Issue #402: Validate URLs entered into field_paragraph_document_link

html/modules/custom/bc_dc/bc_dc.module

@@ -703,6 +703,13 @@ function bc_dc_cron(): void {
   \Drupal::service('bc_dc.update_review_status')->updateAll();
 }
 
+/**
+ * Implements hook_entity_type_alter().
+ */
+function bc_dc_entity_type_alter(array &$entity_types): void {
+  $entity_types['paragraph']->addConstraint('BcDcUrlConstraint');
+}
+
 /**
  * Implements hook_form_FORM_ID_alter().
  */

html/modules/custom/bc_dc/src/Plugin/Validation/Constraint/BcDcUrlConstraint.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace Drupal\bc_dc\Plugin\Validation\Constraint;
+
+use Symfony\Component\Validator\Constraint;
+
+/**
+ * Checks that a string is a URL.
+ *
+ * @Constraint(
+ *   id = "BcDcUrlConstraint",
+ *   label = @Translation("BCDC URL validator", context = "Validation"),
+ *   type = "string"
+ * )
+ */
+class BcDcUrlConstraint extends Constraint {
+
+  /**
+   * Constraint message.
+   *
+   * @var string
+   */
+  public $message = 'Enter a valid URL.';
+
+}

html/modules/custom/bc_dc/src/Plugin/Validation/Constraint/BcDcUrlConstraintValidator.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace Drupal\bc_dc\Plugin\Validation\Constraint;
+
+use Symfony\Component\Validator\Constraint;
+use Symfony\Component\Validator\ConstraintValidator;
+
+/**
+ * Validates the BcDcUrlConstraint constraint.
+ */
+class BcDcUrlConstraintValidator extends ConstraintValidator {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function validate(mixed $value, Constraint $constraint): void {
+    // This will be a string in kernel tests.
+    if (is_object($value)) {
+      $url = $value->field_paragraph_document_link?->value;
+    }
+    else {
+      $url = (string) $value;
+    }
+
+    // If there is a URL, it must pass parse_url() and the regex.
+    if ($url && (parse_url($url) === FALSE || !preg_match(',^(//|\\\\|(file|https?|ftps?):),', $url))) {
+      $this->context->addViolation($constraint->message);
+    }
+  }
+
+}

html/modules/custom/bc_dc/tests/src/Kernel/BcDcKernelTest.php

@@ -0,0 +1,68 @@
+<?php
+
+namespace Drupal\Tests\bc_dc\Kernel;
+
+use Drupal\Core\TypedData\DataDefinition;
+use Drupal\KernelTests\KernelTestBase;
+
+/**
+ * Kernel tests.
+ *
+ * @group BcDc
+ */
+class BcDcKernelTest extends KernelTestBase {
+
+  /**
+   * The typed data manager to use.
+   *
+   * @var \Drupal\Core\TypedData\TypedDataManager
+   */
+  protected $typedData;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    $this->enableModules(['bc_dc', 'paragraphs']);
+    $this->typedData = $this->container->get('typed_data_manager');
+  }
+
+  /**
+   * Test validation constraints.
+   */
+  public function testValidation() {
+    // Create a definition that specifies some AllowedValues.
+    $definition = DataDefinition::create('string')
+      ->addConstraint('BcDcUrlConstraint');
+
+    // Valid paths.
+    $paths = [
+      'http://example.com/path',
+      'https://example.com/path',
+      'ftp://example.com/path',
+      'ftps://example.com/path',
+      'file:///path/filename.pdf',
+      '//test/path',
+      '\\fin.gov.bc.ca\PATH\file_name.pdf',
+    ];
+    foreach ($paths as $path) {
+      $typed_data = $this->typedData->create($definition, $path);
+      $violations = $typed_data->validate();
+      $this->assertEquals(0, $violations->count(), 'Validation should pass for valid path: ' . $path);
+    }
+
+    // Invalid paths.
+    $paths = [
+      'test-path',
+      'mailto:[email protected]',
+      'tel:+12345678901',
+    ];
+    foreach ($paths as $path) {
+      $typed_data = $this->typedData->create($definition, $path);
+      $violations = $typed_data->validate();
+      $this->assertEquals(1, $violations->count(), 'Validation should fail for invalid path: ' . $path);
+    }
+  }
+
+}