#8 Map to migrate Pitches when migrating a Route.

sites/all/modules/custom/migrate_climbnz/migrate_climbnz.node.route.inc

@@ -41,6 +41,14 @@ class ClimbNZRouteMigration extends DrupalNode6Migration {
     $this->addFieldMapping('field_ascent', 'field_ascent');
 
     $this->addFieldMapping('field_attribution', 'field_attribution');
+
+    $this->addFieldMapping('field_pitches', 'field_pitch')
+      ->sourceMigration('Pitch');
+  }
+
+  public function getPitchByTitle($title) {
+    $result = db_query("SELECT nid FROM {node} WHERE title=:title", array(':title' => $title))->fetchField();
+    return $result;
   }
 
   public function prepareRow($row) {
@@ -50,5 +58,12 @@ class ClimbNZRouteMigration extends DrupalNode6Migration {
       return FALSE;
     }
 
+    // Map to child pitches via compound key of route nid and pitch field delta.
+    // A callback for field_pitches is too late, due to migrate sourceMigration magic.
+    if (count($row->field_pitch)) {
+      foreach ($row->field_pitch as $key => $bogus) {
+        $row->field_pitch[$key] = array('nid' => $row->nid, 'delta' => $key);
+      }
+    }
   }
 }