Display revision if post status is pending

I’m trying to display the latest post revision if the page is “pending”, by default the page displays a 404 if it is pending. But I want it to show the latest revision until the page is updated.

The code below doesn’t seem to display anything but the title, I have used a hook to the wp_insert_post_data function which changes the status of the post to “pending” if the users role isn’t admin.

The post is set to pending in the database, but I cannot get the below code to show the latest revision?

I also don’t know how to prevent it from redirecting to a 404 page? If I am logged in it will show the post otherwise a 404 page.

    <?php while (have_posts()) : the_post(); ?>    
            <h1><?php the_title(); ?></h1>                          
        <?php 
        echo get_post_status(); //echo's pending
        if(get_post_status() == 'pending') {
            $query = new WP_Query(array('post_type' => 'revision', 'post_parent' => '7', 'posts_per_page' => 1)); // 7 is the current page ID
            if ($query->have_posts()) {                 
                while ($query->have_posts()) {                      
                    $query->the_post();                     
                    the_content();
                    echo $post->ID;
                }
            }
            wp_reset_postdata();
        } else {
            the_content(); 
        }               
        ?>           
    <?php endwhile; ?>
<?php endif; ?>

Any advice? Is there an easier way to show the revision if the page is pending?

Thanks !

Edit:

Okay I seem to have it working using the code below:

if(get_post_status() == 'pending') {
   $query = 'SELECT ID FROM `wp_posts` WHERE `post_parent` = '.$post->ID.' AND `post_type` = "revision" AND `post_status` = "pending" AND `post_title` <> "Auto Draft" AND TRIM(`post_content`) <> "" AND `post_name` NOT LIKE "%autosave%" ORDER BY `post_modified` DESC LIMIT 1';
   $revision_id = $wpdb->get_var($query);
   $revision = wp_get_post_revision($revision_id);
   $content = $revision->post_content;              
   $content = apply_filters('the_content', $content);
   $content = str_replace(']]>', ']]>', $content);
   echo $content;
   wp_reset_postdata();
} else {
   the_content(); 
}

So now the question is – How can I prevent a page which is set as pending to redirecting to the 404 page?

It took me a while but I got it! This works as follows:

1. Since you have no reference to the post other than the URI, we segment out the URI to check for a page with that page_name
2. If there is a page, we get the latest revision child
3. Hack the query to force our revision slug to source the page

This works swell because it gives the appearance of a working permalink. It acts as a pseudo permalink.

add_action( 'wp', 'override_404' );
function override_404($query) {

    if(is_404):

        $uri = trim($_SERVER['REQUEST_URI'], "https://wordpress.stackexchange.com/");
        $segments = explode("https://wordpress.stackexchange.com/", $uri);
        $slug_index = count($segments);

        $page_slug = $segments[$slug_index - 1];
        $page = get_page_by_path($page_slug, OBJECT, 'page');

        $revision_args = array('post_parent' => $page->ID, 'post_type' => 'revision', 'post_status' => 'inherit', 'numberposts' => 1);
        $revision = array_shift(get_children($revision_args));

        if($revision):
            $query->query_vars['pagename'] = $revision->page_name;          
            $query->query_string = "pagename={$revision->page_name}";
            $query->request = $revision->page_name;
            $query->matched_rule = "({$revision->page_name})(/[0-9]+)?/?$";
            $query->matched_query = "pagename={$revision->page_name}&page=";
            $query->did_permalink = 1;
        endif;

    endif;

    return $query;
}

The only caveat is sometimes the slug does not save until you publish the page. In order for this to work correctly, the slug must be in the database. Cheers!