refs #16618 [master-v5] specify additional modules via composer configuration

composer.local.0.finc.json

 {
+    "autoload": {
+        "classmap": ["devops/composer/modules.php"]
+    },
     "require": {
         "finc/rules-evaluator": "0.0.3",
         "sabre/vobject": "3.5.3",
         "symfony/filesystem": "^3.4"
     },
     "scripts": {
-        "post-install-cmd": "@copy-themes-force",
-        "post-update-cmd": "@copy-themes-force",
+        "post-install-cmd": ["@copy-themes-force", "@dump-modules"],
+        "post-update-cmd": ["@copy-themes-force", "@dump-modules"],
         "phpcs-finc": "vendor/bin/phpcs --standard=tests/finc/phpcs.xml",
-        "copy-themes-force": "php devops/composer/themes.php --force"
+        "copy-themes-force": "php devops/composer/themes.php --force",
+        "dump-modules": "ComposerEventHandlers\\Modules::dump"
+    },
+    "extra": {
+        "vufind": {
+            "modules": [
+                "finc"
+            ]
+        }
     }
 }
\ No newline at end of file

config/application.config.php

 <?php
 
+use ComposerEventHandlers\Modules;
+
 // Set up modules:
 $modules = [
     'Zend\Form', 'Zend\Router', 'ZfcRbac',
@@ -22,6 +24,8 @@ if ($localModules = getenv('VUFIND_LOCAL_MODULES')) {
     }
 }
 
+array_push($modules, ...Modules::get());
+
 // Set up cache directory (be sure to keep separate cache for CLI vs. web and
 // to account for potentially variant environment settings):
 $baseDir = ($local = getenv('VUFIND_LOCAL_DIR')) ? $local : 'data';

devops/composer/modules.php

+<?php
+/**
+ * Copyright (C) 2019  Leipzig University Library
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author  Sebastian Kehr <kehr@ub.uni-leipzig.de>
+ * @license https://opensource.org/licenses/GPL-3.0 GNU GPLv3
+ */
+
+namespace ComposerEventHandlers;
+
+use Composer\Script\Event;
+
+class Modules
+{
+    private const PATH = __DIR__ . '/../../data/cache/modules.php';
+
+    public static function dump(Event $event)
+    {
+        /** @noinspection PhpUndefinedMethodInspection */
+        $extra = $event->getComposer()->getPackage()->getExtra();
+        $modules = var_export($extra['vufind']['modules'] ?? [], true);
+        file_put_contents(self::PATH, "<?php\nreturn $modules;\n");
+    }
+
+    public static function get(): array
+    {
+        /** @noinspection PhpIncludeInspection */
+        return require self::PATH;
+    }
+}
+