[Catalog] Require xx_XX locale format when syncing to Gally Fixes #32

Author: PierreGauthier

README.md

@@ -110,6 +110,8 @@
           > The `nodejs` container automatically runs `yarn install && yarn build` and mounts the project into `/srv/sylius`.
     - Run `php bin/console doctrine:migrations:migrate` to update the database schema
     - Open Sylius Admin, head to Configuration > Gally and configure the Gally endpoint (URL, credentials), after that enable Gally on your channel (Configuration > Channel > Edit)
+      > Every locale enabled on a Gally-active channel must use the full `xx_XX` format (e.g. `en_US`), not a bare
+      > language code (e.g. `en`). Configure this in Sylius under Configuration > Locales.
 - Run this commands from your Sylius instance. This commands must be runned only once to synchronize the structure.
     ```shell
         bin/console gally:structure:sync   # Sync catalog et source field data with gally

src/Indexer/Provider/CatalogProvider.php

@@ -63,11 +63,16 @@ public function buildLocalizedCatalog(ChannelInterface $channel, LocaleInterface
             );
         }
 
+        $localeCode = str_replace('-', '_', (string) $locale->getCode());
+        if (1 !== preg_match('/^[a-z]{2}_[A-Z]{2}$/', $localeCode)) {
+            throw new \InvalidArgumentException(sprintf('Gally requires locales in the "xx_XX" format (e.g. "en_US"), got "%s" for channel "%s". Configure a full locale in Sylius (Configuration > Locales).', $localeCode, (string) $channel->getCode()));
+        }
+
         return new LocalizedCatalog(
             $this->catalogCache[$channel->getCode()],
             $channel->getCode() . '_' . $locale->getCode(),
             (string) $locale->getName(),
-            str_replace('-', '_', (string) $locale->getCode()),
+            $localeCode,
             (string) $channel->getBaseCurrency()?->getCode(),
         );
     }