EPFL_last_page_changes.php

<?php
/*
Plugin Name: EPFL last page changes
Description: Gives the name of the last user who modified a given page.
Version: 0.0.3
Author: Jérôme Cosandey
Author URI: https://github.com/saphirevert
*/

function getLastChange( $data ){
    global $wpdb;
    $url = $data->get_param( 'url' );
    $postId = url_to_postid($url);
    if ($postId === 0 && trailingslashit(get_site_url()) !== trailingslashit($url)) {
      status_header(404, "This page does not exist");
      return http_response_code();
    } else {
      $sql = $wpdb->prepare( "SELECT wp_users.user_login AS username, post_modified AS last_modified FROM `wp_posts` 
                              LEFT JOIN wp_users ON wp_users.ID = wp_posts.post_author
                              WHERE post_parent=%d AND post_status!='publish' ORDER BY wp_posts.post_modified DESC LIMIT 1;", 
                              array(
                                $postId,
                              ));
      $results = $wpdb->get_results( $sql );
      return $results;
    }
}

function getLastRevisions( $data ){
    global $wpdb;
    $name = $data->get_param( 'name' );
    $name = $name ? $name : '';
    $limit = $data->get_param( 'limit' );
    $limit = $limit ? $limit : 5;
    $sql = $wpdb->prepare( "SELECT wp_posts.post_title, wp_users.user_login AS username, post_modified AS last_modified FROM `wp_posts` 
                            LEFT JOIN wp_users ON wp_users.ID = wp_posts.post_author 
                            WHERE wp_posts.post_title LIKE %s ORDER BY wp_posts.post_modified DESC LIMIT %d;", 
                            array(
                              '%' . $wpdb->esc_like($name) . '%',
                              $limit,
                            ));
    $results = $wpdb->get_results( $sql );
    return $results;
}

add_action( 'rest_api_init', function () {
  register_rest_route( 'epfl/v1', '/lastchange', array(
    'methods' => 'GET',
    'callback' => 'getLastChange',
  ));
  register_rest_route( 'epfl/v1', '/lastrevisions', array(
    'methods' => 'GET',
    'callback' => 'getLastRevisions',
  ));
});