PHP wp_get_post_autosave函数代码示例

/**
 * Get post option value from the database
 *
 * @param null|int $post_id
 * @param string|null $option_id Specific option id (accepts multikey). null - all options
 * @param null|mixed $default_value If no option found in the database, this value will be returned
 * @param null|bool $get_original_value Original value is that with no translations and other changes
 *
 * @return mixed|null
 */
function fw_get_db_post_option($post_id = null, $option_id = null, $default_value = null, $get_original_value = null)
{
    if (!$post_id) {
        /** @var WP_Post $post */
        global $post;
        if (!$post) {
            return $default_value;
        } else {
            $post_id = $post->ID;
        }
        /**
         * Check if is Preview and use the preview post_id instead of real/current post id
         *
         * Note: WordPress changes the global $post content on preview:
         * 1. https://github.com/WordPress/WordPress/blob/2096b451c704715db3c4faf699a1184260deade9/wp-includes/query.php#L3573-L3583
         * 2. https://github.com/WordPress/WordPress/blob/4a31dd6fe8b774d56f901a29e72dcf9523e9ce85/wp-includes/revision.php#L485-L528
         */
        if (is_preview()) {
            $preview = wp_get_post_autosave($post->ID);
            if (is_object($preview)) {
                $post_id = $preview->ID;
            }
        }
    }
    $option_id = 'fw_options' . ($option_id !== null ? '/' . $option_id : '');
    return FW_WP_Meta::get('post', $post_id, $option_id, $default_value, $get_original_value);
}

function acf_filter_post_id($post_id)
{
    // set post_id to global
    if (!$post_id) {
        global $post;
        if ($post) {
            $post_id = $post->ID;
        }
    }
    // allow for option == options
    if ($post_id == "option") {
        $post_id = "options";
    }
    /*
     *  Override for preview
     *  
     *  If the $_GET['preview_id'] is set, then the user wants to see the preview data.
     *  There is also the case of previewing a page with post_id = 1, but using get_field
     *  to load data from another post_id.
     *  In this case, we need to make sure that the autosave revision is actually related
     *  to the $post_id variable. If they match, then the autosave data will be used, otherwise, 
     *  the user wants to load data from a completely different post_id
     */
    if (isset($_GET['preview_id'])) {
        $autosave = wp_get_post_autosave($_GET['preview_id']);
        if ($autosave->post_parent == $post_id) {
            $post_id = $autosave->ID;
        }
    }
    // return
    return $post_id;
}

 function post_revisions()
 {
     global $post, $current_user, $role;
     if ($this->WikiHelper->is_wiki('front_end_check')) {
         $wpw_options = get_option('wpw_options');
         $revisions = get_posts('post_status=any&post_type=revision&post_parent=' . $post->ID . '&numberposts=' . $wpw_options['number_of_revisions']);
         //Most recent revision
         $date = date(__('m/d/y g:i a'), mktime($post->post_modified));
         $author = $this->WikiHelper->get_author($post);
         $latest_revision = sprintf(__('Latest revision (@ %1s by %2s)'), $post->post_modified, $author);
         $output = '<a href="' . get_permalink($post->ID) . '">' . $latest_revision . '</a><br />';
         //If we have revisions...
         if ($revisions) {
             //Loop through them!
             $count = 0;
             foreach ($revisions as $revision) {
                 if (@wp_get_post_autosave($post->ID)->ID != $revision->ID) {
                     $author = $this->WikiHelper->get_author($revision);
                     $date = date(__('m/d/y g:i a'), mktime($revision->post_modified));
                     $revision_title = sprintf(__('Revision @ %1s by %2s'), $date, $author);
                     $output .= '<a href="' . get_permalink($post->ID) . '?revision=' . $revision->ID . '">' . $revision_title . '</a><br />';
                     $count++;
                 }
             }
         }
         return $output;
     }
 }

 /**
  * Request handler for XML.
  */
 public function request_handler()
 {
     if (get_query_var('xml')) {
         // Sanitize our article ID
         $id = get_the_ID();
         // If we don't have an Article, get out
         if (empty($id)) {
             wp_die(__('No article found.', $this->i18n));
         }
         // If we're not debugging, turn off errors
         if (!$this->debug) {
             $display_errors = ini_get('display_errors');
             ini_set('display_errors', 0);
         }
         // Default Article
         $article = null;
         // If we're published, grab the published article
         if (!is_preview()) {
             $article = get_post($id);
         } else {
             if (is_preview() && current_user_can('edit_post', $id)) {
                 $article = get_post($id);
                 /* Drafts and sometimes pending statuses append a preview_id on the 
                 			end of the preview URL.  While we're building the XML download link
                 			we do a check for that, and set this query arg if the preview_id is
                 			present. */
                 if (isset($_GET['autosave'])) {
                     $article = wp_get_post_autosave($id);
                 }
             }
         }
         // Ensure we have an article
         if (empty($article)) {
             wp_die(__('Required article first.', $this->i18n));
         }
         // Get our XML ready and stored
         $this->generate_xml($article);
         // Send our headers
         if (!$_GET['screen']) {
             $this->set_headers($article);
         }
         // Send the file
         echo $this->xml;
         exit;
     }
 }

 public function &get($postID = false, $type = "post")
 {
     if (!$postID) {
         global $post;
         if ($post) {
             $postID = $post->ID;
             $type = $post->post_type;
         } else {
             return $this->empty;
         }
     }
     if (isset($this->cache[$postID])) {
         return $this->cache[$postID];
     }
     $db = false;
     if ($postID) {
         $metaID = $postID;
         if (!empty($this->preview) && $postID == $this->preview) {
             // preview mode so we use meta stored in the autosave
             $preview = wp_get_post_autosave($postID);
             if (!empty($preview->ID)) {
                 $metaID = $preview->ID;
             }
         }
         $db = maybe_unserialize(get_post_meta($metaID, PE_THEME_META, true));
     }
     if (!isset($this->defaults[$type])) {
         $this->getDefaultValues($type);
     }
     if ($db) {
         $cache = new stdClass();
         $empty = array();
         foreach ($this->keys[$type] as $key) {
             if (!isset($db->{$key})) {
                 $db->{$key} = array();
             }
             $cache->{$key} = (object) array_merge((array) $this->defaults[$type]->{$key}, (array) $db->{$key});
         }
     } else {
         $cache =& $this->defaults[$type];
     }
     if ($postID) {
         $this->cache[$postID] =& $cache;
     }
     return $cache;
 }

 /**
  * @param array $posts
  * @return array
  */
 public static function maybe_set_preview($posts)
 {
     if (is_array($posts) && isset($_GET['preview']) && $_GET['preview'] && isset($_GET['preview_id']) && $_GET['preview_id'] && current_user_can('edit_post', $_GET['preview_id'])) {
         // No need to check the nonce, that already happened in _show_post_preview on init
         $preview_id = $_GET['preview_id'];
         foreach ($posts as &$post) {
             if (is_object($post) && $post->ID == $preview_id) {
                 // Based on _set_preview( $post ), but adds import_custom
                 $preview = wp_get_post_autosave($preview_id);
                 if (is_object($preview)) {
                     $preview = sanitize_post($preview);
                     $post->post_content = $preview->post_content;
                     $post->post_title = $preview->post_title;
                     $post->post_excerpt = $preview->post_excerpt;
                     $post->import_custom($preview_id);
                     add_filter('get_the_terms', '_wp_preview_terms_filter', 10, 3);
                 }
             }
         }
     }
     return $posts;
 }

 /**
  * Update an autosave for a post.
  *
  * @param WP_REST_Request $request Full details about the request.
  * @return WP_Error|WP_REST_Response
  */
 public function update_item($request)
 {
     $parent = get_post($request['id']);
     $autosave = wp_get_post_autosave($parent->ID, get_current_user_id());
     $post_data = (array) $this->prepare_item_for_database($request);
     if (!$autosave) {
         $autosave_id = _wp_put_post_revision($post_data, true);
     } else {
         $post_data['ID'] = $autosave->ID;
         /**
          * 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', $post_data);
         wp_update_post($post_data);
         $autosave_id = $autosave->ID;
     }
     return $this->prepare_item_for_response(get_post($autosave_id), $request);
 }

 function callback($path = '', $blog_id = 0, $post_id = 0)
 {
     $blog_id = $this->api->switch_to_blog_and_validate_user($this->api->get_blog_id($blog_id));
     if (is_wp_error($blog_id)) {
         return $blog_id;
     }
     $post = get_post($post_id);
     if (!$post || is_wp_error($post)) {
         return new WP_Error('unknown_post', 'Unknown post', 404);
     }
     if (!current_user_can('edit_post', $post->ID)) {
         return new WP_Error('unauthorized', 'User cannot edit post', 403);
     }
     $autosave = wp_get_post_autosave($post->ID);
     if ($autosave) {
         $preview_url = add_query_arg('preview', 'true', get_permalink($post->ID));
         $nonce = wp_create_nonce('post_preview_' . $post->ID);
         $preview_url = add_query_arg(array('preview_id' => $auto_ID, 'preview_nonce' => $nonce), $preview_url);
         return array('ID' => $autosave->ID, 'author_ID' => $autosave->post_author, 'post_ID' => $autosave->post_parent, 'title' => $autosave->post_title, 'content' => $autosave->post_content, 'excerpt' => $autosave->post_excerpt, 'preview_URL' => $preview_url, 'modified' => $this->format_date($autosave->post_modified));
     } else {
         return new WP_Error('not_found', 'No autosaves exist for this post', 404);
     }
 }

/**
 * Creates autosave data for the specified post from $_POST data.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @uses _wp_translate_postdata()
 * @uses _wp_post_revision_fields()
 *
 * @return unknown
 */
function wp_create_post_autosave($post_id)
{
    $translated = _wp_translate_postdata(true);
    if (is_wp_error($translated)) {
        return $translated;
    }
    // Only store one autosave. If there is already an autosave, overwrite it.
    if ($old_autosave = wp_get_post_autosave($post_id)) {
        $new_autosave = _wp_post_revision_fields($_POST, true);
        $new_autosave['ID'] = $old_autosave->ID;
        $new_autosave['post_author'] = get_current_user_id();
        return wp_update_post($new_autosave);
    }
    // _wp_put_post_revision() expects unescaped.
    $_POST = stripslashes_deep($_POST);
    // Otherwise create the new autosave as a special post revision
    return _wp_put_post_revision($_POST, true);
}

/**
 * Get post option value from the database
 *
 * @param null|int $post_id
 * @param string|null $option_id Specific option id (accepts multikey). null - all options
 * @param null|mixed $default_value If no option found in the database, this value will be returned
 * @param null|bool $get_original_value Original value is that with no translations and other changes
 *
 * @return mixed|null
 */
function fw_get_db_post_option($post_id = null, $option_id = null, $default_value = null, $get_original_value = null)
{
    if (!$post_id) {
        /** @var WP_Post $post */
        global $post;
        if (!$post) {
            return $default_value;
        } else {
            $post_id = $post->ID;
        }
        /**
         * Check if is Preview and use the preview post_id instead of real/current post id
         *
         * Note: WordPress changes the global $post content on preview:
         * 1. https://github.com/WordPress/WordPress/blob/2096b451c704715db3c4faf699a1184260deade9/wp-includes/query.php#L3573-L3583
         * 2. https://github.com/WordPress/WordPress/blob/4a31dd6fe8b774d56f901a29e72dcf9523e9ce85/wp-includes/revision.php#L485-L528
         */
        if (is_preview() && is_object($preview = wp_get_post_autosave($post->ID))) {
            $post_id = $preview->ID;
        }
    }
    $post_type = get_post_type(($post_revision_id = wp_is_post_revision($post_id)) ? $post_revision_id : $post_id);
    /**
     * Before fw_db_option_storage_load() feature
     * there was possible to call fw_get_db_post_option() and it worked fine
     * but after v2.5.0 it's not possible anymore (it creates an infinite recursion)
     * but the Slider extension does that and maybe other extensions,
     * so the solution is to check if it is recursion, to not load the options array (disable the storage feature)
     */
    static $recursion = array();
    if (!isset($recursion[$post_type])) {
        $recursion[$post_type] = false;
    }
    if ($recursion[$post_type]) {
        /**
         * Allow known post types that sure don't have options with 'fw-storage' parameter
         */
        if (!in_array($post_type, array('fw-slider'))) {
            trigger_error('Infinite recursion detected in post type "' . $post_type . '" options caused by ' . __FUNCTION__ . '()', E_USER_WARNING);
        }
        $options = array();
    } else {
        $recursion[$post_type] = true;
        $options = fw_extract_only_options(fw()->theme->get_post_options($post_type));
        $recursion[$post_type] = false;
    }
    if ($option_id) {
        $option_id = explode('/', $option_id);
        // 'option_id/sub/keys'
        $_option_id = array_shift($option_id);
        // 'option_id'
        $sub_keys = implode('/', $option_id);
        // 'sub/keys'
        $option_id = $_option_id;
        unset($_option_id);
        $value = FW_WP_Meta::get('post', $post_id, 'fw_options/' . $option_id, null, $get_original_value);
        if (isset($options[$option_id])) {
            $value = fw()->backend->option_type($options[$option_id]['type'])->storage_load($option_id, $options[$option_id], $value, array('post-id' => $post_id));
        }
        if ($sub_keys) {
            return fw_akg($sub_keys, $value, $default_value);
        } else {
            return is_null($value) ? $default_value : $value;
        }
    } else {
        $value = FW_WP_Meta::get('post', $post_id, 'fw_options', $default_value, $get_original_value);
        if (!is_array($value)) {
            $value = array();
        }
        foreach ($options as $_option_id => $_option) {
            $value[$_option_id] = fw()->backend->option_type($_option['type'])->storage_load($_option_id, $_option, isset($value[$_option_id]) ? $value[$_option_id] : null, array('post-id' => $post_id));
        }
        return $value;
    }
}

/**
 * Creates autosave data for the specified post from $_POST data.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @uses _wp_translate_postdata()
 * @uses _wp_post_revision_fields()
 */
function wp_create_post_autosave($post_id)
{
    $translated = _wp_translate_postdata(true);
    if (is_wp_error($translated)) {
        return $translated;
    }
    // Only store one autosave.  If there is already an autosave, overwrite it.
    if ($old_autosave = wp_get_post_autosave($post_id)) {
        $new_autosave = _wp_post_revision_fields($_POST, true);
        $new_autosave['ID'] = $old_autosave->ID;
        return wp_update_post($new_autosave);
    }
    // Otherwise create the new autosave as a special post revision
    return _wp_put_post_revision($_POST, true);
}

//.........这里部分代码省略.........
             case 'publicize_URLs':
                 $publicize_URLs = array();
                 $publicize = get_post_meta($post->ID, 'publicize_results', true);
                 if ($publicize) {
                     foreach ($publicize as $service => $data) {
                         switch ($service) {
                             case 'twitter':
                                 foreach ($data as $datum) {
                                     $publicize_URLs[] = esc_url_raw("https://twitter.com/{$datum['user_id']}/status/{$datum['post_id']}");
                                 }
                                 break;
                             case 'fb':
                                 foreach ($data as $datum) {
                                     $publicize_URLs[] = esc_url_raw("https://www.facebook.com/permalink.php?story_fbid={$datum['post_id']}&id={$datum['user_id']}");
                                 }
                                 break;
                         }
                     }
                 }
                 $response[$key] = (array) $publicize_URLs;
                 break;
             case 'tags':
                 $response[$key] = array();
                 $terms = wp_get_post_tags($post->ID);
                 foreach ($terms as $term) {
                     if (!empty($term->name)) {
                         $response[$key][$term->name] = $this->format_taxonomy($term, 'post_tag', 'display');
                     }
                 }
                 $response[$key] = (object) $response[$key];
                 break;
             case 'categories':
                 $response[$key] = array();
                 $terms = wp_get_object_terms($post->ID, 'category', array('fields' => 'all'));
                 foreach ($terms as $term) {
                     if (!empty($term->name)) {
                         $response[$key][$term->name] = $this->format_taxonomy($term, 'category', 'display');
                     }
                 }
                 $response[$key] = (object) $response[$key];
                 break;
             case 'attachments':
                 $response[$key] = array();
                 $_attachments = new WP_Query(array('post_parent' => $post->ID, 'post_status' => 'inherit', 'post_type' => 'attachment', 'posts_per_page' => '20'));
                 foreach ($_attachments->posts as $attachment) {
                     $response[$key][$attachment->ID] = $this->get_media_item_v1_1($attachment->ID);
                 }
                 $response['attachment_count'] = $_attachments->found_posts;
                 $response[$key] = (object) $response[$key];
                 break;
             case 'metadata':
                 // (array|false)
                 $metadata = array();
                 foreach ((array) has_meta($post_id) as $meta) {
                     // Don't expose protected fields.
                     $show = false;
                     if ($this->is_metadata_public($meta['meta_key'])) {
                         $show = true;
                     }
                     if (current_user_can('edit_post_meta', $post_id, $meta['meta_key'])) {
                         $show = true;
                     }
                     if (!$show) {
                         continue;
                     }
                     $metadata[] = array('id' => $meta['meta_id'], 'key' => $meta['meta_key'], 'value' => maybe_unserialize($meta['meta_value']));
                 }
                 if (!empty($metadata)) {
                     $response[$key] = $metadata;
                 } else {
                     $response[$key] = false;
                 }
                 break;
             case 'meta':
                 $response[$key] = (object) array('links' => (object) array('self' => (string) $this->get_post_link($this->api->get_blog_id_for_output(), $post->ID), 'help' => (string) $this->get_post_link($this->api->get_blog_id_for_output(), $post->ID, 'help'), 'site' => (string) $this->get_site_link($this->api->get_blog_id_for_output()), 'replies' => (string) $this->get_post_link($this->api->get_blog_id_for_output(), $post->ID, 'replies/'), 'likes' => (string) $this->get_post_link($this->api->get_blog_id_for_output(), $post->ID, 'likes/')));
                 // add autosave link if a more recent autosave exists
                 if ('edit' === $context) {
                     $autosave = wp_get_post_autosave($post_id);
                     if ($autosave && $autosave->post_modified > $post->post_modified) {
                         $response[$key]->links->autosave = (string) $this->get_post_link($this->api->get_blog_id_for_output(), $post->ID) . '/autosave';
                     }
                 }
                 break;
             case 'capabilities':
                 $response[$key] = $capabilities;
                 break;
             case 'other_URLs':
                 $other_urls = array();
                 if ('publish' !== $post->post_status) {
                     $other_urls = $this->get_post_permalink_suggestions($post->ID, $post->post_title);
                 }
                 $response[$key] = (object) $other_urls;
                 break;
         }
     }
     // WPCOM_JSON_API_Post_Endpoint::find_featured_worthy_media( $post );
     // $response['featured_media'] = self::find_featured_media( $response );
     unset($GLOBALS['post']);
     return $response;
 }

/**
 * 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);
}

/**
 * Display list of a post's revisions.
 *
 * Can output either a UL with edit links or a TABLE with diff interface, and
 * restore action links.
 *
 * Second argument controls parameters:
 *   (bool)   parent : include the parent (the "Current Revision") in the list.
 *   (string) format : 'list' or 'form-table'. 'list' outputs UL, 'form-table'
 *                     outputs TABLE with UI.
 *   (int)    right  : what revision is currently being viewed - used in
 *                     form-table format.
 *   (int)    left   : what revision is currently being diffed against right -
 *                     used in form-table format.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @uses wp_get_post_revisions()
 * @uses wp_post_revision_title()
 * @uses get_edit_post_link()
 * @uses get_the_author_meta()
 *
 * @todo split into two functions (list, form-table) ?
 *
 * @param int|object $post_id Post ID or post object.
 * @param string|array $args See description {@link wp_parse_args()}.
 * @return null
 */
function wp_list_post_revisions($post_id = 0, $args = null)
{
    if (!($post = get_post($post_id))) {
        return;
    }
    $defaults = array('parent' => false, 'right' => false, 'left' => false, 'format' => 'list', 'type' => 'all');
    extract(wp_parse_args($args, $defaults), EXTR_SKIP);
    switch ($type) {
        case 'autosave':
            if (!($autosave = wp_get_post_autosave($post->ID))) {
                return;
            }
            $revisions = array($autosave);
            break;
        case 'revision':
            // just revisions - remove autosave later
        // just revisions - remove autosave later
        case 'all':
        default:
            if (!($revisions = wp_get_post_revisions($post->ID))) {
                return;
            }
            break;
    }
    /* translators: post revision: 1: when, 2: author name */
    $titlef = _x('%1$s by %2$s', 'post revision');
    if ($parent) {
        array_unshift($revisions, $post);
    }
    $rows = $right_checked = '';
    $class = false;
    $can_edit_post = current_user_can('edit_post', $post->ID);
    foreach ($revisions as $revision) {
        if (!current_user_can('read_post', $revision->ID)) {
            continue;
        }
        if ('revision' === $type && wp_is_post_autosave($revision)) {
            continue;
        }
        $date = wp_post_revision_title($revision);
        $name = get_the_author_meta('display_name', $revision->post_author);
        if ('form-table' == $format) {
            if ($left) {
                $left_checked = $left == $revision->ID ? ' checked="checked"' : '';
            } else {
                $left_checked = $right_checked ? ' checked="checked"' : '';
            }
            // [sic] (the next one)
            $right_checked = $right == $revision->ID ? ' checked="checked"' : '';
            $class = $class ? '' : " class='alternate'";
            if ($post->ID != $revision->ID && $can_edit_post) {
                $actions = '<a href="' . wp_nonce_url(add_query_arg(array('revision' => $revision->ID, 'action' => 'restore')), "restore-post_{$post->ID}|{$revision->ID}") . '">' . __('Restore') . '</a>';
            } else {
                $actions = '';
            }
            $rows .= "<tr{$class}>\n";
            $rows .= "\t<th style='white-space: nowrap' scope='row'><input type='radio' name='left' value='{$revision->ID}'{$left_checked} /></th>\n";
            $rows .= "\t<th style='white-space: nowrap' scope='row'><input type='radio' name='right' value='{$revision->ID}'{$right_checked} /></th>\n";
            $rows .= "\t<td>{$date}</td>\n";
            $rows .= "\t<td>{$name}</td>\n";
            $rows .= "\t<td class='action-links'>{$actions}</td>\n";
            $rows .= "</tr>\n";
        } else {
            $title = sprintf($titlef, $date, $name);
            $rows .= "\t<li>{$title}</li>\n";
        }
    }
    if ('form-table' == $format) {
        ?>

//.........这里部分代码省略.........

/**
 * Sets up the post object for preview based on the post autosave.
 *
 * @since 2.7.0
 * @access private
 *
 * @param WP_Post $post
 * @return WP_Post|false
 */
function _set_preview($post)
{
    if (!is_object($post)) {
        return $post;
    }
    $preview = wp_get_post_autosave($post->ID);
    if (!is_object($preview)) {
        return $post;
    }
    $preview = sanitize_post($preview);
    $post->post_content = $preview->post_content;
    $post->post_title = $preview->post_title;
    $post->post_excerpt = $preview->post_excerpt;
    add_filter('get_the_terms', '_wp_preview_terms_filter', 10, 3);
    return $post;
}