Added controller for creating new cases.

src/Controller/CaseController.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Drupal\zencrm\Controller;
+
+use Drupal\Core\Controller\ControllerBase;
+
+/**
+ * Class CaseController.
+ */
+class CaseController extends ControllerBase {
+
+  /**
+   * Displays a form for creating a case. 
+   * The type of case and the hat are prepopulated.
+   *
+   * @return form for creating a case
+   */
+  public function createCaseForHat($hat_id, $case_type_id) {
+    $values = array(
+      'type' => $case_type_id,
+    );
+
+    $case = \Drupal::entityTypeManager()
+      ->getStorage('case_entity')
+      ->create($values);
+
+    $case->hats_involved->appendItem($hat_id);  
+
+    $form = \Drupal::entityTypeManager()
+      ->getFormObject('case_entity', 'default')
+      ->setEntity($case);
+    return \Drupal::formBuilder()->getForm($form);
+  }
+}

zencrm.routing.yml

@@ -21,3 +21,12 @@ zencrm.contact_details.create:
     _title: 'Add New Contact Details'
   requirements:
     _permission: 'access content'
+
+zencrm.case.create:
+  path: '/zencrm/case/{hat_id}/add/{case_type_id}'
+  defaults:
+    _controller: '\Drupal\zencrm\Controller\CaseController::createCaseForHat'
+    _title: 'Add New Case'
+  requirements:
+    _permission: 'access content'
+