[PLUGIN] SEO Strict URLs

<?php
// Strict URLs
// version 0.7.2
// Enforces the use of strict urls to prevent dup content.
// By Jeremy Luebke @ www.xuru.com
//   Override configuration added by Brian Stanback @ www.stanback.net

// On Install: Check the "OnWebPageInit" & "OnWebPagePrerender" boxs in the System Events tab.

// For overriding documents, create a new template variabe (TV) named seoOverride with the following options:
//    Input Type: DropDown List Menu
//    Input Option Values: Disabled==-1||Base Name==0||Append Extension==1||Folder==2
//    Default Value: -1

//  # Include the following in your .htaccess file
//  # Replace "example.com" &  "example\.com" with your domain info
//  RewriteCond %{HTTP_HOST} .
//  RewriteCond %{HTTP_HOST} !^www\.example\.com [NC]
//  RewriteRule (.*) http://www.example.com/$1 [R=301,L] 

// Config //
$editMenuLinks = 1; // Set to 1 to manipulate menu links. Set to 0 to leave them alone
$makeFolder = 0; // Set to 1 to enforce folders to display as /dir/ and not /dir.html

$override = 1; // Enable manual overrides
$overrideTV = "seoOverride"; // Name of the template var that contains the override value
$editOverrideLinks = 1; // Set to 1 to manipulate links for overridden documents. Set to 0 to leave them alone
$editOverrideCase = ""; // Set to "" to replace links beginning with lower case href= only or "i" to replace all cases of href (slower)

// Start Main Code //

$e = &$modx->event;

if($e->name=='OnWebPageInit') 
{
   $myProtocol = $_SERVER['HTTPS'] == on ? "https" : "http";  // Replace with $myProtocol = $modx->config['server_protocol'] to force the configured protocol

   $s = $_SERVER['REQUEST_URI'];
   $parts = explode("?", $s);  

   $documentIdentifier = ($modx->documentIdentifier) ? $modx->documentIdentifier : $modx->config['error_page'];  // Set error page document ID if page is not found

   $results = $modx->db->select("isfolder, alias", $modx->getFullTableName('site_content'), "id = " . $documentIdentifier);
   $row = $modx->fetchRow($results);
   $isfolder = $row['isfolder'];
   $alias = $row['alias'];

   if ($override && $overrideOption = $modx->getTemplateVarOutput($overrideTV,$documentIdentifier))
   {
      switch ($overrideOption[$overrideTV])
      {
         case 0:
            $isoverride = 1;
            break;
         case 1:
            $isfolder = 0;
            break;
         case 2:
            $makeFolder = 1;
            $isfolder = 1;
      }
   }

   if ($isoverride)
   {
      $strictURL = preg_replace('/[^\/]+$/', $alias, $modx->makeUrl($documentIdentifier));
   }
   elseif($isfolder && $makeFolder)
   {
      $strictURL = preg_replace('/[^\/]+$/', $alias, $modx->makeUrl($documentIdentifier)) . "/";
   }
   else
   {
      $strictURL = $modx->makeUrl($documentIdentifier);
   }

   $myDomain = $myProtocol . "://" . $_SERVER['HTTP_HOST'];

   $newURL = $myDomain . $strictURL;
   $requestedURL = $myDomain . $parts[0];

   if($documentIdentifier == $modx->config['site_start'] && $requestedURL != $modx->config['site_url'])
   {
      // Force use of root redirect
      header("HTTP/1.1 301 Moved Permanently");
      $qstring = preg_replace("#(^|&)(q|id)=[^&]+#", '', $parts[1]);  // Strip conflicting id/q from query string
      if ($qstring) header('Location: ' . $modx->config['site_url'] . '?' . $qstring);
      else header('Location: ' . $modx->config['site_url']);
      exit;
   }
   elseif($parts[0] != $strictURL && $documentIdentifier != $modx->config['site_start'])
   {
      // Force specific page redirect
      header("HTTP/1.1 301 Moved Permanently");
      $qstring = preg_replace("#(^|&)(q|id)=[^&]+#", '', $parts[1]);  // Strip conflicting id/q from query string
      if ($qstring) header('Location: ' . $strictURL . '?' . $qstring);
      else header('Location: ' . $strictURL);
      exit;
   }
}
elseif($e->name=='OnWebPagePrerender')
{
   if ($editMenuLinks)
   {
      $o = &$modx->documentOutput; // get a reference of the output
      $base_str = basename($modx->makeUrl($modx->config['site_start']));
      $o = preg_replace("#/?$base_str#",$modx->config['base_url'],$o);
   }

   if ($override && $editOverrideLinks)
   {
      if (!$editMenuLinks) $o = &$modx->documentOutput; // get a reference of the output
      $myDomain = $_SERVER['HTTP_HOST'];

      $sql = "SELECT tvc.contentid as id, tvc.value as value FROM " . $modx->getFullTableName('site_tmplvars') . " tv ";
      $sql .= "INNER JOIN " . $modx->getFullTableName('site_tmplvar_templates') . " tvtpl ON tvtpl.tmplvarid = tv.id ";
      $sql .= "LEFT JOIN " . $modx->getFullTableName('site_tmplvar_contentvalues') . " tvc ON tvc.tmplvarid = tv.id ";
      $sql .= "LEFT JOIN " . $modx->getFullTableName('site_content') . " sc ON sc.id = tvc.contentid ";
      $sql .= "WHERE sc.published = 1 AND tvtpl.templateid = sc.template AND tv.name = '$overrideTV'";
      $results = $modx->dbQuery($sql);
      while ($row = $modx->fetchRow($results))
      {
         $overrideURL = basename($modx->makeUrl($row['id']));
         switch ($row['value'])
         {
            case 0:
               $o = preg_replace("#(href=\"/?|$myDomain/)$overrideURL#$editOverrideCase", "$1" . str_replace(strrchr($overrideURL, '.'), '', $overrideURL),$o);
               break;
            case 2:
               $o = preg_replace("#(href=\"/?|$myDomain/)$overrideURL#$editOverrideCase", "$1" . str_replace(strrchr($overrideURL, '.'), '/', $overrideURL),$o);
               break;
         }
      }
   }
}
else
{
    return;
}
?>