gmseofields.php

<?php
/**
 * Adds canonical, hreflang and prev next tags to the header
 *
 * @package   gmseofields
 * @author    Jae (me@jae.fi)
 * @copyright Copyright (c) Jae
 * @license   http://opensource.org/licenses/afl-3.0.php  Academic Free License (AFL 3.0)
 */
if (!defined('_PS_VERSION_')) {
    exit;
}

class GmSeoFields extends Module
{
    private $nobotsControllers = array(
        '404',
        'address',
        'addresses',
        'attachment',
        'authentication',
        'cart',
        'discount',
        'footer',
        'get-file',
        'guest-tracking',
        'header',
        'history',
        'identity',
        'images.inc',
        'init',
        'my-account',
        'order',
        'order-opc',
        'order-slip',
        'order-detail',
        'order-follow',
        'order-return',
        'order-confirmation',
        'pagination',
        'password',
        'pdf-invoice',
        'pdf-order-return',
        'pdf-order-slip',
        'product-sort',
        'search',
        'statistics',
    );

    public function __construct()
    {
        $this->name = 'gmseofields';
        $this->tab = 'front_office_features';
        $this->version = '1.0.1';
        $this->author = 'Jae';
        $this->bootstrap = true;
        $this->need_instance = 0;

        parent::__construct();

        $this->displayName = $this->l('SEO Fields');
        $this->description = $this->l('Adds canonical, hreflang, prev, next and noindex tags to the header');
        $this->ps_versions_compliancy = array('min' => '1.6', 'max' => _PS_VERSION_);
    }

    public function install()
    {
        return parent::install() && $this->registerHook('displayHeader');
    }

    public function getContent()
    {
        return $this->context->smarty->fetch($this->local_path . 'views/templates/admin/gms.tpl');
    }

    public function hookDisplayHeader()
    {
        if ($this->handleNobots()) {
            // no need to add anything else as robots should ignore this page
            return;
        }

        $this->php_self = Tools::getValue('controller');
        return $this->getSeoFields();
    }

    private function handleNobots()
    {
        if (in_array($this->context->controller->php_self, $this->nobotsControllers, true) || Tools::getValue('selected_filters')
        ) {
            $this->context->smarty->assign('nobots', true);
            return true;
        }
        return false;
    }

    public function getSeoFields()
    {
        $content = '';
        $languages = Language::getLanguages();
        $defaultLang = Configuration::get('PS_LANG_DEFAULT');
        switch ($this->php_self) {
            case 'product': // product page
                $idProduct = (int) Tools::getValue('id_product');
                $canonical = $this->context->link->getProductLink($idProduct);
                $hreflang = $this->getHrefLang('product', $idProduct, $languages, $defaultLang);
                break;

            case 'manufacturer':
                $idManufacturer = (int) Tools::getValue('id_manufacturer');
                $content .= $this->getRelPrevNext('manufacturer', $idManufacturer);
                $hreflang = $this->getHrefLang('manufacturer', $idManufacturer, $languages, $defaultLang);

                if (!$idManufacturer) {
                    $canonical = $this->context->link->getPageLink('manufacturer');
                } else {
                    $canonical = $this->context->link->getManufacturerLink($idManufacturer);
                }
                break;

            case 'supplier':
                $idSupplier = (int) Tools::getValue('id_supplier');
                $content .= $this->getRelPrevNext('supplier', $idSupplier);
                $hreflang = $this->getHrefLang('supplier', $idSupplier, $languages, $defaultLang);

                if (!Tools::getValue('id_supplier')) {
                    $canonical = $this->context->link->getPageLink('supplier');
                } else {
                    $canonical = $this->context->link->getSupplierLink((int) Tools::getValue('id_supplier'));
                }
                break;

            case 'cms':
                $idCms = Tools::getValue('id_cms');
                $idCmsCategory = Tools::getValue('id_cms_category');

                $shops = array();
                $array_shops = Db::getInstance()->executeS('SELECT virtual_uri FROM ' . _DB_PREFIX_ . 'shop_url');

                $refNumber = count(Db::getInstance()->executeS('SELECT * FROM ' . _DB_PREFIX_ . 'cms_shop WHERE id_cms = \'' . $idCms . '\''));

                foreach ($array_shops as $pushShops) {
                    $shops[] = $pushShops['virtual_uri'];
                }

                $firstShop = Db::getInstance()->executeS('SELECT * FROM ' . _DB_PREFIX_ . 'shop_url INNER JOIN ' . _DB_PREFIX_ . 'cms_shop ON ' . _DB_PREFIX_ . 'cms_shop.id_cms = \'' . $idCms . '\' AND ' . _DB_PREFIX_ . 'shop_url.id_shop = ' . _DB_PREFIX_ . 'cms_shop.id_shop');

                if ($idCms) {
                    if ($refNumber > 1) {
                        $canonical = str_replace($shops, $firstShop[0]['virtual_uri'], $this->context->link->getCMSLink((int) $idCms));
                        $hreflang = str_replace($shops, $firstShop[0]['virtual_uri'], $this->getHrefLang('cms', (int) $idCms, $languages, $defaultLang));
                    } else {
                        $canonical = $this->context->link->getCMSLink((int) $idCms);
                        $hreflang = $this->getHrefLang('cms', (int) $idCms, $languages, $defaultLang);
                    }
                } else {
                    if ($refNumber > 1) {
                        $canonical = $this->context->link->getCMSCategoryLink((int) $idCmsCategory);
                        $hreflang = $this->getHrefLang('cms_category', (int) $idCmsCategory, $languages, $defaultLang);
                    } else {
                        $canonical = str_replace($shops, "", $this->context->link->getCMSCategoryLink((int) $idCmsCategory));
                        $hreflang = str_replace($shops, "", $this->getHrefLang('cms_category', (int) $idCmsCategory, $languages, $defaultLang));
                    }
                }
                break;

            case 'details':
                if(Configuration::get('smartblogurlpattern') != 1) {
                    $postId = Tools::getValue('id_post');
                } else {
                    $SmartBlog = new smartblog();
                    $slug = Tools::getValue('slug');
                    $postId = $SmartBlog->slug2id($slug);
                }

                $listDescs = Db::getInstance()->executeS('SELECT * FROM ' . _DB_PREFIX_ . 'smart_blog_post_lang WHERE id_smart_blog_post = \'' . $postId . '\'');

                foreach (Language::getLanguages(true, $this->context->shop->id) as $siteLangs) {
                    $langs[] = '/' . $siteLangs['iso_code'] . '/';

                    if ($siteLangs['id_lang'] == Configuration::get('PS_LANG_DEFAULT')) {
                        $defaultLang = '/' . $siteLangs['iso_code'] . '/';
                        $defaultLangIso = $siteLangs['iso_code'];
                    }
                }

                foreach ($listDescs as $postData) {
                    if ($postData['id_lang'] == Context::getContext()->language->id) {
                        if(Configuration::get('smartblogurlpattern') != 1) {
                            $postSlug = $postId . '_' . $postData['link_rewrite'];
                        } else {
                            $postSlug = Tools::getValue('slug');
                        }
                    }
                }

                $canonical = str_replace('.html', '', smartblog::GetSmartBlogLink('smartblog')) . '/' . $postSlug . '.html';
                $langs = array_unique($langs);

                foreach ($listDescs as $blogDesc) {
                    foreach (Language::getLanguages(true, $this->context->shop->id) as $siteLangs) {
                        if ($blogDesc['id_lang'] == $siteLangs['id_lang']) {
                            $linkBuild = str_replace($langs, '/' . $siteLangs['iso_code'] . '/', '<link rel="alternate" href="' . $canonical . '" hreflang="' . $siteLangs['iso_code'] . '">');

                            if(Configuration::get('smartblogurlpattern') != 1) {
                                $linkBuild = str_replace($postSlug, $postId . '_' . $blogDesc['link_rewrite'], $linkBuild);
                            } else {
                                $linkBuild = str_replace($postSlug, $blogDesc['link_rewrite'], $linkBuild);
                            }

                            if ($siteLangs['iso_code'] == $defaultLangIso) {
                                if(Configuration::get('smartblogurlpattern') != 1) {
                                    $rew = str_replace($postSlug, $postId . '_' . $blogDesc['link_rewrite'], $canonical);
                                } else {
                                    $rew = str_replace($postSlug, $blogDesc['link_rewrite'], $canonical);
                                }
                            }

                            $hreflang[] = $linkBuild;
                        }
                    }
                }

                $hreflang[] = str_replace($langs, $defaultLang, '<link rel="alternate" href="' . $rew . '" hreflang="x-default">');
                $hreflang = array_unique($hreflang);
                break;

            case 'category':
                $canonical = 'https://' . _PS_BASE_URL_ . $_SERVER['REQUEST_URI'];

                foreach(Language::getLanguages(true, $this->context->shop->id) as $siteLangs) {
                    $langs[] = '/' . $siteLangs['iso_code'] . '/';

                    if ($siteLangs['id_lang'] == Configuration::get('PS_LANG_DEFAULT')) {
                        $defaultLang = '/' . $siteLangs['iso_code'];
                        $defaultLangIso = $siteLangs['iso_code'];
                    }
                }

                $langs = array_unique($langs);

                foreach(Language::getLanguages(true, $this->context->shop->id) as $siteLangs) {
                    $linkBuild = str_replace($langs, '/' . $siteLangs['iso_code'] . '/', '<link rel="alternate" href="' . $canonical . '" hreflang="' . $siteLangs['iso_code'] . '">');

                    if ($siteLangs['iso_code'] == $defaultLangIso) {
                        $rew = str_replace($postSlug, $blogDesc['link_rewrite'], $canonical);
                    }

                    $hreflang[] = $linkBuild;
                }

                $hreflang[] = str_replace($langs, $defaultLang, '<link rel="alternate" href="' . $rew . '" hreflang="x-default">');
                $hreflang = array_unique($hreflang);
                break;

            default:
                $canonical = 'https://' . _PS_BASE_URL_ . $_SERVER['REQUEST_URI'];
                $hreflang = $this->getHrefLang($this->php_self, 0, $languages, $defaultLang);
                break;
        }

        // build new content
        $content .= '<link rel="canonical" href="' . $canonical . '">' . "\n";
        if (is_array($hreflang) && !empty($hreflang)) {
            foreach ($hreflang as $lang) {
                $content .= "$lang\n";
            }
        }

        return $content;
    }

    public function getHrefLang($entity, $idItem, $languages, $idLangDefault)
    {
        $links = array();
        foreach ($languages as $lang) {
            switch ($entity) {
                case 'product':
                    $lnk = $this->context->link->getProductLink((int) $idItem, null, null, null, $lang['id_lang']);
                    break;

                case 'category':
                    $lnk = $this->context->link->getCategoryLink((int) $idItem, null, $lang['id_lang']);
                    break;

                case 'manufacturer':
                    if (!$idItem) {
                        $lnk = $this->context->link->getPageLink('manufacturer', null, $lang['id_lang']);
                    } else {
                        $lnk = $this->context->link->getManufacturerLink((int) $idItem, null, $lang['id_lang']);
                    }
                    break;

                case 'supplier':
                    if (!$idItem) {
                        $lnk = $this->context->link->getPageLink('supplier', null, $lang['id_lang']);
                    } else {
                        $lnk = $this->context->link->getSupplierLink((int) $idItem, null, $lang['id_lang']);
                    }
                    break;

                case 'cms':
                    $lnk = $this->context->link->getCMSLink((int) $idItem, null, null, $lang['id_lang']);
                    break;

                case 'cms_category':
                    $lnk = $this->context->link->getCMSCategoryLink((int) $idItem, null, $lang['id_lang']);
                    break;

                default:
                    $lnk = $this->context->link->getPageLink($entity, null, $lang['id_lang']);
                    break;
            }

            $links[] = '<link rel="alternate" href="' . $lnk . '" hreflang="' . $lang['language_code'] . '">';
            if ($lang['id_lang'] == $idLangDefault) {
                $links[] = '<link rel="alternate" href="' . $lnk . '" hreflang="x-default">';
            }
        }

        return $links;
    }

    public function getRelPrevNext($entity, $idItem)
    {
        switch ($entity) {
            case 'category':
                $category = new Category((int) $idItem);
                $nbProducts = $category->getProducts(null, null, null, null, null, true);
                break;
            case 'manufacturer':
                $manufacturer = new Manufacturer($idItem);
                $nbProducts = $manufacturer->getProducts($manufacturer->id, null, null, null, null, null, true);
                break;
            case 'supplier':
                $supplier = new Supplier($idItem);
                $nbProducts = $supplier->getProducts($supplier->id, null, null, null, null, null, true);
                break;
            default:
                return '';
        }

        $p = Tools::getValue('p');
        $n = (int) Configuration::get('PS_PRODUCTS_PER_PAGE');

        $totalPages = ceil($nbProducts / $n);

        $linkprev = '';
        $linknext = '';
        $requestPage = $this->context->link->getPaginationLink($entity, $idItem, $n, false, 1, false);
        if (!$p) {
            $p = 1;
        }

        if ($p > 1) { // we need prev
            $linkprev = $this->context->link->goPage($requestPage, $p - 1);
        }

        if ($totalPages > 1 && $p + 1 <= $totalPages) {
            $linknext = $this->context->link->goPage($requestPage, $p + 1);
        }

        $return = '';

        if ($linkprev) {
            $return .= '<link rel="prev" href="' . $linkprev . '">';
        }
        if ($linknext) {
            $return .= '<link rel="next" href="' . $linknext . '">';
        }

        return $return;
    }
}