WordPress/wp-admin/includes/ajax-actions.php

<?php
/**
 * WordPress Core Ajax Handlers.
 *
 * @package WordPress
 * @subpackage Administration
 */

/*
 * No-privilege Ajax handlers.
 */
function wp_ajax_nopriv_heartbeat() {
	$response = array();

	// screen_id is the same as $current_screen->id and the JS global 'pagenow'
	if ( ! empty($_POST['screenid']) )
		$screen_id = sanitize_key($_POST['screenid']);
	else
		$screen_id = 'site';

	if ( ! empty($_POST['data']) ) {
		$data = wp_unslash( (array) $_POST['data'] );
		$response = apply_filters( 'heartbeat_nopriv_received', $response, $data, $screen_id );
	}

	$response = apply_filters( 'heartbeat_nopriv_send', $response, $screen_id );

	// Allow the transport to be replaced with long-polling easily
	do_action( 'heartbeat_nopriv_tick', $response, $screen_id );

	// send the current time according to the server
	$response['servertime'] = time();

	wp_send_json($response);
}

/*
 * GET-based Ajax handlers.
 */
function wp_ajax_fetch_list() {
	global $wp_list_table;

	$list_class = $_GET['list_args']['class'];
	check_ajax_referer( "fetch-list-$list_class", '_ajax_fetch_list_nonce' );

	$wp_list_table = _get_list_table( $list_class, array( 'screen' => $_GET['list_args']['screen']['id'] ) );
	if ( ! $wp_list_table )
		wp_die( 0 );

	if ( ! $wp_list_table->ajax_user_can() )
		wp_die( -1 );

	$wp_list_table->ajax_response();

	wp_die( 0 );
}
function wp_ajax_ajax_tag_search() {
	global $wpdb;

	if ( isset( $_GET['tax'] ) ) {
		$taxonomy = sanitize_key( $_GET['tax'] );
		$tax = get_taxonomy( $taxonomy );
		if ( ! $tax )
			wp_die( 0 );
		if ( ! current_user_can( $tax->cap->assign_terms ) )
			wp_die( -1 );
	} else {
		wp_die( 0 );
	}

	$s = wp_unslash( $_GET['q'] );

	$comma = _x( ',', 'tag delimiter' );
	if ( ',' !== $comma )
		$s = str_replace( $comma, ',', $s );
	if ( false !== strpos( $s, ',' ) ) {
		$s = explode( ',', $s );
		$s = $s[count( $s ) - 1];
	}
	$s = trim( $s );
	if ( strlen( $s ) < 2 )
		wp_die(); // require 2 chars for matching

	$results = $wpdb->get_col( $wpdb->prepare( "SELECT t.name FROM $wpdb->term_taxonomy AS tt INNER JOIN $wpdb->terms AS t ON tt.term_id = t.term_id WHERE tt.taxonomy = %s AND t.name LIKE (%s)", $taxonomy, '%' . like_escape( $s ) . '%' ) );

	echo join( $results, "\n" );
	wp_die();
}

function wp_ajax_wp_compression_test() {
	if ( !current_user_can( 'manage_options' ) )
		wp_die( -1 );

	if ( ini_get('zlib.output_compression') || 'ob_gzhandler' == ini_get('output_handler') ) {
		update_site_option('can_compress_scripts', 0);
		wp_die( 0 );
	}

	if ( isset($_GET['test']) ) {
		header( 'Expires: Wed, 11 Jan 1984 05:00:00 GMT' );
		header( 'Last-Modified: ' . gmdate( 'D, d M Y H:i:s' ) . ' GMT' );
		header( 'Cache-Control: no-cache, must-revalidate, max-age=0' );
		header( 'Pragma: no-cache' );
		header('Content-Type: application/x-javascript; charset=UTF-8');
		$force_gzip = ( defined('ENFORCE_GZIP') && ENFORCE_GZIP );
		$test_str = '"wpCompressionTest Lorem ipsum dolor sit amet consectetuer mollis sapien urna ut a. Eu nonummy condimentum fringilla tempor pretium platea vel nibh netus Maecenas. Hac molestie amet justo quis pellentesque est ultrices interdum nibh Morbi. Cras mattis pretium Phasellus ante ipsum ipsum ut sociis Suspendisse Lorem. Ante et non molestie. Porta urna Vestibulum egestas id congue nibh eu risus gravida sit. Ac augue auctor Ut et non a elit massa id sodales. Elit eu Nulla at nibh adipiscing mattis lacus mauris at tempus. Netus nibh quis suscipit nec feugiat eget sed lorem et urna. Pellentesque lacus at ut massa consectetuer ligula ut auctor semper Pellentesque. Ut metus massa nibh quam Curabitur molestie nec mauris congue. Volutpat molestie elit justo facilisis neque ac risus Ut nascetur tristique. Vitae sit lorem tellus et quis Phasellus lacus tincidunt nunc Fusce. Pharetra wisi Suspendisse mus sagittis libero lacinia Integer consequat ac Phasellus. Et urna ac cursus tortor aliquam Aliquam amet tellus volutpat Vestibulum. Justo interdum condimentum In augue congue tellus sollicitudin Quisque quis nibh."';

		 if ( 1 == $_GET['test'] ) {
		 	echo $test_str;
		 	wp_die();
		 } elseif ( 2 == $_GET['test'] ) {
			if ( !isset($_SERVER['HTTP_ACCEPT_ENCODING']) )
				wp_die( -1 );
			if ( false !== stripos( $_SERVER['HTTP_ACCEPT_ENCODING'], 'deflate') && function_exists('gzdeflate') && ! $force_gzip ) {
				header('Content-Encoding: deflate');
				$out = gzdeflate( $test_str, 1 );
			} elseif ( false !== stripos( $_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') && function_exists('gzencode') ) {
				header('Content-Encoding: gzip');
				$out = gzencode( $test_str, 1 );
			} else {
				wp_die( -1 );
			}
			echo $out;
			wp_die();
		} elseif ( 'no' == $_GET['test'] ) {
			update_site_option('can_compress_scripts', 0);
		} elseif ( 'yes' == $_GET['test'] ) {
			update_site_option('can_compress_scripts', 1);
		}
	}

	wp_die( 0 );
}

function wp_ajax_imgedit_preview() {
	$post_id = intval($_GET['postid']);
	if ( empty($post_id) || !current_user_can('edit_post', $post_id) )
		wp_die( -1 );

	check_ajax_referer( "image_editor-$post_id" );

	include_once( ABSPATH . 'wp-admin/includes/image-edit.php' );
	if ( ! stream_preview_image($post_id) )
		wp_die( -1 );

	wp_die();
}

function wp_ajax_oembed_cache() {
	global $wp_embed;

	$return = ( $wp_embed->cache_oembed( $_GET['post'] ) ) ? '1' : '0';
	wp_die( $return );
}

function wp_ajax_autocomplete_user() {
	if ( ! is_multisite() || ! current_user_can( 'promote_users' ) || wp_is_large_network( 'users' ) )
		wp_die( -1 );

	if ( ! is_super_admin() && ! apply_filters( 'autocomplete_users_for_site_admins', false ) )
		wp_die( -1 );

	$return = array();

	// Check the type of request
	if ( isset( $_REQUEST['autocomplete_type'] ) )
		$type = $_REQUEST['autocomplete_type'];
	else
		$type = 'add';

	// Exclude current users of this blog
	if ( isset( $_REQUEST['site_id'] ) )
		$id = absint( $_REQUEST['site_id'] );
	else
		$id = get_current_blog_id();

	$include_blog_users = ( $type == 'search' ? get_users( array( 'blog_id' => $id, 'fields' => 'ID' ) ) : array() );
	$exclude_blog_users = ( $type == 'add' ? get_users( array( 'blog_id' => $id, 'fields' => 'ID' ) ) : array() );

	$users = get_users( array(
		'blog_id' => false,
		'search'  => '*' . $_REQUEST['term'] . '*',
		'include' => $include_blog_users,
		'exclude' => $exclude_blog_users,
		'search_columns' => array( 'user_login', 'user_nicename', 'user_email' ),
	) );

	foreach ( $users as $user ) {
		$return[] = array(
			/* translators: 1: user_login, 2: user_email */
			'label' => sprintf( __( '%1$s (%2$s)' ), $user->user_login, $user->user_email ),
			'value' => $user->user_login,
		);
	}

	wp_die( json_encode( $return ) );
}

function wp_ajax_dashboard_widgets() {
	require_once ABSPATH . 'wp-admin/includes/dashboard.php';

	switch ( $_GET['widget'] ) {
		case 'dashboard_incoming_links' :
			wp_dashboard_incoming_links();
			break;
		case 'dashboard_primary' :
			wp_dashboard_primary();
			break;
		case 'dashboard_secondary' :
			wp_dashboard_secondary();
			break;
		case 'dashboard_plugins' :
			wp_dashboard_plugins();
			break;
	}
	wp_die();
}

function wp_ajax_logged_in() {
	wp_die( 1 );
}

/*
 * Ajax helper.
 */

/**
 * Sends back current comment total and new page links if they need to be updated.
 *
 * Contrary to normal success AJAX response ("1"), die with time() on success.
 *
 * @since 2.7
 *
 * @param int $comment_id
 * @return die
 */
function _wp_ajax_delete_comment_response( $comment_id, $delta = -1 ) {
	$total = (int) @$_POST['_total'];
	$per_page = (int) @$_POST['_per_page'];
	$page = (int) @$_POST['_page'];
	$url = esc_url_raw( @$_POST['_url'] );
	// JS didn't send us everything we need to know. Just die with success message
	if ( !$total || !$per_page || !$page || !$url )
		wp_die( time() );

	$total += $delta;
	if ( $total < 0 )
		$total = 0;

	// Only do the expensive stuff on a page-break, and about 1 other time per page
	if ( 0 == $total % $per_page || 1 == mt_rand( 1, $per_page ) ) {
		$post_id = 0;
		$status = 'total_comments'; // What type of comment count are we looking for?
		$parsed = parse_url( $url );
		if ( isset( $parsed['query'] ) ) {
			parse_str( $parsed['query'], $query_vars );
			if ( !empty( $query_vars['comment_status'] ) )
				$status = $query_vars['comment_status'];
			if ( !empty( $query_vars['p'] ) )
				$post_id = (int) $query_vars['p'];
		}

		$comment_count = wp_count_comments($post_id);

		if ( isset( $comment_count->$status ) ) // We're looking for a known type of comment count
			$total = $comment_count->$status;
			// else use the decremented value from above
	}

	$time = time(); // The time since the last comment count

	$x = new WP_Ajax_Response( array(
		'what' => 'comment',
		'id' => $comment_id, // here for completeness - not used
		'supplemental' => array(
			'total_items_i18n' => sprintf( _n( '1 item', '%s items', $total ), number_format_i18n( $total ) ),
			'total_pages' => ceil( $total / $per_page ),
			'total_pages_i18n' => number_format_i18n( ceil( $total / $per_page ) ),
			'total' => $total,
			'time' => $time
		)
	) );
	$x->send();
}

/*
 * POST-based Ajax handlers.
 */

function _wp_ajax_add_hierarchical_term() {
	$action = $_POST['action'];
	$taxonomy = get_taxonomy(substr($action, 4));
	check_ajax_referer( $action, '_ajax_nonce-add-' . $taxonomy->name );
	if ( !current_user_can( $taxonomy->cap->edit_terms ) )
		wp_die( -1 );
	$names = explode(',', $_POST['new'.$taxonomy->name]);
	$parent = isset($_POST['new'.$taxonomy->name.'_parent']) ? (int) $_POST['new'.$taxonomy->name.'_parent'] : 0;
	if ( 0 > $parent )
		$parent = 0;
	if ( $taxonomy->name == 'category' )
		$post_category = isset($_POST['post_category']) ? (array) $_POST['post_category'] : array();
	else
		$post_category = ( isset($_POST['tax_input']) && isset($_POST['tax_input'][$taxonomy->name]) ) ? (array) $_POST['tax_input'][$taxonomy->name] : array();
	$checked_categories = array_map( 'absint', (array) $post_category );
	$popular_ids = wp_popular_terms_checklist($taxonomy->name, 0, 10, false);

	foreach ( $names as $cat_name ) {
		$cat_name = trim($cat_name);
		$category_nicename = sanitize_title($cat_name);
		if ( '' === $category_nicename )
			continue;
		if ( !$cat_id = term_exists( $cat_name, $taxonomy->name, $parent ) )
			$cat_id = wp_insert_term( $cat_name, $taxonomy->name, array( 'parent' => $parent ) );
		if ( is_wp_error( $cat_id ) )
			continue;
		else if ( is_array( $cat_id ) )
			$cat_id = $cat_id['term_id'];
		$checked_categories[] = $cat_id;
		if ( $parent ) // Do these all at once in a second
			continue;
		ob_start();
			wp_terms_checklist( 0, array( 'taxonomy' => $taxonomy->name, 'descendants_and_self' => $cat_id, 'selected_cats' => $checked_categories, 'popular_cats' => $popular_ids ));
		$data = ob_get_contents();
		ob_end_clean();
		$add = array(
			'what' => $taxonomy->name,
			'id' => $cat_id,
			'data' => str_replace( array("\n", "\t"), '', $data),
			'position' => -1
		);
	}

	if ( $parent ) { // Foncy - replace the parent and all its children
		$parent = get_term( $parent, $taxonomy->name );
		$term_id = $parent->term_id;

		while ( $parent->parent ) { // get the top parent
			$parent = get_term( $parent->parent, $taxonomy->name );
			if ( is_wp_error( $parent ) )
				break;
			$term_id = $parent->term_id;
		}

		ob_start();
			wp_terms_checklist( 0, array('taxonomy' => $taxonomy->name, 'descendants_and_self' => $term_id, 'selected_cats' => $checked_categories, 'popular_cats' => $popular_ids));
		$data = ob_get_contents();
		ob_end_clean();
		$add = array(
			'what' => $taxonomy->name,
			'id' => $term_id,
			'data' => str_replace( array("\n", "\t"), '', $data),
			'position' => -1
		);
	}

	ob_start();
		wp_dropdown_categories( array(
			'taxonomy' => $taxonomy->name, 'hide_empty' => 0, 'name' => 'new'.$taxonomy->name.'_parent', 'orderby' => 'name',
			'hierarchical' => 1, 'show_option_none' => '&mdash; '.$taxonomy->labels->parent_item.' &mdash;'
		) );
	$sup = ob_get_contents();
	ob_end_clean();
	$add['supplemental'] = array( 'newcat_parent' => $sup );

	$x = new WP_Ajax_Response( $add );
	$x->send();
}

function wp_ajax_delete_comment() {
	$id = isset( $_POST['id'] ) ? (int) $_POST['id'] : 0;

	if ( !$comment = get_comment( $id ) )
		wp_die( time() );
	if ( ! current_user_can( 'edit_comment', $comment->comment_ID ) )
		wp_die( -1 );

	check_ajax_referer( "delete-comment_$id" );
	$status = wp_get_comment_status( $comment->comment_ID );

	$delta = -1;
	if ( isset($_POST['trash']) && 1 == $_POST['trash'] ) {
		if ( 'trash' == $status )
			wp_die( time() );
		$r = wp_trash_comment( $comment->comment_ID );
	} elseif ( isset($_POST['untrash']) && 1 == $_POST['untrash'] ) {
		if ( 'trash' != $status )
			wp_die( time() );
		$r = wp_untrash_comment( $comment->comment_ID );
		if ( ! isset( $_POST['comment_status'] ) || $_POST['comment_status'] != 'trash' ) // undo trash, not in trash
			$delta = 1;
	} elseif ( isset($_POST['spam']) && 1 == $_POST['spam'] ) {
		if ( 'spam' == $status )
			wp_die( time() );
		$r = wp_spam_comment( $comment->comment_ID );
	} elseif ( isset($_POST['unspam']) && 1 == $_POST['unspam'] ) {
		if ( 'spam' != $status )
			wp_die( time() );
		$r = wp_unspam_comment( $comment->comment_ID );
		if ( ! isset( $_POST['comment_status'] ) || $_POST['comment_status'] != 'spam' ) // undo spam, not in spam
			$delta = 1;
	} elseif ( isset($_POST['delete']) && 1 == $_POST['delete'] ) {
		$r = wp_delete_comment( $comment->comment_ID );
	} else {
		wp_die( -1 );
	}

	if ( $r ) // Decide if we need to send back '1' or a more complicated response including page links and comment counts
		_wp_ajax_delete_comment_response( $comment->comment_ID, $delta );
	wp_die( 0 );
}

function wp_ajax_delete_tag() {
	$tag_id = (int) $_POST['tag_ID'];
	check_ajax_referer( "delete-tag_$tag_id" );

	$taxonomy = !empty($_POST['taxonomy']) ? $_POST['taxonomy'] : 'post_tag';
	$tax = get_taxonomy($taxonomy);

	if ( !current_user_can( $tax->cap->delete_terms ) )
		wp_die( -1 );

	$tag = get_term( $tag_id, $taxonomy );
	if ( !$tag || is_wp_error( $tag ) )
		wp_die( 1 );

	if ( wp_delete_term($tag_id, $taxonomy))
		wp_die( 1 );
	else
		wp_die( 0 );
}

function wp_ajax_delete_link() {
	$id = isset( $_POST['id'] ) ? (int) $_POST['id'] : 0;

	check_ajax_referer( "delete-bookmark_$id" );
	if ( !current_user_can( 'manage_links' ) )
		wp_die( -1 );

	$link = get_bookmark( $id );
	if ( !$link || is_wp_error( $link ) )
		wp_die( 1 );

	if ( wp_delete_link( $id ) )
		wp_die( 1 );
	else
		wp_die( 0 );
}

function wp_ajax_delete_meta() {
	$id = isset( $_POST['id'] ) ? (int) $_POST['id'] : 0;

	check_ajax_referer( "delete-meta_$id" );
	if ( !$meta = get_metadata_by_mid( 'post', $id ) )
		wp_die( 1 );

	if ( is_protected_meta( $meta->meta_key, 'post' ) || ! current_user_can( 'delete_post_meta',  $meta->post_id, $meta->meta_key ) )
		wp_die( -1 );
	if ( delete_meta( $meta->meta_id ) )
		wp_die( 1 );
	wp_die( 0 );
}

function wp_ajax_delete_post( $action ) {
	if ( empty( $action ) )
		$action = 'delete-post';
	$id = isset( $_POST['id'] ) ? (int) $_POST['id'] : 0;

	check_ajax_referer( "{$action}_$id" );
	if ( !current_user_can( 'delete_post', $id ) )
		wp_die( -1 );

	if ( !get_post( $id ) )
		wp_die( 1 );

	if ( wp_delete_post( $id ) )
		wp_die( 1 );
	else
		wp_die( 0 );
}

function wp_ajax_trash_post( $action ) {
	if ( empty( $action ) )
		$action = 'trash-post';
	$id = isset( $_POST['id'] ) ? (int) $_POST['id'] : 0;

	check_ajax_referer( "{$action}_$id" );
	if ( !current_user_can( 'delete_post', $id ) )
		wp_die( -1 );

	if ( !get_post( $id ) )
		wp_die( 1 );

	if ( 'trash-post' == $action )
		$done = wp_trash_post( $id );
	else
		$done = wp_untrash_post( $id );

	if ( $done )
		wp_die( 1 );

	wp_die( 0 );
}

function wp_ajax_untrash_post( $action ) {
	if ( empty( $action ) )
		$action = 'untrash-post';
	wp_ajax_trash_post( $action );
}

function wp_ajax_delete_page( $action ) {
	if ( empty( $action ) )
		$action = 'delete-page';
	$id = isset( $_POST['id'] ) ? (int) $_POST['id'] : 0;

	check_ajax_referer( "{$action}_$id" );
	if ( !current_user_can( 'delete_page', $id ) )
		wp_die( -1 );

	if ( ! get_post( $id ) )
		wp_die( 1 );

	if ( wp_delete_post( $id ) )
		wp_die( 1 );
	else
		wp_die( 0 );
}

function wp_ajax_dim_comment() {
	$id = isset( $_POST['id'] ) ? (int) $_POST['id'] : 0;

	if ( !$comment = get_comment( $id ) ) {
		$x = new WP_Ajax_Response( array(
			'what' => 'comment',
			'id' => new WP_Error('invalid_comment', sprintf(__('Comment %d does not exist'), $id))
		) );
		$x->send();
	}

	if ( ! current_user_can( 'edit_comment', $comment->comment_ID ) && ! current_user_can( 'moderate_comments' ) )
		wp_die( -1 );

	$current = wp_get_comment_status( $comment->comment_ID );
	if ( $_POST['new'] == $current )
		wp_die( time() );

	check_ajax_referer( "approve-comment_$id" );
	if ( in_array( $current, array( 'unapproved', 'spam' ) ) )
		$result = wp_set_comment_status( $comment->comment_ID, 'approve', true );
	else
		$result = wp_set_comment_status( $comment->comment_ID, 'hold', true );

	if ( is_wp_error($result) ) {
		$x = new WP_Ajax_Response( array(
			'what' => 'comment',
			'id' => $result
		) );
		$x->send();
	}

	// Decide if we need to send back '1' or a more complicated response including page links and comment counts
	_wp_ajax_delete_comment_response( $comment->comment_ID );
	wp_die( 0 );
}

function wp_ajax_add_link_category( $action ) {
	if ( empty( $action ) )
		$action = 'add-link-category';
	check_ajax_referer( $action );
	if ( !current_user_can( 'manage_categories' ) )
		wp_die( -1 );
	$names = explode(',', wp_unslash( $_POST['newcat'] ) );
	$x = new WP_Ajax_Response();
	foreach ( $names as $cat_name ) {
		$cat_name = trim($cat_name);
		$slug = sanitize_title($cat_name);
		if ( '' === $slug )
			continue;
		if ( !$cat_id = term_exists( $cat_name, 'link_category' ) )
			$cat_id = wp_insert_term( $cat_name, 'link_category' );
		if ( is_wp_error( $cat_id ) )
			continue;
		else if ( is_array( $cat_id ) )
			$cat_id = $cat_id['term_id'];
		$cat_name = esc_html( $cat_name );
		$x->add( array(
			'what' => 'link-category',
			'id' => $cat_id,
			'data' => "<li id='link-category-$cat_id'><label for='in-link-category-$cat_id' class='selectit'><input value='" . esc_attr($cat_id) . "' type='checkbox' checked='checked' name='link_category[]' id='in-link-category-$cat_id'/> $cat_name</label></li>",
			'position' => -1
		) );
	}
	$x->send();
}

function wp_ajax_add_tag() {
	global $wp_list_table;

	check_ajax_referer( 'add-tag', '_wpnonce_add-tag' );
	$post_type = !empty($_POST['post_type']) ? $_POST['post_type'] : 'post';
	$taxonomy = !empty($_POST['taxonomy']) ? $_POST['taxonomy'] : 'post_tag';
	$tax = get_taxonomy($taxonomy);

	if ( !current_user_can( $tax->cap->edit_terms ) )
		wp_die( -1 );

	$x = new WP_Ajax_Response();

	$tag = wp_insert_term($_POST['tag-name'], $taxonomy, $_POST );

	if ( !$tag || is_wp_error($tag) || (!$tag = get_term( $tag['term_id'], $taxonomy )) ) {
		$message = __('An error has occurred. Please reload the page and try again.');
		if ( is_wp_error($tag) && $tag->get_error_message() )
			$message = $tag->get_error_message();

		$x->add( array(
			'what' => 'taxonomy',
			'data' => new WP_Error('error', $message )
		) );
		$x->send();
	}

	$wp_list_table = _get_list_table( 'WP_Terms_List_Table', array( 'screen' => $_POST['screen'] ) );

	$level = 0;
	if ( is_taxonomy_hierarchical($taxonomy) ) {
		$level = count( get_ancestors( $tag->term_id, $taxonomy ) );
		ob_start();
		$wp_list_table->single_row( $tag, $level );
		$noparents = ob_get_clean();
	}

	ob_start();
	$wp_list_table->single_row( $tag );
	$parents = ob_get_clean();

	$x->add( array(
		'what' => 'taxonomy',
		'supplemental' => compact('parents', 'noparents')
		) );
	$x->add( array(
		'what' => 'term',
		'position' => $level,
		'supplemental' => (array) $tag
		) );
	$x->send();
}

function wp_ajax_get_tagcloud() {
	if ( isset( $_POST['tax'] ) ) {
		$taxonomy = sanitize_key( $_POST['tax'] );
		$tax = get_taxonomy( $taxonomy );
		if ( ! $tax )
			wp_die( 0 );
		if ( ! current_user_can( $tax->cap->assign_terms ) )
			wp_die( -1 );
	} else {
		wp_die( 0 );
	}

	$tags = get_terms( $taxonomy, array( 'number' => 45, 'orderby' => 'count', 'order' => 'DESC' ) );

	if ( empty( $tags ) )
		wp_die( $tax->labels->not_found );

	if ( is_wp_error( $tags ) )
		wp_die( $tags->get_error_message() );

	foreach ( $tags as $key => $tag ) {
		$tags[ $key ]->link = '#';
		$tags[ $key ]->id = $tag->term_id;
	}

	// We need raw tag names here, so don't filter the output
	$return = wp_generate_tag_cloud( $tags, array('filter' => 0) );

	if ( empty($return) )
		wp_die( 0 );

	echo $return;

	wp_die();
}

function wp_ajax_get_comments( $action ) {
	global $wp_list_table, $post_id;
	if ( empty( $action ) )
		$action = 'get-comments';

	check_ajax_referer( $action );

	$wp_list_table = _get_list_table( 'WP_Post_Comments_List_Table', array( 'screen' => 'edit-comments' ) );

	if ( !current_user_can( 'edit_post', $post_id ) )
		wp_die( -1 );

	$wp_list_table->prepare_items();

	if ( !$wp_list_table->has_items() )
		wp_die( 1 );

	$x = new WP_Ajax_Response();
	ob_start();
	foreach ( $wp_list_table->items as $comment ) {
		if ( ! current_user_can( 'edit_comment', $comment->comment_ID ) )
			continue;
		get_comment( $comment );
		$wp_list_table->single_row( $comment );
	}
	$comment_list_item = ob_get_contents();
	ob_end_clean();

	$x->add( array(
		'what' => 'comments',
		'data' => $comment_list_item
	) );
	$x->send();
}

function wp_ajax_replyto_comment( $action ) {
	global $wp_list_table, $wpdb;
	if ( empty( $action ) )
		$action = 'replyto-comment';

	check_ajax_referer( $action, '_ajax_nonce-replyto-comment' );

	$comment_post_ID = (int) $_POST['comment_post_ID'];
	if ( !current_user_can( 'edit_post', $comment_post_ID ) )
		wp_die( -1 );

	$status = $wpdb->get_var( $wpdb->prepare("SELECT post_status FROM $wpdb->posts WHERE ID = %d", $comment_post_ID) );

	if ( empty($status) )
		wp_die( 1 );
	elseif ( in_array($status, array('draft', 'pending', 'trash') ) )
		wp_die( __('ERROR: you are replying to a comment on a draft post.') );

	$user = wp_get_current_user();
	if ( $user->exists() ) {
		$user_ID = $user->ID;
		$comment_author       = $wpdb->escape($user->display_name);
		$comment_author_email = $wpdb->escape($user->user_email);
		$comment_author_url   = $wpdb->escape($user->user_url);
		$comment_content      = trim($_POST['content']);
		if ( current_user_can( 'unfiltered_html' ) ) {
			if ( wp_create_nonce( 'unfiltered-html-comment' ) != $_POST['_wp_unfiltered_html_comment'] ) {
				kses_remove_filters(); // start with a clean slate
				kses_init_filters(); // set up the filters
			}
		}
	} else {
		wp_die( __( 'Sorry, you must be logged in to reply to a comment.' ) );
	}

	if ( '' == $comment_content )
		wp_die( __( 'ERROR: please type a comment.' ) );

	$comment_parent = absint($_POST['comment_ID']);
	$comment_auto_approved = false;
	$commentdata = compact('comment_post_ID', 'comment_author', 'comment_author_email', 'comment_author_url', 'comment_content', 'comment_type', 'comment_parent', 'user_ID');

	// automatically approve parent comment
	if ( !empty($_POST['approve_parent']) ) {
		$parent = get_comment( $comment_parent );

		if ( $parent && $parent->comment_approved === '0' && $parent->comment_post_ID == $comment_post_ID ) {
			if ( wp_set_comment_status( $parent->comment_ID, 'approve' ) )
				$comment_auto_approved = true;
		}
	}

	$comment_id = wp_new_comment( $commentdata );
	$comment = get_comment($comment_id);
	if ( ! $comment ) wp_die( 1 );

	$position = ( isset($_POST['position']) && (int) $_POST['position'] ) ? (int) $_POST['position'] : '-1';

	ob_start();
		if ( 'dashboard' == $_REQUEST['mode'] ) {
			require_once( ABSPATH . 'wp-admin/includes/dashboard.php' );
			_wp_dashboard_recent_comments_row( $comment );
		} else {
			if ( 'single' == $_REQUEST['mode'] ) {
				$wp_list_table = _get_list_table('WP_Post_Comments_List_Table', array( 'screen' => 'edit-comments' ) );
			} else {
				$wp_list_table = _get_list_table('WP_Comments_List_Table', array( 'screen' => 'edit-comments' ) );
			}
			$wp_list_table->single_row( $comment );
		}
		$comment_list_item = ob_get_contents();
	ob_end_clean();

	$response =  array(
		'what' => 'comment',
		'id' => $comment->comment_ID,
		'data' => $comment_list_item,
		'position' => $position
	);

	if ( $comment_auto_approved )
		$response['supplemental'] = array( 'parent_approved' => $parent->comment_ID );

	$x = new WP_Ajax_Response();
	$x->add( $response );
	$x->send();
}

function wp_ajax_edit_comment() {
	global $wp_list_table;

	check_ajax_referer( 'replyto-comment', '_ajax_nonce-replyto-comment' );

	$comment_id = (int) $_POST['comment_ID'];
	if ( ! current_user_can( 'edit_comment', $comment_id ) )
		wp_die( -1 );

	if ( '' == $_POST['content'] )
		wp_die( __( 'ERROR: please type a comment.' ) );

	$_POST['comment_status'] = $_POST['status'];
	edit_comment();

	$position = ( isset($_POST['position']) && (int) $_POST['position']) ? (int) $_POST['position'] : '-1';
	$comments_status = isset($_POST['comments_listing']) ? $_POST['comments_listing'] : '';

	$checkbox = ( isset($_POST['checkbox']) && true == $_POST['checkbox'] ) ? 1 : 0;
	$wp_list_table = _get_list_table( $checkbox ? 'WP_Comments_List_Table' : 'WP_Post_Comments_List_Table', array( 'screen' => 'edit-comments' ) );

	$comment = get_comment( $comment_id );

	ob_start();
		$wp_list_table->single_row( $comment );
		$comment_list_item = ob_get_contents();
	ob_end_clean();

	$x = new WP_Ajax_Response();

	$x->add( array(
		'what' => 'edit_comment',
		'id' => $comment->comment_ID,
		'data' => $comment_list_item,
		'position' => $position
	));

	$x->send();
}

function wp_ajax_add_menu_item() {
	check_ajax_referer( 'add-menu_item', 'menu-settings-column-nonce' );

	if ( ! current_user_can( 'edit_theme_options' ) )
		wp_die( -1 );

	require_once ABSPATH . 'wp-admin/includes/nav-menu.php';

	// For performance reasons, we omit some object properties from the checklist.
	// The following is a hacky way to restore them when adding non-custom items.

	$menu_items_data = array();
	foreach ( (array) $_POST['menu-item'] as $menu_item_data ) {
		if (
			! empty( $menu_item_data['menu-item-type'] ) &&
			'custom' != $menu_item_data['menu-item-type'] &&
			! empty( $menu_item_data['menu-item-object-id'] )
		) {
			switch( $menu_item_data['menu-item-type'] ) {
				case 'post_type' :
					$_object = get_post( $menu_item_data['menu-item-object-id'] );
				break;

				case 'taxonomy' :
					$_object = get_term( $menu_item_data['menu-item-object-id'], $menu_item_data['menu-item-object'] );
				break;
			}

			$_menu_items = array_map( 'wp_setup_nav_menu_item', array( $_object ) );
			$_menu_item = array_shift( $_menu_items );

			// Restore the missing menu item properties
			$menu_item_data['menu-item-description'] = $_menu_item->description;
		}

		$menu_items_data[] = $menu_item_data;
	}

	$item_ids = wp_save_nav_menu_items( 0, $menu_items_data );
	if ( is_wp_error( $item_ids ) )
		wp_die( 0 );

	$menu_items = array();

	foreach ( (array) $item_ids as $menu_item_id ) {
		$menu_obj = get_post( $menu_item_id );
		if ( ! empty( $menu_obj->ID ) ) {
			$menu_obj = wp_setup_nav_menu_item( $menu_obj );
			$menu_obj->label = $menu_obj->title; // don't show "(pending)" in ajax-added items
			$menu_items[] = $menu_obj;
		}
	}

	$walker_class_name = apply_filters( 'wp_edit_nav_menu_walker', 'Walker_Nav_Menu_Edit', $_POST['menu'] );

	if ( ! class_exists( $walker_class_name ) )
		wp_die( 0 );

	if ( ! empty( $menu_items ) ) {
		$args = array(
			'after' => '',
			'before' => '',
			'link_after' => '',
			'link_before' => '',
			'walker' => new $walker_class_name,
		);
		echo walk_nav_menu_tree( $menu_items, 0, (object) $args );
	}
	wp_die();
}

function wp_ajax_add_meta() {
	check_ajax_referer( 'add-meta', '_ajax_nonce-add-meta' );
	$c = 0;
	$pid = (int) $_POST['post_id'];
	$post = get_post( $pid );

	if ( isset($_POST['metakeyselect']) || isset($_POST['metakeyinput']) ) {
		if ( !current_user_can( 'edit_post', $pid ) )
			wp_die( -1 );
		if ( isset($_POST['metakeyselect']) && '#NONE#' == $_POST['metakeyselect'] && empty($_POST['metakeyinput']) )
			wp_die( 1 );
		if ( $post->post_status == 'auto-draft' ) {
			$save_POST = $_POST; // Backup $_POST
			$_POST = array(); // Make it empty for edit_post()
			$_POST['action'] = 'draft'; // Warning fix
			$_POST['post_ID'] = $pid;
			$_POST['post_type'] = $post->post_type;
			$_POST['post_status'] = 'draft';
			$now = current_time('timestamp', 1);
			$_POST['post_title'] = sprintf( __( 'Draft created on %1$s at %2$s' ), date( get_option( 'date_format' ), $now ), date( get_option( 'time_format' ), $now ) );

			if ( $pid = edit_post() ) {
				if ( is_wp_error( $pid ) ) {
					$x = new WP_Ajax_Response( array(
						'what' => 'meta',
						'data' => $pid
					) );
					$x->send();
				}
				$_POST = $save_POST; // Now we can restore original $_POST again
				if ( !$mid = add_meta( $pid ) )
					wp_die( __( 'Please provide a custom field value.' ) );
			} else {
				wp_die( 0 );
			}
		} else if ( !$mid = add_meta( $pid ) ) {
			wp_die( __( 'Please provide a custom field value.' ) );
		}

		$meta = get_metadata_by_mid( 'post', $mid );
		$pid = (int) $meta->post_id;
		$meta = get_object_vars( $meta );
		$x = new WP_Ajax_Response( array(
			'what' => 'meta',
			'id' => $mid,
			'data' => _list_meta_row( $meta, $c ),
			'position' => 1,
			'supplemental' => array('postid' => $pid)
		) );
	} else { // Update?
		$mid = (int) key( $_POST['meta'] );
		$key = wp_unslash( $_POST['meta'][$mid]['key'] );
		$value = wp_unslash( $_POST['meta'][$mid]['value'] );
		if ( '' == trim($key) )
			wp_die( __( 'Please provide a custom field name.' ) );
		if ( '' == trim($value) )
			wp_die( __( 'Please provide a custom field value.' ) );
		if ( ! $meta = get_metadata_by_mid( 'post', $mid ) )
			wp_die( 0 ); // if meta doesn't exist
		if ( is_protected_meta( $meta->meta_key, 'post' ) || is_protected_meta( $key, 'post' ) ||
			! current_user_can( 'edit_post_meta', $meta->post_id, $meta->meta_key ) ||
			! current_user_can( 'edit_post_meta', $meta->post_id, $key ) )
			wp_die( -1 );
		if ( $meta->meta_value != $value || $meta->meta_key != $key ) {
			if ( !$u = update_metadata_by_mid( 'post', $mid, $value, $key ) )
				wp_die( 0 ); // We know meta exists; we also know it's unchanged (or DB error, in which case there are bigger problems).
		}

		$x = new WP_Ajax_Response( array(
			'what' => 'meta',
			'id' => $mid, 'old_id' => $mid,
			'data' => _list_meta_row( array(
				'meta_key' => $key,
				'meta_value' => $value,
				'meta_id' => $mid
			), $c ),
			'position' => 0,
			'supplemental' => array('postid' => $meta->post_id)
		) );
	}
	$x->send();
}

function wp_ajax_add_user( $action ) {
	global $wp_list_table;
	if ( empty( $action ) )
		$action = 'add-user';

	check_ajax_referer( $action );
	if ( ! current_user_can('create_users') )
		wp_die( -1 );
	if ( ! $user_id = edit_user() ) {
		wp_die( 0 );
	} elseif ( is_wp_error( $user_id ) ) {
		$x = new WP_Ajax_Response( array(
			'what' => 'user',
			'id' => $user_id
		) );
		$x->send();
	}
	$user_object = get_userdata( $user_id );

	$wp_list_table = _get_list_table('WP_Users_List_Table');

	$role = current( $user_object->roles );

	$x = new WP_Ajax_Response( array(
		'what' => 'user',
		'id' => $user_id,
		'data' => $wp_list_table->single_row( $user_object, '', $role ),
		'supplemental' => array(
			'show-link' => sprintf(__( 'User <a href="#%s">%s</a> added' ), "user-$user_id", $user_object->user_login),
			'role' => $role,
		)
	) );
	$x->send();
}

function wp_ajax_autosave() {
	define( 'DOING_AUTOSAVE', true );

	$nonce_age = check_ajax_referer( 'autosave', 'autosavenonce' );

	$_POST['post_category'] = explode(",", $_POST['catslist']);
	if ( $_POST['post_type'] == 'page' || empty($_POST['post_category']) )
		unset($_POST['post_category']);

	$data = '';
	$supplemental = array();
	$id = $revision_id = 0;

	$post_id = (int) $_POST['post_id'];
	$_POST['ID'] = $_POST['post_ID'] = $post_id;
	$post = get_post($post_id);
	if ( 'auto-draft' == $post->post_status )
		$_POST['post_status'] = 'draft';

	if ( 'page' == $post->post_type ) {
		if ( !current_user_can('edit_page', $post->ID) )
			wp_die( __( 'You are not allowed to edit this page.' ) );
	} else {
		if ( !current_user_can('edit_post', $post->ID) )
			wp_die( __( 'You are not allowed to edit this post.' ) );
	}

	if ( ! empty( $_POST['autosave'] ) ) {
		// Drafts and auto-drafts are just overwritten by autosave for the same user
		if ( get_current_user_id() == $post->post_author && ( 'auto-draft' == $post->post_status || 'draft' == $post->post_status ) ) {
			$id = edit_post();
		} else { // Non drafts are not overwritten. The autosave is stored in a special post revision for each user.
			$revision_id = wp_create_post_autosave( $post->ID );
			if ( is_wp_error($revision_id) )
				$id = $revision_id;
			else
				$id = $post->ID;
		}

		if ( is_wp_error($id) ) {
			// is_wp_error($id) overwrites $data in WP_Ajax_Response but no point in doing wp_create_nonce('update-post_' . $id) below
			// todo: Needs review. The errors generated in WP_Ajax_Response and parsed with wpAjax.parseAjaxResponse() haven't been used for many years.
			$data = $id;
			$id = 0;
		} else {
			/* translators: draft saved date format, see http://php.net/date */
			$draft_saved_date_format = __('g:i:s a');
			/* translators: %s: date and time */
			$data = sprintf( __('Draft saved at %s.'), date_i18n( $draft_saved_date_format ) );
		}
	} else {
		if ( ! empty( $_POST['auto_draft'] ) )
			$id = 0; // This tells us it didn't actually save
		else
			$id = $post->ID;
	}

	if ( $nonce_age == 2 ) {
		$supplemental['replace-autosavenonce'] = wp_create_nonce('autosave');
		$supplemental['replace-getpermalinknonce'] = wp_create_nonce('getpermalink');
		$supplemental['replace-samplepermalinknonce'] = wp_create_nonce('samplepermalink');
		$supplemental['replace-closedpostboxesnonce'] = wp_create_nonce('closedpostboxes');
		$supplemental['replace-_ajax_linking_nonce'] = wp_create_nonce( 'internal-linking' );
		if ( $id )
			$supplemental['replace-_wpnonce'] = wp_create_nonce('update-post_' . $id);
	}

	$x = new WP_Ajax_Response( array(
		'what' => 'autosave',
		'id' => $id,
		'data' => $id ? $data : '',
		'supplemental' => $supplemental
	) );
	$x->send();
}

function wp_ajax_closed_postboxes() {
	check_ajax_referer( 'closedpostboxes', 'closedpostboxesnonce' );
	$closed = isset( $_POST['closed'] ) ? explode( ',', $_POST['closed']) : array();
	$closed = array_filter($closed);

	$hidden = isset( $_POST['hidden'] ) ? explode( ',', $_POST['hidden']) : array();
	$hidden = array_filter($hidden);

	$page = isset( $_POST['page'] ) ? $_POST['page'] : '';

	if ( $page != sanitize_key( $page ) )
		wp_die( 0 );

	if ( ! $user = wp_get_current_user() )
		wp_die( -1 );

	if ( is_array($closed) )
		update_user_option($user->ID, "closedpostboxes_$page", $closed, true);

	if ( is_array($hidden) ) {
		$hidden = array_diff( $hidden, array('submitdiv', 'linksubmitdiv', 'manage-menu', 'create-menu') ); // postboxes that are always shown
		update_user_option($user->ID, "metaboxhidden_$page", $hidden, true);
	}

	wp_die( 1 );
}

function wp_ajax_hidden_columns() {
	check_ajax_referer( 'screen-options-nonce', 'screenoptionnonce' );
	$hidden = isset( $_POST['hidden'] ) ? $_POST['hidden'] : '';
	$hidden = explode( ',', $_POST['hidden'] );
	$page = isset( $_POST['page'] ) ? $_POST['page'] : '';

	if ( $page != sanitize_key( $page ) )
		wp_die( 0 );

	if ( ! $user = wp_get_current_user() )
		wp_die( -1 );

	if ( is_array($hidden) )
		update_user_option($user->ID, "manage{$page}columnshidden", $hidden, true);

	wp_die( 1 );
}

function wp_ajax_update_welcome_panel() {
	check_ajax_referer( 'welcome-panel-nonce', 'welcomepanelnonce' );

	if ( ! current_user_can( 'edit_theme_options' ) )
		wp_die( -1 );

	update_user_meta( get_current_user_id(), 'show_welcome_panel', empty( $_POST['visible'] ) ? 0 : 1 );

	wp_die( 1 );
}

function wp_ajax_menu_get_metabox() {
	if ( ! current_user_can( 'edit_theme_options' ) )
		wp_die( -1 );

	require_once ABSPATH . 'wp-admin/includes/nav-menu.php';

	if ( isset( $_POST['item-type'] ) && 'post_type' == $_POST['item-type'] ) {
		$type = 'posttype';
		$callback = 'wp_nav_menu_item_post_type_meta_box';
		$items = (array) get_post_types( array( 'show_in_nav_menus' => true ), 'object' );
	} elseif ( isset( $_POST['item-type'] ) && 'taxonomy' == $_POST['item-type'] ) {
		$type = 'taxonomy';
		$callback = 'wp_nav_menu_item_taxonomy_meta_box';
		$items = (array) get_taxonomies( array( 'show_ui' => true ), 'object' );
	}

	if ( ! empty( $_POST['item-object'] ) && isset( $items[$_POST['item-object']] ) ) {
		$item = apply_filters( 'nav_menu_meta_box_object', $items[ $_POST['item-object'] ] );
		ob_start();
		call_user_func_array($callback, array(
			null,
			array(
				'id' => 'add-' . $item->name,
				'title' => $item->labels->name,
				'callback' => $callback,
				'args' => $item,
			)
		));

		$markup = ob_get_clean();

		echo json_encode(array(
			'replace-id' => $type . '-' . $item->name,
			'markup' => $markup,
		));
	}

	wp_die();
}

function wp_ajax_wp_link_ajax() {
	check_ajax_referer( 'internal-linking', '_ajax_linking_nonce' );

	$args = array();

	if ( isset( $_POST['search'] ) )
		$args['s'] = wp_unslash( $_POST['search'] );
	$args['pagenum'] = ! empty( $_POST['page'] ) ? absint( $_POST['page'] ) : 1;

	require(ABSPATH . WPINC . '/class-wp-editor.php');
	$results = _WP_Editors::wp_link_query( $args );

	if ( ! isset( $results ) )
		wp_die( 0 );

	echo json_encode( $results );
	echo "\n";

	wp_die();
}

function wp_ajax_menu_locations_save() {
	if ( ! current_user_can( 'edit_theme_options' ) )
		wp_die( -1 );
	check_ajax_referer( 'add-menu_item', 'menu-settings-column-nonce' );
	if ( ! isset( $_POST['menu-locations'] ) )
		wp_die( 0 );
	set_theme_mod( 'nav_menu_locations', array_map( 'absint', $_POST['menu-locations'] ) );
	wp_die( 1 );
}

function wp_ajax_meta_box_order() {
	check_ajax_referer( 'meta-box-order' );
	$order = isset( $_POST['order'] ) ? (array) $_POST['order'] : false;
	$page_columns = isset( $_POST['page_columns'] ) ? $_POST['page_columns'] : 'auto';

	if ( $page_columns != 'auto' )
		$page_columns = (int) $page_columns;

	$page = isset( $_POST['page'] ) ? $_POST['page'] : '';

	if ( $page != sanitize_key( $page ) )
		wp_die( 0 );

	if ( ! $user = wp_get_current_user() )
		wp_die( -1 );

	if ( $order )
		update_user_option($user->ID, "meta-box-order_$page", $order, true);

	if ( $page_columns )
		update_user_option($user->ID, "screen_layout_$page", $page_columns, true);

	wp_die( 1 );
}

function wp_ajax_menu_quick_search() {
	if ( ! current_user_can( 'edit_theme_options' ) )
		wp_die( -1 );

	require_once ABSPATH . 'wp-admin/includes/nav-menu.php';

	_wp_ajax_menu_quick_search( $_POST );

	wp_die();
}

function wp_ajax_get_permalink() {
	check_ajax_referer( 'getpermalink', 'getpermalinknonce' );
	$post_id = isset($_POST['post_id'])? intval($_POST['post_id']) : 0;
	wp_die( add_query_arg( array( 'preview' => 'true' ), get_permalink( $post_id ) ) );
}

function wp_ajax_sample_permalink() {
	check_ajax_referer( 'samplepermalink', 'samplepermalinknonce' );
	$post_id = isset($_POST['post_id'])? intval($_POST['post_id']) : 0;
	$title = isset($_POST['new_title'])? $_POST['new_title'] : '';
	$slug = isset($_POST['new_slug'])? $_POST['new_slug'] : null;
	wp_die( get_sample_permalink_html( $post_id, $title, $slug ) );
}

function wp_ajax_inline_save() {
	global $wp_list_table;

	check_ajax_referer( 'inlineeditnonce', '_inline_edit' );

	if ( ! isset($_POST['post_ID']) || ! ( $post_ID = (int) $_POST['post_ID'] ) )
		wp_die();

	if ( 'page' == $_POST['post_type'] ) {
		if ( ! current_user_can( 'edit_page', $post_ID ) )
			wp_die( __( 'You are not allowed to edit this page.' ) );
	} else {
		if ( ! current_user_can( 'edit_post', $post_ID ) )
			wp_die( __( 'You are not allowed to edit this post.' ) );
	}

	if ( $last = wp_check_post_lock( $post_ID ) ) {
		$last_user = get_userdata( $last );
		$last_user_name = $last_user ? $last_user->display_name : __( 'Someone' );
		printf( $_POST['post_type'] == 'page' ? __( 'Saving is disabled: %s is currently editing this page.' ) : __( 'Saving is disabled: %s is currently editing this post.' ),	esc_html( $last_user_name ) );
		wp_die();
	}

	$data = &$_POST;

	$post = get_post( $post_ID, ARRAY_A );
	$post = wp_slash($post); //since it is from db

	$data['content'] = $post['post_content'];
	$data['excerpt'] = $post['post_excerpt'];

	// rename
	$data['user_ID'] = $GLOBALS['user_ID'];

	if ( isset($data['post_parent']) )
		$data['parent_id'] = $data['post_parent'];

	// status
	if ( isset($data['keep_private']) && 'private' == $data['keep_private'] )
		$data['post_status'] = 'private';
	else
		$data['post_status'] = $data['_status'];

	if ( empty($data['comment_status']) )
		$data['comment_status'] = 'closed';
	if ( empty($data['ping_status']) )
		$data['ping_status'] = 'closed';

	// update the post
	edit_post();

	$wp_list_table = _get_list_table( 'WP_Posts_List_Table', array( 'screen' => $_POST['screen'] ) );

	$mode = $_POST['post_view'];

	$level = 0;
	$request_post = array( get_post( $_POST['post_ID'] ) );
	$parent = $request_post[0]->post_parent;

	while ( $parent > 0 ) {
		$parent_post = get_post( $parent );
		$parent = $parent_post->post_parent;
		$level++;
	}

	$wp_list_table->display_rows( array( get_post( $_POST['post_ID'] ) ), $level );

	wp_die();
}

function wp_ajax_inline_save_tax() {
	global $wp_list_table;

	check_ajax_referer( 'taxinlineeditnonce', '_inline_edit' );

	$taxonomy = sanitize_key( $_POST['taxonomy'] );
	$tax = get_taxonomy( $taxonomy );
	if ( ! $tax )
		wp_die( 0 );

	if ( ! current_user_can( $tax->cap->edit_terms ) )
		wp_die( -1 );

	$wp_list_table = _get_list_table( 'WP_Terms_List_Table', array( 'screen' => 'edit-' . $taxonomy ) );

	if ( ! isset($_POST['tax_ID']) || ! ( $id = (int) $_POST['tax_ID'] ) )
		wp_die( -1 );

	$tag = get_term( $id, $taxonomy );
	$_POST['description'] = $tag->description;

	$updated = wp_update_term($id, $taxonomy, $_POST);
	if ( $updated && !is_wp_error($updated) ) {
		$tag = get_term( $updated['term_id'], $taxonomy );
		if ( !$tag || is_wp_error( $tag ) ) {
			if ( is_wp_error($tag) && $tag->get_error_message() )
				wp_die( $tag->get_error_message() );
			wp_die( __( 'Item not updated.' ) );
		}
	} else {
		if ( is_wp_error($updated) && $updated->get_error_message() )
			wp_die( $updated->get_error_message() );
		wp_die( __( 'Item not updated.' ) );
	}
	$level = 0;
	$parent = $tag->parent;
	while ( $parent > 0 ) {
		$parent_tag = get_term( $parent, $taxonomy );
		$parent = $parent_tag->parent;
		$level++;
	}
	echo $wp_list_table->single_row( $tag, $level );
	wp_die();
}

function wp_ajax_find_posts() {
	global $wpdb;

	check_ajax_referer( 'find-posts' );

	$post_types = get_post_types( array( 'public' => true ), 'objects' );
	unset( $post_types['attachment'] );

	$s = wp_unslash( $_POST['ps'] );
	$searchand = $search = '';
	$args = array(
		'post_type' => array_keys( $post_types ),
		'post_status' => 'any',
		'posts_per_page' => 50,
	);
	if ( '' !== $s )
		$args['s'] = $s;

	$posts = get_posts( $args );

	if ( ! $posts )
		wp_die( __('No items found.') );

	$html = '<table class="widefat" cellspacing="0"><thead><tr><th class="found-radio"><br /></th><th>'.__('Title').'</th><th class="no-break">'.__('Type').'</th><th class="no-break">'.__('Date').'</th><th class="no-break">'.__('Status').'</th></tr></thead><tbody>';
	foreach ( $posts as $post ) {
		$title = trim( $post->post_title ) ? $post->post_title : __( '(no title)' );

		switch ( $post->post_status ) {
			case 'publish' :
			case 'private' :
				$stat = __('Published');
				break;
			case 'future' :
				$stat = __('Scheduled');
				break;
			case 'pending' :
				$stat = __('Pending Review');
				break;
			case 'draft' :
				$stat = __('Draft');
				break;
		}

		if ( '0000-00-00 00:00:00' == $post->post_date ) {
			$time = '';
		} else {
			/* translators: date format in table columns, see http://php.net/date */
			$time = mysql2date(__('Y/m/d'), $post->post_date);
		}

		$html .= '<tr class="found-posts"><td class="found-radio"><input type="radio" id="found-'.$post->ID.'" name="found_post_id" value="' . esc_attr($post->ID) . '"></td>';
		$html .= '<td><label for="found-'.$post->ID.'">' . esc_html( $title ) . '</label></td><td class="no-break">' . esc_html( $post_types[$post->post_type]->labels->singular_name ) . '</td><td class="no-break">'.esc_html( $time ) . '</td><td class="no-break">' . esc_html( $stat ). ' </td></tr>' . "\n\n";
	}

	$html .= '</tbody></table>';

	$x = new WP_Ajax_Response();
	$x->add( array(
		'data' => $html
	));
	$x->send();
}

function wp_ajax_widgets_order() {
	check_ajax_referer( 'save-sidebar-widgets', 'savewidgets' );

	if ( !current_user_can('edit_theme_options') )
		wp_die( -1 );

	unset( $_POST['savewidgets'], $_POST['action'] );

	// save widgets order for all sidebars
	if ( is_array($_POST['sidebars']) ) {
		$sidebars = array();
		foreach ( $_POST['sidebars'] as $key => $val ) {
			$sb = array();
			if ( !empty($val) ) {
				$val = explode(',', $val);
				foreach ( $val as $k => $v ) {
					if ( strpos($v, 'widget-') === false )
						continue;

					$sb[$k] = substr($v, strpos($v, '_') + 1);
				}
			}
			$sidebars[$key] = $sb;
		}
		wp_set_sidebars_widgets($sidebars);
		wp_die( 1 );
	}

	wp_die( -1 );
}

function wp_ajax_save_widget() {
	global $wp_registered_widgets, $wp_registered_widget_controls, $wp_registered_widget_updates;

	check_ajax_referer( 'save-sidebar-widgets', 'savewidgets' );

	if ( !current_user_can('edit_theme_options') || !isset($_POST['id_base']) )
		wp_die( -1 );

	unset( $_POST['savewidgets'], $_POST['action'] );

	do_action('load-widgets.php');
	do_action('widgets.php');
	do_action('sidebar_admin_setup');

	$id_base = $_POST['id_base'];
	$widget_id = $_POST['widget-id'];
	$sidebar_id = $_POST['sidebar'];
	$multi_number = !empty($_POST['multi_number']) ? (int) $_POST['multi_number'] : 0;
	$settings = isset($_POST['widget-' . $id_base]) && is_array($_POST['widget-' . $id_base]) ? $_POST['widget-' . $id_base] : false;
	$error = '<p>' . __('An error has occurred. Please reload the page and try again.') . '</p>';

	$sidebars = wp_get_sidebars_widgets();
	$sidebar = isset($sidebars[$sidebar_id]) ? $sidebars[$sidebar_id] : array();

	// delete
	if ( isset($_POST['delete_widget']) && $_POST['delete_widget'] ) {

		if ( !isset($wp_registered_widgets[$widget_id]) )
			wp_die( $error );

		$sidebar = array_diff( $sidebar, array($widget_id) );
		$_POST = array('sidebar' => $sidebar_id, 'widget-' . $id_base => array(), 'the-widget-id' => $widget_id, 'delete_widget' => '1');
	} elseif ( $settings && preg_match( '/__i__|%i%/', key($settings) ) ) {
		if ( !$multi_number )
			wp_die( $error );

		$_POST['widget-' . $id_base] = array( $multi_number => array_shift($settings) );
		$widget_id = $id_base . '-' . $multi_number;
		$sidebar[] = $widget_id;
	}
	$_POST['widget-id'] = $sidebar;

	foreach ( (array) $wp_registered_widget_updates as $name => $control ) {

		if ( $name == $id_base ) {
			if ( !is_callable( $control['callback'] ) )
				continue;

			ob_start();
				call_user_func_array( $control['callback'], $control['params'] );
			ob_end_clean();
			break;
		}
	}

	if ( isset($_POST['delete_widget']) && $_POST['delete_widget'] ) {
		$sidebars[$sidebar_id] = $sidebar;
		wp_set_sidebars_widgets($sidebars);
		echo "deleted:$widget_id";
		wp_die();
	}

	if ( !empty($_POST['add_new']) )
		wp_die();

	if ( $form = $wp_registered_widget_controls[$widget_id] )
		call_user_func_array( $form['callback'], $form['params'] );

	wp_die();
}

function wp_ajax_upload_attachment() {
	check_ajax_referer( 'media-form' );

	if ( ! current_user_can( 'upload_files' ) )
		wp_die();

	if ( isset( $_REQUEST['post_id'] ) ) {
		$post_id = $_REQUEST['post_id'];
		if ( ! current_user_can( 'edit_post', $post_id ) )
			wp_die();
	} else {
		$post_id = null;
	}

	$post_data = isset( $_REQUEST['post_data'] ) ? $_REQUEST['post_data'] : array();

	// If the context is custom header or background, make sure the uploaded file is an image.
	if ( isset( $post_data['context'] ) && in_array( $post_data['context'], array( 'custom-header', 'custom-background' ) ) ) {
		$wp_filetype = wp_check_filetype_and_ext( $_FILES['async-upload']['tmp_name'], $_FILES['async-upload']['name'], false );
		if ( ! wp_match_mime_types( 'image', $wp_filetype['type'] ) ) {
			echo json_encode( array(
				'success' => false,
				'data'    => array(
					'message'  => __( 'The uploaded file is not a valid image. Please try again.' ),
					'filename' => $_FILES['async-upload']['name'],
				)
			) );

			wp_die();
		}
	}

	$attachment_id = media_handle_upload( 'async-upload', $post_id, $post_data );

	if ( is_wp_error( $attachment_id ) ) {
		echo json_encode( array(
			'success' => false,
			'data'    => array(
				'message'  => $attachment_id->get_error_message(),
				'filename' => $_FILES['async-upload']['name'],
			)
		) );

		wp_die();
	}

	if ( isset( $post_data['context'] ) && isset( $post_data['theme'] ) ) {
		if ( 'custom-background' === $post_data['context'] )
			update_post_meta( $attachment_id, '_wp_attachment_is_custom_background', $post_data['theme'] );

		if ( 'custom-header' === $post_data['context'] )
			update_post_meta( $attachment_id, '_wp_attachment_is_custom_header', $post_data['theme'] );
	}

	if ( ! $attachment = wp_prepare_attachment_for_js( $attachment_id ) )
		wp_die();

	echo json_encode( array(
		'success' => true,
		'data'    => $attachment,
	) );

	wp_die();
}

function wp_ajax_image_editor() {
	$attachment_id = intval($_POST['postid']);
	if ( empty($attachment_id) || !current_user_can('edit_post', $attachment_id) )
		wp_die( -1 );

	check_ajax_referer( "image_editor-$attachment_id" );
	include_once( ABSPATH . 'wp-admin/includes/image-edit.php' );

	$msg = false;
	switch ( $_POST['do'] ) {
		case 'save' :
			$msg = wp_save_image($attachment_id);
			$msg = json_encode($msg);
			wp_die( $msg );
			break;
		case 'scale' :
			$msg = wp_save_image($attachment_id);
			break;
		case 'restore' :
			$msg = wp_restore_image($attachment_id);
			break;
	}

	wp_image_editor($attachment_id, $msg);
	wp_die();
}

function wp_ajax_set_post_thumbnail() {
	$json = ! empty( $_REQUEST['json'] ); // New-style request

	$post_ID = intval( $_POST['post_id'] );
	if ( ! current_user_can( 'edit_post', $post_ID ) )
		wp_die( -1 );

	$thumbnail_id = intval( $_POST['thumbnail_id'] );

	if ( $json )
		check_ajax_referer( "update-post_$post_ID" );
	else
		check_ajax_referer( "set_post_thumbnail-$post_ID" );

	if ( $thumbnail_id == '-1' ) {
		if ( delete_post_thumbnail( $post_ID ) ) {
			$return = _wp_post_thumbnail_html( null, $post_ID );
			$json ? wp_send_json_success( $return ) : wp_die( $return );
		} else {
			wp_die( 0 );
		}
	}

	if ( set_post_thumbnail( $post_ID, $thumbnail_id ) ) {
		$return = _wp_post_thumbnail_html( $thumbnail_id, $post_ID );
		$json ? wp_send_json_success( $return ) : wp_die( $return );
	}

	wp_die( 0 );
}

function wp_ajax_date_format() {
	wp_die( date_i18n( sanitize_option( 'date_format', $_POST['date'] ) ) );
}

function wp_ajax_time_format() {
	wp_die( date_i18n( sanitize_option( 'time_format', $_POST['date'] ) ) );
}

function wp_ajax_wp_fullscreen_save_post() {
	$post_id = isset( $_POST['post_ID'] ) ? (int) $_POST['post_ID'] : 0;

	$post = $post_type = null;

	if ( $post_id )
		$post = get_post( $post_id );

	if ( $post )
		$post_type = $post->post_type;
	elseif ( isset( $_POST['post_type'] ) && post_type_exists( $_POST['post_type'] ) )
		$post_type = $_POST['post_type'];

	check_ajax_referer('update-post_' . $post_id, '_wpnonce');

	$post_id = edit_post();

	if ( is_wp_error($post_id) ) {
		if ( $post_id->get_error_message() )
			$message = $post_id->get_error_message();
		else
			$message = __('Save failed');

		echo json_encode( array( 'message' => $message, 'last_edited' => '' ) );
		wp_die();
	} else {
		$message = __('Saved.');
	}

	if ( $post ) {
		$last_date = mysql2date( get_option('date_format'), $post->post_modified );
		$last_time = mysql2date( get_option('time_format'), $post->post_modified );
	} else {
		$last_date = date_i18n( get_option('date_format') );
		$last_time = date_i18n( get_option('time_format') );
	}

	if ( $last_id = get_post_meta($post_id, '_edit_last', true) ) {
		$last_user = get_userdata($last_id);
		$last_edited = sprintf( __('Last edited by %1$s on %2$s at %3$s'), esc_html( $last_user->display_name ), $last_date, $last_time );
	} else {
		$last_edited = sprintf( __('Last edited on %1$s at %2$s'), $last_date, $last_time );
	}

	echo json_encode( array( 'message' => $message, 'last_edited' => $last_edited ) );
	wp_die();
}

function wp_ajax_wp_remove_post_lock() {
	if ( empty( $_POST['post_ID'] ) || empty( $_POST['active_post_lock'] ) )
		wp_die( 0 );
	$post_id = (int) $_POST['post_ID'];
	if ( ! $post = get_post( $post_id ) )
		wp_die( 0 );

	check_ajax_referer( 'update-post_' . $post_id );

	if ( ! current_user_can( 'edit_post', $post_id ) )
		wp_die( -1 );

	$active_lock = array_map( 'absint', explode( ':', $_POST['active_post_lock'] ) );
	if ( $active_lock[1] != get_current_user_id() )
		wp_die( 0 );

	$new_lock = ( time() - apply_filters( 'wp_check_post_lock_window', 120 ) + 5 ) . ':' . $active_lock[1];
	update_post_meta( $post_id, '_edit_lock', $new_lock, implode( ':', $active_lock ) );
	wp_die( 1 );
}

function wp_ajax_dismiss_wp_pointer() {
	$pointer = $_POST['pointer'];
	if ( $pointer != sanitize_key( $pointer ) )
		wp_die( 0 );

//	check_ajax_referer( 'dismiss-pointer_' . $pointer );

	$dismissed = array_filter( explode( ',', (string) get_user_meta( get_current_user_id(), 'dismissed_wp_pointers', true ) ) );

	if ( in_array( $pointer, $dismissed ) )
		wp_die( 0 );

	$dismissed[] = $pointer;
	$dismissed = implode( ',', $dismissed );

	update_user_meta( get_current_user_id(), 'dismissed_wp_pointers', $dismissed );
	wp_die( 1 );
}

/**
 * Get an attachment.
 *
 * @since 3.5.0
 */
function wp_ajax_get_attachment() {
	if ( ! isset( $_REQUEST['id'] ) )
		wp_send_json_error();

	if ( ! $id = absint( $_REQUEST['id'] ) )
		wp_send_json_error();

	if ( ! $post = get_post( $id ) )
		wp_send_json_error();

	if ( 'attachment' != $post->post_type )
		wp_send_json_error();

	if ( ! current_user_can( 'upload_files' ) )
		wp_send_json_error();

	if ( ! $attachment = wp_prepare_attachment_for_js( $id ) )
		wp_send_json_error();

	wp_send_json_success( $attachment );
}

/**
 * Query for attachments.
 *
 * @since 3.5.0
 */
function wp_ajax_query_attachments() {
	if ( ! current_user_can( 'upload_files' ) )
		wp_send_json_error();

	$query = isset( $_REQUEST['query'] ) ? (array) $_REQUEST['query'] : array();
	$query = array_intersect_key( $query, array_flip( array(
		's', 'order', 'orderby', 'posts_per_page', 'paged', 'post_mime_type',
		'post_parent', 'post__in', 'post__not_in',
	) ) );

	$query['post_type'] = 'attachment';
	$query['post_status'] = 'inherit';
	if ( current_user_can( get_post_type_object( 'attachment' )->cap->read_private_posts ) )
		$query['post_status'] .= ',private';

	$query = new WP_Query( $query );

	$posts = array_map( 'wp_prepare_attachment_for_js', $query->posts );
	$posts = array_filter( $posts );

	wp_send_json_success( $posts );
}

/**
 * Save attachment attributes.
 *
 * @since 3.5.0
 */
function wp_ajax_save_attachment() {
	if ( ! isset( $_REQUEST['id'] ) || ! isset( $_REQUEST['changes'] ) )
		wp_send_json_error();

	if ( ! $id = absint( $_REQUEST['id'] ) )
		wp_send_json_error();

	check_ajax_referer( 'update-post_' . $id, 'nonce' );

	if ( ! current_user_can( 'edit_post', $id ) )
		wp_send_json_error();

	$changes = $_REQUEST['changes'];
	$post    = get_post( $id, ARRAY_A );

	if ( 'attachment' != $post['post_type'] )
		wp_send_json_error();

	if ( isset( $changes['title'] ) )
		$post['post_title'] = $changes['title'];

	if ( isset( $changes['caption'] ) )
		$post['post_excerpt'] = $changes['caption'];

	if ( isset( $changes['description'] ) )
		$post['post_content'] = $changes['description'];

	if ( isset( $changes['alt'] ) ) {
		$alt = wp_unslash( $changes['alt'] );
		if ( $alt != get_post_meta( $id, '_wp_attachment_image_alt', true ) ) {
			$alt = wp_strip_all_tags( $alt, true );
			update_post_meta( $id, '_wp_attachment_image_alt', wp_slash( $alt ) );
		}
	}

	wp_update_post( $post );
	wp_send_json_success();
}

/**
 * Save backwards compatible attachment attributes.
 *
 * @since 3.5.0
 */
function wp_ajax_save_attachment_compat() {
	if ( ! isset( $_REQUEST['id'] ) )
		wp_send_json_error();

	if ( ! $id = absint( $_REQUEST['id'] ) )
		wp_send_json_error();

	if ( empty( $_REQUEST['attachments'] ) || empty( $_REQUEST['attachments'][ $id ] ) )
		wp_send_json_error();
	$attachment_data = $_REQUEST['attachments'][ $id ];

	check_ajax_referer( 'update-post_' . $id, 'nonce' );

	if ( ! current_user_can( 'edit_post', $id ) )
		wp_send_json_error();

	$post = get_post( $id, ARRAY_A );

	if ( 'attachment' != $post['post_type'] )
		wp_send_json_error();

	$post = apply_filters( 'attachment_fields_to_save', $post, $attachment_data );

	if ( isset( $post['errors'] ) ) {
		$errors = $post['errors']; // @todo return me and display me!
		unset( $post['errors'] );
	}

	wp_update_post( $post );

	foreach ( get_attachment_taxonomies( $post ) as $taxonomy ) {
		if ( isset( $attachment_data[ $taxonomy ] ) )
			wp_set_object_terms( $id, array_map( 'trim', preg_split( '/,+/', $attachment_data[ $taxonomy ] ) ), $taxonomy, false );
	}

	if ( ! $attachment = wp_prepare_attachment_for_js( $id ) )
		wp_send_json_error();

	wp_send_json_success( $attachment );
}

function wp_ajax_save_attachment_order() {
	if ( ! isset( $_REQUEST['post_id'] ) )
		wp_send_json_error();

	if ( ! $post_id = absint( $_REQUEST['post_id'] ) )
		wp_send_json_error();

	if ( empty( $_REQUEST['attachments'] ) )
		wp_send_json_error();

	check_ajax_referer( 'update-post_' . $post_id, 'nonce' );

	$attachments = $_REQUEST['attachments'];

	if ( ! current_user_can( 'edit_post', $post_id ) )
		wp_send_json_error();

	$post = get_post( $post_id, ARRAY_A );

	foreach ( $attachments as $attachment_id => $menu_order ) {
		if ( ! current_user_can( 'edit_post', $attachment_id ) )
			continue;
		if ( ! $attachment = get_post( $attachment_id ) )
			continue;
		if ( 'attachment' != $attachment->post_type )
			continue;

		wp_update_post( array( 'ID' => $attachment_id, 'menu_order' => $menu_order ) );
	}

	wp_send_json_success();
}

/**
 * Generates the HTML to send an attachment to the editor.
 * Backwards compatible with the media_send_to_editor filter and the chain
 * of filters that follow.
 *
 * @since 3.5.0
 */
function wp_ajax_send_attachment_to_editor() {
	check_ajax_referer( 'media-send-to-editor', 'nonce' );

	$attachment = wp_unslash( $_POST['attachment'] );

	$id = intval( $attachment['id'] );

	if ( ! $post = get_post( $id ) )
		wp_send_json_error();

	if ( 'attachment' != $post->post_type )
		wp_send_json_error();

	if ( current_user_can( 'edit_post', $id ) ) {
		// If this attachment is unattached, attach it. Primarily a back compat thing.
		if ( 0 == $post->post_parent && $insert_into_post_id = intval( $_POST['post_id'] ) ) {
			wp_update_post( array( 'ID' => $id, 'post_parent' => $insert_into_post_id ) );
		}
	}

	$rel = $url = '';
	$html = $title = isset( $attachment['post_title'] ) ? $attachment['post_title'] : '';
	if ( ! empty( $attachment['url'] ) ) {
		$url = $attachment['url'];
		if ( strpos( $url, 'attachment_id') || get_attachment_link( $id ) == $url )
			$rel = ' rel="attachment wp-att-' . $id . '"';
		$html = '<a href="' . esc_url( $url ) . '"' . $rel . '>' . $html . '</a>';
	}

	remove_filter( 'media_send_to_editor', 'image_media_send_to_editor', 10, 3 );

	if ( 'image' === substr( $post->post_mime_type, 0, 5 ) ) {
		$align = isset( $attachment['align'] ) ? $attachment['align'] : 'none';
		$size = isset( $attachment['image-size'] ) ? $attachment['image-size'] : 'medium';
		$alt = isset( $attachment['image_alt'] ) ? $attachment['image_alt'] : '';
		$caption = isset( $attachment['post_excerpt'] ) ? $attachment['post_excerpt'] : '';
		$title = ''; // We no longer insert title tags into <img> tags, as they are redundant.
		$html = get_image_send_to_editor( $id, $caption, $title, $align, $url, (bool) $rel, $size, $alt );
	} elseif ( 'video' === substr( $post->post_mime_type, 0, 5 ) || 'audio' === substr( $post->post_mime_type, 0, 5 )  ) {
		$html = stripslashes_deep( $_POST['html'] );
	}

	$html = apply_filters( 'media_send_to_editor', $html, $id, $attachment );

	wp_send_json_success( $html );
}

/**
 * Generates the HTML to send a non-image embed link to the editor.
 *
 * Backwards compatible with the following filters:
 * - file_send_to_editor_url
 * - audio_send_to_editor_url
 * - video_send_to_editor_url
 *
 * @since 3.5.0
 */
function wp_ajax_send_link_to_editor() {
	check_ajax_referer( 'media-send-to-editor', 'nonce' );

	if ( ! $src = wp_unslash( $_POST['src'] ) )
		wp_send_json_error();

	if ( ! strpos( $src, '://' ) )
		$src = 'http://' . $src;

	if ( ! $src = esc_url_raw( $src ) )
		wp_send_json_error();

	if ( ! $title = trim( wp_unslash( $_POST['title'] ) ) )
		$title = wp_basename( $src );

	$html = '';
	if ( $title )
		$html = '<a href="' . esc_url( $src ) . '">' . $title . '</a>';

	// Figure out what filter to run:
	$type = 'file';
	if ( ( $ext = preg_replace( '/^.+?\.([^.]+)$/', '$1', $src ) ) && ( $ext_type = wp_ext2type( $ext ) )
		&& ( 'audio' == $ext_type || 'video' == $ext_type ) )
			$type = $ext_type;

	$html = apply_filters( $type . '_send_to_editor_url', $html, $src, $title );

	wp_send_json_success( $html );
}

function wp_ajax_heartbeat() {
	check_ajax_referer( 'heartbeat-nonce', '_nonce' );
	$response = array();

	// screen_id is the same as $current_screen->id and the JS global 'pagenow'
	if ( ! empty($_POST['screenid']) )
		$screen_id = sanitize_key($_POST['screenid']);
	else
		$screen_id = 'site';

	if ( ! empty($_POST['data']) ) {
		$data = (array) $_POST['data'];
		// todo: how much to sanitize and preset and what to leave to be accessed from $data or $_POST..?
		$user = wp_get_current_user();
		$data['user_id'] = $user->exists() ? $user->ID : 0;

		// todo: separate filters: 'heartbeat_[action]' so we call different callbacks only when there is data for them,
		// or all callbacks listen to one filter and run when there is something for them in $data?
		$response = apply_filters( 'heartbeat_received', $response, $data, $screen_id );
	}

	$response = apply_filters( 'heartbeat_send', $response, $screen_id );

	// Allow the transport to be replaced with long-polling easily
	do_action( 'heartbeat_tick', $response, $screen_id );

	// send the current time acording to the server
	$response['servertime'] = time();

	wp_send_json($response);
}

function wp_ajax_revisions_data() {
	check_ajax_referer( 'revisions-ajax-nonce', 'nonce' );

	$compare_to = ! empty( $_GET['compare_to'] ) ? absint( $_GET['compare_to'] ) : 0;
	$show_autosaves = ! empty( $_GET['show_autosaves'] );
	$show_split_view = ! empty( $_GET['show_split_view'] );
	$post_id = ! empty( $_GET['post_id'] ) ? absint( $_GET['post_id'] ) : 0;
	$right_handle_at = ! empty( $_GET['right_handle_at'] ) ? (int) $_GET['right_handle_at'] : 0;
	$left_handle_at = ! empty( $_GET['left_handle_at'] ) ? (int) $_GET['left_handle_at'] : 0;
	$single_revision_id = ! empty( $_GET['single_revision_id'] ) ? absint( $_GET['single_revision_id'] ) : 0;
	$compare_two_mode = (bool) $post_id;

	//
	//TODO: currently code returns all possible comparisons for the indicated 'compare_to' revision
	//however, the front end prevents users from pulling the right handle past the left or the left pass the right,
	//so only the possible diffs need be generated
	//
	$all_the_revisions = array();
	if ( ! $post_id )
		$post_id = $compare_to;

	if ( ! current_user_can( 'read_post', $post_id ) )
		continue;

	if ( ! $revisions = wp_get_post_revisions( $post_id ) )
		return;

	$left_revision = get_post( $compare_to );

	//single model fetch mode
	//return the diff of a single revision comparison
	if ( $single_revision_id ) {
		$right_revision = get_post( $single_revision_id );

		if ( ! $compare_to )
			$left_revision = get_post( $post_id );

		// make sure the right revision is the most recent
		if ( $compare_two_mode && $right_revision->ID < $left_revision->ID ) {
			$temp = $left_revision;
			$left_revision = $right_revision;
			$right_revision = $temp;
		}

		$lines_added = $lines_deleted = 0;
		$content = '';
		//compare from left to right, passed from application
		foreach ( array_keys( _wp_post_revision_fields() ) as $field ) {
			$left_content = apply_filters( "_wp_post_revision_field_$field", $left_revision->$field, $field, $left_revision, 'left' );
			$right_content = apply_filters( "_wp_post_revision_field_$field", $right_revision->$field, $field, $right_revision, 'right' );

			add_filter( "_wp_post_revision_field_$field", 'wp_kses_post' );

			$args = array();

			if ( $show_split_view )
				 $args = array( 'show_split_view' => true );

			// compare_to == 0 means first revision, so compare to a blank field to show whats changed
			$diff = wp_text_diff_with_count( ( 0 == $compare_to ) ? '' : $left_content, $right_content, $args );

			if ( isset( $diff[ 'html' ] ) )
				$content .= $diff[ 'html' ];

			if ( isset( $diff[ 'lines_added' ] ) )
				$lines_added = $lines_added + $diff[ 'lines_added' ];

			if ( isset( $diff[ 'lines_deleted' ] ) )
				$lines_deleted = $lines_deleted + $diff[ 'lines_deleted' ];
		}
		$content = '' == $content ? __( 'No difference' ) : $content;

		$all_the_revisions = array (
			'diff'          => $content,
			'lines_deleted' => $lines_deleted,
			'lines_added'   => $lines_added
		);

		echo json_encode( $all_the_revisions );
		exit();
	} //end single model fetch

	$count = -1;

	//reverse the list to start with oldes revision
	$revisions = array_reverse( $revisions );

	$previous_revision_id = 0;

	/* translators: revision date format, see http://php.net/date */
	$datef = _x( 'j F, Y @ G:i:s', 'revision date format');

	foreach ( $revisions as $revision ) :
		if ( ! $show_autosaves && wp_is_post_autosave( $revision ) )
			continue;

		$revision_from_date_author = '';
		$count++;
		// return blank data for diffs to the left of the left handle (for right handel model)
		// or to the right of the right handle (for left handel model)
		if ( ( 0 != $left_handle_at && $count < $left_handle_at ) ||
			 ( 0 != $right_handle_at && $count > ( $right_handle_at - 2 ) ) ) {
			$all_the_revisions[] = array (
				'ID' => $revision->ID,
			);
			continue;
		}

		if ( $compare_two_mode ) {
			$compare_to_gravatar = get_avatar( $left_revision->post_author, 24 );
			$compare_to_author = get_the_author_meta( 'display_name', $left_revision->post_author );
			$compare_to_date = date_i18n( $datef, strtotime( $left_revision->post_modified ) );

			$revision_from_date_author = sprintf(
				/* translators: post revision title: 1: author avatar, 2: author name, 3: time ago, 4: date */
				_x( '%1$s %2$s, %3$s ago (%4$s)', 'post revision title' ),
				$compare_to_gravatar,
				$compare_to_author,
				human_time_diff( strtotime( $left_revision->post_modified ), current_time( 'timestamp' ) ),
				$compare_to_date
			);
		}

		$gravatar = get_avatar( $revision->post_author, 24 );
		$author = get_the_author_meta( 'display_name', $revision->post_author );
		$date = date_i18n( $datef, strtotime( $revision->post_modified ) );
		$revision_date_author = sprintf(
			/* translators: post revision title: 1: author avatar, 2: author name, 3: time ago, 4: date */
			_x( '%1$s %2$s, %3$s ago (%4$s)', 'post revision title' ),
			$gravatar,
			$author,
			human_time_diff( strtotime( $revision->post_modified ), current_time( 'timestamp' ) ),
			$date
		);

		$autosavef = _x( '%1$s [Autosave]', 'post revision title extra' );
		$currentf  = _x( '%1$s [Current Revision]', 'post revision title extra' );

		if ( ! $post = get_post( $post_id ) )
			continue;

		if ( $left_revision->post_modified === $post->post_modified )
			$revision_from_date_author = sprintf( $currentf, $revision_from_date_author );
		elseif ( wp_is_post_autosave( $left_revision ) )
			$revision_from_date_author = sprintf( $autosavef, $revision_from_date_author );

		if ( $revision->post_modified === $post->post_modified )
			$revision_date_author = sprintf( $currentf, $revision_date_author );
		elseif ( wp_is_post_autosave( $revision ) )
			$revision_date_author = sprintf( $autosavef, $revision_date_author );

		/* translators: revision date short format, see http://php.net/date */
		$date_short_format = _x( 'j M @ G:i', 'revision date short format');
		$date_short = date_i18n( $date_short_format, strtotime( $revision->post_modified ) );

		$revision_date_author_short = sprintf(
			'%s <strong>%s</strong><br />%s',
			$gravatar,
			$author,
			$date_short
		);

		$restore_link = wp_nonce_url(
			add_query_arg(
				array( 'revision' => $revision->ID,
					'action' => 'restore' ),
					admin_url( 'revision.php' )
			),
			"restore-post_{$revision->ID}"
		);

		// if this is a left handled calculation swap data
		if ( 0 != $right_handle_at ) {
			$tmp = $revision_from_date_author;
			$revision_from_date_author = $revision_date_author;
			$revision_date_author = $tmp;
		}

		if ( ( $compare_two_mode || -1 !== $previous_revision_id ) ) {
			$all_the_revisions[] = array (
				'ID'                   => $revision->ID,
				'titleTo'              => $revision_date_author,
				'titleFrom'            => $revision_from_date_author,
				'titleTooltip'         => $revision_date_author_short,
				'restoreLink'          => urldecode( $restore_link ),
				'revision_toload'      => true,
				'previous_revision_id' => $previous_revision_id
			);
		}
		$previous_revision_id = $revision->ID;

	endforeach;

	echo json_encode( $all_the_revisions );
	exit();
}