get_canonical snippet

get_canonical.php

<?php
//error_reporting(E_ALL);
//ini_set('display_errors', 1);


if (!function_exists('self_canonical')) 
{
function self_canonical($currentContext)
  {
    global $modx;

    $ctx        = $modx->getContext($currentContext);
    $host       = $ctx->getOption('http_host');
    $uri        = parse_url( $_SERVER['REQUEST_URI'], PHP_URL_PATH );
    $path       = ($uri == 'index/') ? '' : $uri;
    $scheme     = (count(explode('.', $host)) > 2) ? 'http://' : 'http://www.';
    $linkedURL  = $scheme . $host . $path;

    $linkTag = "<link rel=\"canonical\" href=\"$linkedURL\"/>";
    $modx->regClientStartupHTMLBlock($linkTag);
  }
}


if(!function_exists('canonical'))
{
function canonical($currentContext)
  {
    //echo "Canonical " . $currentContext;
    return;
  }
}

if(!function_exists('canonicalSpecial'))
{
function canonicalSpecial($currentContext)
  {
    global $modx;
    
    $noCanonicalTemplates = [21,40];  // id's of templates where not to set canonical from this snippet (special rules for canonical) :: ARTICLES, PARENT_ABOUT
    $page = $modx->getObject('modResource', $modx->resource->get('id'));
    $template = $page->get('template');

    if (in_array($template, $noCanonicalTemplates)) 
    {
        $uri                = parse_url( $_SERVER['REQUEST_URI'], PHP_URL_PATH );
        $uri_segments       = explode('/', $uri);
        $last_uri_segment   = end($uri_segments);
        
        if (is_numeric($last_uri_segment)) {  // check if URI is like 
            //self_canonical($currentContext);
            return;
        }
    }
    else {
        self_canonical($currentContext);
    }
  }
}



$currentContext = $modx->context->get('key');

switch ($currentContext) {
    case "ukltd":
        //canonicalSpecial($currentContext);
        //break;
    case "ukltd-ru":
    case "bg":
    case "cl":
    case "nl":
    case "hr":
    case "cz":
    case "de":
    case "ee":
    case "es":
    case "fr":
    case "hu":
    case "lt":
    case "lv":
    case "pl":
    case "ro":
    case "sl":
        self_canonical($currentContext);
        break;
    case "au":
    case "lv-ru":
    case "ee-ru":
    case "md-ru":
        canonical($currentContext);
        break;
    default:
        break;

}