaults = array('link_id' => 0, 'link_name' => '', 'link_url' => '', 'link_rating' => 0 );

	$linkdata = wp_parse_args($linkdata, $defaults);
	$linkdata = sanitize_bookmark($linkdata, 'db');

	extract(stripslashes_deep($linkdata), EXTR_SKIP);

	$update = false;

	if ( !empty($link_id) )
		$update = true;

	if ( trim( $link_name ) == '' )
		return 0;

	if ( trim( $link_url ) == '' )
		return 0;

	if ( empty($link_rating) )
		$link_rating = 0;

	if ( empty($link_image) )
		$link_image = '';

	if ( empty($link_target) )
		$link_target = '';

	if ( empty($link_visible) )
		$link_visible = 'Y';

	if ( empty($link_owner) )
		$link_owner = $current_user->id;

	if ( empty($link_notes) )
		$link_notes = '';

	if ( empty($link_description) )
		$link_description = '';

	if ( empty($link_rss) )
		$link_rss = '';

	if ( empty($link_rel) )
		$link_rel = '';

	// Make sure we set a valid category
	if (0 == count($link_category) || !is_array($link_category)) {
		$link_category = array(get_option('default_link_category'));
	}

	if ( $update ) {
		$wpdb->query( $wpdb->prepare("UPDATE $wpdb->links SET link_url = %s,
			link_name = %s, link_image = %s, link_target = %s, 
			link_visible = %s, link_description = %s, link_rating = %s, 
			link_rel = %s, link_notes = %s, link_rss = %s
			WHERE link_id = %s", $link_url, $link_name, $link_image, $link_target, $link_visible, $link_description, $link_rating, $link_rel, $link_notes, $link_rss, $link_id) );
	} else {
		$wpdb->query( $wpdb->prepare("INSERT INTO $wpdb->links (link_url, link_name, link_image, link_target, link_description, link_visible, link_owner, link_rating, link_rel, link_notes, link_rss) VALUES(%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)", 
		$link_url,$link_name, $link_image, $link_target, $link_description, $link_visible, $link_owner, $link_rating, $link_rel, $link_notes, $link_rss) );
		$link_id = (int) $wpdb->insert_id;
	}

	wp_set_link_cats($link_id, $link_category);

	if ( $update )
		do_action('edit_link', $link_id);
	else
		do_action('add_link', $link_id);

	return $link_id;
}

function wp_set_link_cats($link_id = 0, $link_categories = array()) {
	// If $link_categories isn't already an array, make it one:
	if (!is_array($link_categories) || 0 == count($link_categories))
		$link_categories = array(get_option('default_link_category'));

	$link_categories = array_map('intval', $link_categories);
	$link_categories = array_unique($link_categories);

	wp_set_object_terms($link_id, $link_categories, 'link_category');
}	// wp_set_link_cats()

function wp_update_link($linkdata) {
	$link_id = (int) $linkdata['link_id'];

	$link = get_link($link_id, ARRAY_A);

	// Escape data pulled from DB.
	$link = add_magic_quotes($link);

	// Passed link category list overwrites existing category list if not empty.
	if ( isset($linkdata['link_category']) && is_array($linkdata['link_category'])
			 && 0 != count($linkdata['link_category']) )
		$link_cats = $linkdata['link_category'];
	else
		$link_cats = $link['link_category'];

	// Merge old and new fields with new fields overwriting old ones.
	$linkdata = array_merge($link, $linkdata);
	$linkdata['link_category'] = $link_cats;

	return wp_insert_link($linkdata);
}

?>