diff --git a/src/Plugin/views/field/SearchApiFieldTrait.php b/src/Plugin/views/field/SearchApiFieldTrait.php
index fbd563b..c320add 100644
--- a/src/Plugin/views/field/SearchApiFieldTrait.php
+++ b/src/Plugin/views/field/SearchApiFieldTrait.php
@@ -9,6 +9,7 @@
 use Drupal\Core\TypedData\DataReferenceInterface;
 use Drupal\Core\TypedData\ListInterface;
 use Drupal\search_api\Plugin\views\SearchApiHandlerTrait;
+use Drupal\search_api\Processor\ConfigurablePropertyInterface;
 use Drupal\search_api\Processor\ProcessorPropertyInterface;
 use Drupal\search_api\Utility\Utility;
 use Drupal\views\Plugin\views\field\MultiItemsFieldHandlerInterface;
@@ -209,7 +210,6 @@ protected function addRetrievedProperty($combined_property_path) {
     $this->getQuery()->addRetrievedProperty($combined_property_path);
 
     list($datasource_id, $property_path) = Utility::splitCombinedId($combined_property_path);
-    // If $datasource_id is NULL, it will be an empty string key in the array.
     $this->retrievedProperties[$datasource_id][$property_path] = $combined_property_path;
     return $this;
   }
@@ -289,6 +289,7 @@ public function getValue(ResultRow $values, $field = NULL) {
    * @see \Drupal\views\Plugin\views\field\FieldHandlerInterface::preRender()
    */
   public function preRender(&$values) {
+    $index = $this->getIndex();
     // We deal with the properties one by one, always loading the necessary
     // values for any nested properties coming afterwards.
     // @todo This works quite well, but will load each item/entity individually.
@@ -300,6 +301,9 @@ public function preRender(&$values) {
     //   expandRequiredProperties() would have to provide more information, or
     //   provide a separate properties list for each row.
     foreach ($this->expandRequiredProperties() as $datasource_id => $properties) {
+      if ($datasource_id === '') {
+        $datasource_id = NULL;
+      }
       foreach ($properties as $property_path => $combined_property_path) {
         // Determine the path of the parent property, and the property key to
         // take from it for this property. If the name is "_object", we just
@@ -316,7 +320,7 @@ public function preRender(&$values) {
           // Bail for rows with the wrong datasource for this property, or for
           // which this field doesn't even apply (which will usually be the
           // same, though).
-          if (($datasource_id && $datasource_id != $row->search_api_datasource) || !$this->isActiveForRow($row)) {
+          if (!$this->isActiveForRow($row)) {
             continue;
           }
           // Check whether there are parent objects present. If no, either load
@@ -356,6 +360,30 @@ public function preRender(&$values) {
               if (!($parent instanceof ComplexDataInterface)) {
                 continue;
               }
+              // Check whether this is a processor-generated property and use
+              // special code to retrieve it in this case.
+              $definitions = $index->getPropertyDefinitions($datasource_id);
+              if (!$parent_path && isset($definitions[$name])) {
+                $definition = $definitions[$name];
+                if ($definition instanceof ProcessorPropertyInterface) {
+                  // @todo Create dummy field and put it in dummy item, then use
+                  //   the processor to add the field's values. See code for
+                  //   extracting processor-generated properties in
+                  //   \Drupal\search_api\Processor\ProcessorPluginBase::extractItemValues().
+                  if ($set_values) {
+                    $row->{$combined_property_path} = array();
+                  }
+                  foreach ($dummy_field->getValues() as $value) {
+                    if ($set_values) {
+                      $row->{$combined_property_path}[] = $value;
+                    }
+                    $typed_data = \Drupal::service('typed_data_manager')
+                      ->create($definition, $value);
+                    $row->_relationship_objects[$property_path][] = $typed_data;
+                  }
+                  continue;
+                }
+              }
               // Add the typed data for the property to our relationship objects
               // for this property path. To treat list properties correctly
               // regarding possible child properties, add all the list items
@@ -392,21 +420,6 @@ public function preRender(&$values) {
                 // that only exists on a different bundle. Unfortunately, there
                 // is no ComplexDataInterface::hasProperty() method, so we can
                 // only catch and ignore the exception.
-                if (empty($datasource_id)) {
-                  $item = $row->_item;
-
-                  $definitions = $item->getIndex()->getPropertyDefinitions();
-                  if (isset($definitions[$name]) && $definitions[$name] instanceof ProcessorPropertyInterface) {
-                    $field = $item->getField($name);
-                    $field_values = $item->getField($name)->getValues();
-                    $row->_relationship_objects[$property_path] = [
-                      \Drupal::service('typed_data_manager')->create(
-                        $field->getDataDefinition(),
-                        reset($field_values)
-                      ),
-                    ];
-                  }
-                }
               }
             }
           }
@@ -451,6 +464,9 @@ public function preRender(&$values) {
   protected function expandRequiredProperties() {
     $required_properties = array();
     foreach ($this->retrievedProperties as $datasource_id => $properties) {
+      if ($datasource_id === '') {
+        $datasource_id = NULL;
+      }
       foreach (array_keys($properties) as $property_path) {
         $path_to_add = '';
         foreach (explode(':', $property_path) as $component) {
@@ -477,8 +493,8 @@ protected function expandRequiredProperties() {
    *   otherwise.
    */
   protected function isActiveForRow(ResultRow $row) {
-    $datasource_id = $this->getDatasourceId();
-    return !$datasource_id || $row->search_api_datasource === $datasource_id;
+    $datasource_ids = array(NULL, $row->search_api_datasource);
+    return in_array($this->getDatasourceId(), $datasource_ids, TRUE);
   }
 
   /**
diff --git a/src/Utility/Utility.php b/src/Utility/Utility.php
index 6937e50..f247c90 100644
--- a/src/Utility/Utility.php
+++ b/src/Utility/Utility.php
@@ -421,7 +421,7 @@ public static function deepCopy(array $array) {
    *   \Drupal\search_api\IndexInterface::DATASOURCE_ID_SEPARATOR.
    */
   public static function createCombinedId($datasource_id, $raw_id) {
-    if (empty($datasource_id)) {
+    if (!isset($datasource_id)) {
       return $raw_id;
     }
     return $datasource_id . IndexInterface::DATASOURCE_ID_SEPARATOR . $raw_id;