Add hook_area_details() to allow modules to provide details about an area.

farm_area.api.php

@@ -49,6 +49,30 @@ function hook_farm_area_links($id) {
   );
 }
 
+/**
+ * Provide details about farm areas.
+ *
+ * @param int $id
+ *   The area id.
+ *
+ * @return array
+ *   Returns a render array to add to the area's popup.
+ */
+function hook_farm_area_details($id) {
+
+  // Start a render array.
+  $output = array();
+
+  // Add "Hello world!" to area details.
+  $output[] = array(
+    '#type' => 'markup',
+    '#markup' => 'Hello world!',
+  );
+
+  // Return the render array.
+  return $output;
+}
+
 /**
  * @}
  */

farm_area.module

@@ -41,6 +41,24 @@ function farm_area_farm_taxonomy_breadcrumb($term) {
   return $breadcrumb;
 }
 
+/**
+ * Generate area details.
+ *
+ * @param int $id
+ *   The area id.
+ *
+ * @return string
+ *   Returns a string of links.
+ */
+function farm_area_get_details($id) {
+
+  // Call out to modules that want to provide links.
+  $area_details = module_invoke_all('farm_area_details', check_plain($id));
+
+  // Render and return.
+  return drupal_render($area_details);
+}
+
 /**
  * Generate area links, sorted by weight.
  *