Better handling of special system and quant pages

[kepol]

The handling of special pages in 3 pages doesn't always take into consideration 1) if the site config has been set and 2) if the page is available. Need to update the logic to check these before adding to routes/etc.

Old description:

Right now, /_quant403 and /_quant404 are added when seeding even if the site configuration hasn't been created for the 403 and 404 pages. We should only add these into the $specialPages if they have been added to the site configuration.

    // Special case pages (403/404/Home)
    $specialPages = [
      '/' => $site_config->get('page.front'),
      '/_quant404' => $site_config->get('page.404'),
      '/_quant403' => $site_config->get('page.403'),
    ];

[kepol]

Actually, there is code in 3 places that deals with the home page and 404/403 pages so it's confusing. I was trying to test changing these but not sure this is the best thing. It would be good to understand why similar logic is in multiple places.

+++ b/quant.module
@@ -336,8 +336,10 @@ function quant_special_pages() {
     '/_quant403',
   ];
 
-  foreach ($system_pages as $route) {
-    $item = new RouteItem(['route' => $route]);
-    $item->send();
+  foreach ($system_pages as $page) {
+    if (\Drupal::service('path.validator')->getUrlIfValid($page)) {
+      $item = new RouteItem(['route' => $page]);
+      $item->send();
+    }

+++ b/src/Seed.php
@@ -206,12 +206,18 @@ class Seed {
       }
     }
 
-    // Special case pages (403/404/Home)
-    $specialPages = [
-      '/' => $site_config->get('page.front'),
-      '/_quant404' => $site_config->get('page.404'),
-      '/_quant403' => $site_config->get('page.403'),
+    // Special case pages (Home/404/403).
+    $specialPages = [];
+    $pageConfig = [
+      '/' => 'page.front',
+      '/_quant404' => 'page.404',
+      '/_quant403' => 'page.403',
     ];
+    foreach ($pageConfig as $page => $config) {
+      if (!empty($site_config->get($config))) {
+        $specialPages[$page] = $site_config->get($config);
+      }
+    }

+++ b/src/EventSubscriber/CollectionSubscriber.php
@@ -207,7 +207,9 @@ class CollectionSubscriber implements EventSubscriberInterface {
     $quant_pages = ['/', '/_quant404', '/_quant403'];
 
     foreach ($quant_pages as $page) {
-      $event->queueItem(['route' => $page]);
+      if (\Drupal::service('path.validator')->getUrlIfValid($page)) {
+        $event->queueItem(['route' => $page]);
+      }
     }

[kepol]

Tested those changes and they seem to fix the errors... just not sure that's the best approach.

[kepol]

Ported to d.o issue so closing:

https://www.drupal.org/project/quantcdn/issues/3412392