I'm working on an internal knowledgebase and I want to show the post history on the front end (with something like author, date and difference).

I first landed on wp_get_post_revision() (https://developer.wordpress.org/reference/functions/wp_get_post_revision/) and after more searching I found wp_list_post_revisions() (https://developer.wordpress.org/reference/functions/wp_list_post_revisions/) which looks closer to what I want.

However, while messing with this I'm running into errors while updating posts (Updating failed. The response is not a valid JSON response.) and I don't see anything on the front end when I return the shortcode. I was hoping there was a plugin for this but since I cannot find one I'm creating a quick one. What am I doing wrong and what's the best way to accomplish this?

Here is what I've tried:

function history_shortcode() {
    //global $wpdb;
    //$revisions = $wpdb->get_results("select * from {$wpdb->posts} where post_parent={$post_id} and post_type='revision'");

    $revisions = wp_list_post_revisions(get_the_ID());
    return $revisions;

add_shortcode( 'history', 'history_shortcode' );

1 Answer 1


Your shortcode calls wp_list_post_revisions() which echo the output (revision list), hence you get the "updating error".

To fix the issue, you can use output buffering like so:

wp_list_post_revisions( get_the_ID() );
$revisions = ob_get_clean();

Or you could use wp_get_post_revisions() and build the HTML list manually. Here's an example based on the wp_list_post_revisions():

$output = '';

if ( ! $revisions = wp_get_post_revisions( get_the_ID() ) ) {
    return $output;

$rows = '';
foreach ( $revisions as $revision ) {
    if ( ! current_user_can( 'read_post', $revision->ID ) ) {

    $rows .= "\t<li>" . wp_post_revision_title_expanded( $revision ) . "</li>\n";

$output .= "<ul class='post-revisions hide-if-no-js'>\n";
$output .= $rows;
$output .= '</ul>';

// At the end of your shortcode function, make sure to..
return $output;
  • 1
    This works perfectly, thank you!
    – Derek
    Commented Jan 29, 2021 at 14:56

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.