+/**
+ * Creates autosave data for the specified post from $_POST data.
+ *
+ * @package WordPress
+ * @subpackage Post_Revisions
+ * @since 2.6.0
+ *
+ * @param mixed $post_data Associative array containing the post data or int post ID.
+ * @return mixed The autosave revision ID. WP_Error or 0 on error.
+ */
+function wp_create_post_autosave( $post_data ) {
+ if ( is_numeric( $post_data ) ) {
+ $post_id = $post_data;
+ $post_data = $_POST;
+ } else {
+ $post_id = (int) $post_data['post_ID'];
+ }
+
+ $post_data = _wp_translate_postdata( true, $post_data );
+ if ( is_wp_error( $post_data ) )
+ return $post_data;
+
+ $post_author = get_current_user_id();
+
+ // Store one autosave per author. If there is already an autosave, overwrite it.
+ if ( $old_autosave = wp_get_post_autosave( $post_id, $post_author ) ) {
+ $new_autosave = _wp_post_revision_data( $post_data, true );
+ $new_autosave['ID'] = $old_autosave->ID;
+ $new_autosave['post_author'] = $post_author;
+
+ // If the new autosave has the same content as the post, delete the autosave.
+ $post = get_post( $post_id );
+ $autosave_is_different = false;
+ foreach ( array_intersect( array_keys( $new_autosave ), array_keys( _wp_post_revision_fields( $post ) ) ) as $field ) {
+ if ( normalize_whitespace( $new_autosave[ $field ] ) != normalize_whitespace( $post->$field ) ) {
+ $autosave_is_different = true;
+ break;
+ }
+ }
+
+ if ( ! $autosave_is_different ) {
+ wp_delete_post_revision( $old_autosave->ID );
+ return 0;
+ }
+
+ /**
+ * Fires before an autosave is stored.
+ *
+ * @since 4.1.0
+ *
+ * @param array $new_autosave Post array - the autosave that is about to be saved.
+ */
+ do_action( 'wp_creating_autosave', $new_autosave );
+
+ return wp_update_post( $new_autosave );
+ }
+
+ // _wp_put_post_revision() expects unescaped.
+ $post_data = wp_unslash( $post_data );
+
+ // Otherwise create the new autosave as a special post revision
+ return _wp_put_post_revision( $post_data, true );
+}
+
+/**
+ * Save draft or manually autosave for showing preview.
+ *
+ * @package WordPress
+ * @since 2.7.0
+ *
+ * @return str URL to redirect to show the preview
+ */
+function post_preview() {
+
+ $post_ID = (int) $_POST['post_ID'];
+ $_POST['ID'] = $post_ID;
+
+ if ( ! $post = get_post( $post_ID ) ) {
+ wp_die( __( 'You are not allowed to edit this post.' ) );
+ }
+
+ if ( ! current_user_can( 'edit_post', $post->ID ) ) {
+ wp_die( __( 'You are not allowed to edit this post.' ) );
+ }
+
+ $is_autosave = false;
+
+ if ( ! wp_check_post_lock( $post->ID ) && get_current_user_id() == $post->post_author && ( 'draft' == $post->post_status || 'auto-draft' == $post->post_status ) ) {
+ $saved_post_id = edit_post();
+ } else {
+ $is_autosave = true;
+
+ if ( isset( $_POST['post_status'] ) && 'auto-draft' == $_POST['post_status'] )
+ $_POST['post_status'] = 'draft';
+
+ $saved_post_id = wp_create_post_autosave( $post->ID );
+ }
+
+ if ( is_wp_error( $saved_post_id ) )
+ wp_die( $saved_post_id->get_error_message() );
+
+ $query_args = array();
+
+ if ( $is_autosave && $saved_post_id ) {
+ $query_args['preview_id'] = $post->ID;
+ $query_args['preview_nonce'] = wp_create_nonce( 'post_preview_' . $post->ID );
+
+ if ( isset( $_POST['post_format'] ) )
+ $query_args['post_format'] = empty( $_POST['post_format'] ) ? 'standard' : sanitize_key( $_POST['post_format'] );
+ }
+
+ return get_preview_post_link( $post, $query_args );
+}
+
+/**
+ * Save a post submitted with XHR
+ *
+ * Intended for use with heartbeat and autosave.js
+ *
+ * @since 3.9.0
+ *
+ * @param array $post_data Associative array of the submitted post data.
+ * @return mixed The value 0 or WP_Error on failure. The saved post ID on success.
+ * The ID can be the draft post_id or the autosave revision post_id.
+ */
+function wp_autosave( $post_data ) {
+ // Back-compat
+ if ( ! defined( 'DOING_AUTOSAVE' ) )
+ define( 'DOING_AUTOSAVE', true );
+
+ $post_id = (int) $post_data['post_id'];
+ $post_data['ID'] = $post_data['post_ID'] = $post_id;
+
+ if ( false === wp_verify_nonce( $post_data['_wpnonce'], 'update-post_' . $post_id ) ) {
+ return new WP_Error( 'invalid_nonce', __( 'Error while saving.' ) );
+ }
+
+ $post = get_post( $post_id );
+
+ if ( ! current_user_can( 'edit_post', $post->ID ) ) {
+ return new WP_Error( 'edit_posts', __( 'You are not allowed to edit this item.' ) );
+ }
+
+ if ( 'auto-draft' == $post->post_status )
+ $post_data['post_status'] = 'draft';
+
+ if ( $post_data['post_type'] != 'page' && ! empty( $post_data['catslist'] ) )
+ $post_data['post_category'] = explode( ',', $post_data['catslist'] );
+
+ if ( ! wp_check_post_lock( $post->ID ) && get_current_user_id() == $post->post_author && ( 'auto-draft' == $post->post_status || 'draft' == $post->post_status ) ) {
+ // Drafts and auto-drafts are just overwritten by autosave for the same user if the post is not locked
+ return edit_post( wp_slash( $post_data ) );
+ } else {
+ // Non drafts or other users drafts are not overwritten. The autosave is stored in a special post revision for each user.
+ return wp_create_post_autosave( wp_slash( $post_data ) );
+ }
+}
+
+/**
+ * Redirect to previous page.
+ *
+ * @param int $post_id Optional. Post ID.
+ */
+function redirect_post($post_id = '') {
+ if ( isset($_POST['save']) || isset($_POST['publish']) ) {
+ $status = get_post_status( $post_id );
+
+ if ( isset( $_POST['publish'] ) ) {
+ switch ( $status ) {
+ case 'pending':
+ $message = 8;
+ break;
+ case 'future':
+ $message = 9;
+ break;
+ default:
+ $message = 6;
+ }
+ } else {
+ $message = 'draft' == $status ? 10 : 1;
+ }
+
+ $location = add_query_arg( 'message', $message, get_edit_post_link( $post_id, 'url' ) );
+ } elseif ( isset($_POST['addmeta']) && $_POST['addmeta'] ) {
+ $location = add_query_arg( 'message', 2, wp_get_referer() );
+ $location = explode('#', $location);
+ $location = $location[0] . '#postcustom';
+ } elseif ( isset($_POST['deletemeta']) && $_POST['deletemeta'] ) {
+ $location = add_query_arg( 'message', 3, wp_get_referer() );
+ $location = explode('#', $location);
+ $location = $location[0] . '#postcustom';
+ } else {
+ $location = add_query_arg( 'message', 4, get_edit_post_link( $post_id, 'url' ) );
+ }
+
+ /**
+ * Filter the post redirect destination URL.
+ *
+ * @since 2.9.0
+ *
+ * @param string $location The destination URL.
+ * @param int $post_id The post ID.
+ */
+ wp_redirect( apply_filters( 'redirect_post_location', $location, $post_id ) );
+ exit;
+}