diff --git a/src/Processor/ProcessorPluginBase.php b/src/Processor/ProcessorPluginBase.php
index 1cfab67..db715d8 100644
--- a/src/Processor/ProcessorPluginBase.php
+++ b/src/Processor/ProcessorPluginBase.php
@@ -217,26 +217,28 @@ protected function filterForPropertyPath(array $fields, $property_path) {
    *   put under in the return value.
    * @param bool $load
    *   (optional) If FALSE, only field values already present will be returned.
-   *   Otherwise, fields will be loaded if necessary.
+   *   Otherwise, fields will be extracted (and underlying objects loaded) if
+   *   necessary.
    *
    * @return mixed[][][]
    *   Arrays of field values, keyed by items' indexes in $items and the given
    *   field IDs from $required_properties.
    */
   protected function extractItemValues(array $items, array $required_properties, $load = TRUE) {
-    $ret = array();
+    $extracted_values = array();
 
     foreach ($items as $i => $item) {
-      $property_values = array();
+      $item_values = array();
       /** @var \Drupal\search_api\Item\FieldInterface[][] $missing_fields */
       $missing_fields = array();
       $processor_fields = array();
       $needed_processors = array();
       foreach (array(NULL, $item->getDatasourceId()) as $datasource_id) {
-        $properties = $this->index->getPropertyDefinitions($datasource_id);
         if (empty($required_properties[$datasource_id])) {
           continue;
         }
+
+        $properties = $this->index->getPropertyDefinitions($datasource_id);
         foreach ($required_properties[$datasource_id] as $property_path => $combined_id) {
           // If a field with the right property path is already set on the item,
           // use it. This might actually make problems in case the values have
@@ -245,13 +247,13 @@ protected function extractItemValues(array $items, array $required_properties, $
           // problem in most situations.
           foreach ($this->filterForPropertyPath($item->getFields(FALSE), $property_path) as $field) {
             if ($field->getDatasourceId() === $datasource_id) {
-              $property_values[$combined_id] = $field->getValues();
+              $item_values[$combined_id] = $field->getValues();
               continue 2;
             }
           }
 
-          // Field/property value is not present on the item. Stop here if we
-          // don't want to load anything.
+          // There are no values present on the item for this property. If we
+          // don't want to extract any fields, skip it.
           if (!$load) {
             continue;
           }
@@ -276,7 +278,7 @@ protected function extractItemValues(array $items, array $required_properties, $
           }
           else {
             // Extracting properties without a datasource is pointless.
-            $property_values[$combined_id] = array();
+            $item_values[$combined_id] = array();
           }
         }
       }
@@ -284,7 +286,7 @@ protected function extractItemValues(array $items, array $required_properties, $
         Utility::extractFields($item->getOriginalObject(), $missing_fields);
         foreach ($missing_fields as $property_fields) {
           foreach ($property_fields as $field) {
-            $property_values[$field->getFieldIdentifier()] = $field->getValues();
+            $item_values[$field->getFieldIdentifier()] = $field->getValues();
           }
         }
       }
@@ -299,14 +301,14 @@ protected function extractItemValues(array $items, array $required_properties, $
           }
         }
         foreach ($processor_fields as $field) {
-          $property_values[$field->getFieldIdentifier()] = $field->getValues();
+          $item_values[$field->getFieldIdentifier()] = $field->getValues();
         }
       }
 
-      $ret[$i] = $property_values;
+      $extracted_values[$i] = $item_values;
     }
 
-    return $ret;
+    return $extracted_values;
   }
 
   /**