isAdmin: MODx snippet for displaying content if user is logged into mgr or has a specified IP address

isAdmin

<?php
// ver 1.1.20201105a
//
// Most recent: https://gist.github.com/jcamachott/6126869
//
// should always be called uncached
// Usage:
// [[!isAdmin:is=`1`:then=`Do this`:else=`Do that`? &check=`mgr` &disable=`0`]]
//
// $check - get (has GET var admin=1) or mgr (manager logged in) or ip (ip address set in ++admin_ip)
// 
// $disable - when 1, will always output `Do this`

// CHANGELOG:
//
// Nov 5, 2020: Using $_SERVER['HTTP_X_FORWARDED_FOR'] before $_SERVER['REMOTE_ADDR']
//
//
 
$continue = 0;

if ($disable==1) {
  $continue = 1;
}

if ($check=='get' && $_GET['admin']==1) {
  $continue = 1;
}
else
{
  if (($check=='ip'))
  {
    // only check if admin's IP is in system variable
    $ip = $modx->config['admin_ip'];
    
    if(!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
      $remote_ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
    } else {
      $remote_ip = $_SERVER['REMOTE_ADDR'];
    }
    
    if ($ip==$remote_ip)
    {
        $continue = 1;
    }
  }

  if ($check=='mgr')
  {
    if ($modx->user instanceof modUser) {
        if ($modx->user->hasSessionContext('mgr')) { 
          $continue = 1;
        }
    }
  }

}
 
return $continue;