feat(expressions): add const expression

src/flextype/core/Entries/Expressions/ConstExpression.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+ /**
+ * Flextype - Hybrid Content Management System with the freedom of a headless CMS 
+ * and with the full functionality of a traditional CMS!
+ * 
+ * Copyright (c) Sergey Romanenko (https://awilum.github.io)
+ *
+ * Licensed under The MIT License.
+ *
+ * For full copyright and license information, please see the LICENSE
+ * Redistributions of files must retain the above copyright notice.
+ */
+
+namespace Flextype\Entries\Expressions;
+
+use Symfony\Component\ExpressionLanguage\ExpressionFunction;
+use Symfony\Component\ExpressionLanguage\ExpressionFunctionProviderInterface;
+
+class ConstExpression implements ExpressionFunctionProviderInterface
+{
+    public function getFunctions()
+    {
+        return [
+            new ExpressionFunction('const', fn(string $const) => "defined($const) ? constant($const) : ''", fn($arguments, string $const) => defined($const) ? constant($const) : '')
+        ];
+    }
+}

src/flextype/settings.yaml

@@ -116,6 +116,9 @@ entries:
     field:
       enabled: true
       class: "Flextype\\Entries\\Expressions\\FieldExpression"
+    const:
+      enabled: true
+      class: "Flextype\\Entries\\Expressions\\ConstExpression"
   directives:
     expressions:
       enabled: true

tests/fixtures/settings/settings.yaml

@@ -112,6 +112,9 @@ entries:
     field:
       enabled: true
       class: "Flextype\\Entries\\Expressions\\FieldExpression"
+    const:
+      enabled: true
+      class: "Flextype\\Entries\\Expressions\\ConstExpression"
   directives:
     expressions:
       enabled: true

tests/src/flextype/core/Entries/Expressions/ConstExpressionTest.php

@@ -0,0 +1,17 @@
+<?php
+
+use Flextype\Component\Filesystem\Filesystem;
+
+beforeEach(function() {
+    filesystem()->directory(PATH['project'] . '/entries')->create();
+});
+
+afterEach(function (): void {
+    filesystem()->directory(PATH['project'] . '/entries')->delete();
+});
+
+test('const expression', function () {
+    define('test-expression-const', 'Foo');
+    entries()->create('const', ['test' => '[[ const("test-expression-const") ]]']);
+    expect(entries()->fetch('const')['test'])->toBe('Foo');
+});