Allow modules to define dashboard groups per layout region.

modules/ui/dashboard/farm_ui_dashboard.api.php

@@ -57,6 +57,40 @@ function hook_farm_dashboard_panes() {
   ];
 }
 
+/**
+ * Defines farm dashboard groups.
+ *
+ * @return array
+ *   Returns an array of farm dashboard groups keyed by layout region.
+ */
+function hook_farm_dashboard_groups() {
+  return [
+
+    // Returns an associate array keyed by the layout region.
+    // Options are top, first, second, or bottom.
+    'first' => [
+
+      // Groups are defined as a render array keyed with a unique group
+      // machine name.
+      'my_group' => [
+
+        // The type. Defaults to container.
+        '#type' => 'details',
+
+        // Optionally specify a title.
+        '#title' => t('My group title'),
+
+        // Optionally specify a weight for sorting.
+        '#weight' => 100,
+      ],
+
+    ],
+    'bottom' => [
+      // Define groups for the bottom layout region.
+    ],
+  ];
+}
+
 /**
  * @} End of "addtogroup hooks".
  */

modules/ui/dashboard/src/Controller/DashboardController.php

@@ -47,7 +47,8 @@ class DashboardController extends ControllerBase {
   public function dashboard() {
 
     // Start a build array.
-    $build = [];
+    // Ask modules for dashboard groups.
+    $build = $this->moduleHandler()->invokeAll('farm_dashboard_groups');
 
     // Ask modules for dashboard panes.
     $panes = $this->moduleHandler()->invokeAll('farm_dashboard_panes');