feat: support action expression parsing, validation, and evaluation

app/TransactionRules/Expressions/ActionExpressionLanguageProvider.php

@@ -0,0 +1,37 @@
+<?php
+
+/**
+ * ActionExpressionLanguageProvider.php
+ * Copyright (c) 2024 Michael Thomas
+ *
+ * This file is part of Firefly III (https://github.com/firefly-iii).
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+namespace FireflyIII\TransactionRules\Expressions;
+
+use Symfony\Component\ExpressionLanguage\ExpressionFunction;
+use Symfony\Component\ExpressionLanguage\ExpressionFunctionProviderInterface;
+
+class ActionExpressionLanguageProvider implements ExpressionFunctionProviderInterface
+{
+    public function getFunctions(): array
+    {
+        return [
+            ExpressionFunction::fromPhp("substr"),
+            ExpressionFunction::fromPhp("strlen")
+        ];
+    }
+}