D8/D9 - Configurable tag overriding (#30)

* adding placeholder for readme update

* adding override setting

* override fixing

* test

* update function

* install config

* readme

* better readme

* Update src/EventSubscriber/CacheableResponseSubscriber.php

Co-authored-by: Clay Freeman <[email protected]>

* Update src/EventSubscriber/CacheableResponseSubscriber.php

Co-authored-by: Clay Freeman <[email protected]>

* Update src/EventSubscriber/CacheableResponseSubscriber.php

Co-authored-by: Clay Freeman <[email protected]>

* Update README.md

Co-authored-by: Clay Freeman <[email protected]>

* Update src/EventSubscriber/CacheableResponseSubscriber.php

Co-authored-by: Clay Freeman <[email protected]>

* Update src/EventSubscriber/CacheableResponseSubscriber.php

Co-authored-by: Clay Freeman <[email protected]>

* Update src/EventSubscriber/CacheableResponseSubscriber.php

Co-authored-by: Clay Freeman <[email protected]>

* codesniff fix

Co-authored-by: Clay Freeman <[email protected]>

README.md

@@ -22,6 +22,16 @@ A direct way of inspecting headers is with `curl -I`. This command will make a r
 
 `curl -IH "Pantheon-Debug:1" https://dev-cache-tags-demo.pantheonsite.io/ | grep -i Surrogate-Key-Raw`
 
+## Changing Listing Tags
+
+Prior to the 1.2 release, this module would change the cache tags used on default listings.
+This changing of was done to make cache hits more likely but resulted in [confusing cache clearing behavior](https://www.drupal.org/project/pantheon_advanced_page_cache/issues/2944229).
+Sites that installed this module prior to 1.2 should uninstall and reinstall or run this command to update their settings.
+
+```
+terminus drush [MACHINE-NAME-OF-SITE].[ENV-NAME] -- config:set pantheon_advanced_page_cache.settings --input-format=yaml   "override_list_tags" "false"
+```
+
 ## Limit on header size
 
 Pantheon's nginx configuration limits total header size to 32k.

config/install/pantheon_advanced_page_cache.settings.yml

@@ -0,0 +1 @@
+override_list_tags: false

pantheon_advanced_page_cache.install

@@ -0,0 +1,13 @@
+<?php
+
+/**
+ * @file
+ * Update functions for the Pantheon Advanced Page Cache module.
+ */
+
+/**
+ * Set override_list_tags to TRUE for backwards compatibility. We recommend manually changing to FALSE for more consistent clearing. See README
+ */
+function pantheon_advanced_page_cache_update_8001() {
+  \Drupal::configFactory()->getEditable('pantheon_advanced_page_cache.settings')->set('override_list_tags', TRUE)->save();
+}

pantheon_advanced_page_cache.services.yml

@@ -8,6 +8,6 @@ services:
       - { name: cache_tags_invalidator }
   pantheon_advanced_page_cache.cacheable_response_subscriber:
     class: Drupal\pantheon_advanced_page_cache\EventSubscriber\CacheableResponseSubscriber
-    arguments: ['@logger.channel.pantheon_advanced_page_cache']
+    arguments: ['@logger.channel.pantheon_advanced_page_cache', '@config.factory']
     tags:
       - { name: event_subscriber }

src/EventSubscriber/CacheableResponseSubscriber.php

@@ -8,6 +8,7 @@
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Psr\Log\LoggerInterface;
 use Drupal\Core\Logger\RfcLogLevel;
+use Drupal\Core\Config\ConfigFactoryInterface;
 
 /**
  * Adds Surrogate-Key header to cacheable master responses.
@@ -21,14 +22,44 @@ class CacheableResponseSubscriber implements EventSubscriberInterface {
    */
   protected $logger;
 
+  /**
+   * Configuration Factory.
+   *
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
+   */
+  protected $configFactory;
+
   /**
    * Constructs a new DefaultExceptionHtmlSubscriber.
    *
    * @param \Psr\Log\LoggerInterface $logger
    *   The logger service.
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
+   *   Configuration for this module.
    */
-  public function __construct(LoggerInterface $logger) {
+  public function __construct(LoggerInterface $logger, ConfigFactoryInterface $config_factory = NULL) {
+    if (!$config_factory instanceof ConfigFactoryInterface) {
+      @trigger_error('Not passing the config factory service as the second parameter to ' . __METHOD__ . ' is deprecated in pantheon_advanced_page_cache:8.x-1.2 and will throw a type error in pantheon_advanced_page_cache:8.x-2.0. Pass an instance of \\Drupal\\Core\\Config\\ConfigFactoryInterface. See https://www.drupal.org/node/2944229', E_USER_DEPRECATED);
+      $config_factory = \Drupal::service('config.factory');
+    }
     $this->logger = $logger;
+    $this->configFactory = $config_factory;
+  }
+
+  /**
+   * Returns whether entity_list tags should be overridden.
+   *
+   * Overriding these tags was the initial behavior of the 1.0 version of this
+   * module. That is no longer recommended.
+   */
+  public function getOverrideListTagsSetting() {
+    $config = $this->configFactory->get('pantheon_advanced_page_cache.settings');
+    // Only return FALSE if this config value is really set to false.
+    // A null value should return TRUE for backwards compatibility.
+    if ($config->get('override_list_tags') === FALSE) {
+      return FALSE;
+    }
+    return TRUE;
   }
 
   /**
@@ -49,8 +80,10 @@ public function onRespond(FilterResponseEvent $event) {
 
       // Rename all _list cache tags to _emit_list to avoid clearing list cache
       // tags by default.
-      foreach ($tags as $key => $tag) {
-        $tags[$key] = str_replace('_list', '_emit_list', $tag);
+      if ($this->getOverrideListTagsSetting()) {
+        foreach ($tags as $key => $tag) {
+          $tags[$key] = str_replace('_list', '_emit_list', $tag);
+        }
       }
 
       $tags_string = implode(' ', $tags);

tests/behat/features/override_list_tag.feature

@@ -0,0 +1,21 @@
+Feature: Listing tags
+In order to control caching of lists
+As an administrator
+I want to toggle the setting for overriding cache tags
+
+  @api
+  Scenario: Core behavior
+    Given there are some "article" nodes
+    And "/" is caching
+    When a generate a "article" node
+    Then "/" has been purged
+    And "/" is caching
+
+  @api @current
+  Scenario: Old override
+    Given there are some "article" nodes
+    When I run drush "config:set pantheon_advanced_page_cache.settings --input-format=yaml   override_list_tags true"
+    And "/" is caching
+    When a generate a "article" node
+    And "/" has not been purged
+