1 files changed, 9 insertions, 5 deletions
diff --git a/core/models/survex.py b/core/models/survex.py
index 835d31d..2ca7412 100644
--- a/core/models/survex.py
+++ b/core/models/survex.py
@@ -12,16 +12,17 @@ from django.urls import reverse
 
 
 class SurvexDirectory(models.Model):
-    """This relates a Cave to the primary SurvexFile which is the 'head' of the survex tree for
-    that cave. Surely this could just be a property of Cave ? No. Several subdirectories
-    all relate to the same Cave
+    """This relates a survexfile (identified by path) to the primary SurvexFile 
+    which is the 'head' of the survex tree for that cave. 
+    Surely this could just be a property of Cave ? No. Several subdirectories
+    all relate to the same Cave.
+    
+    But it *could* be a property of SurvexFile
     """
     path = models.CharField(max_length=200) 
-    # cave = models.ForeignKey("Cave", blank=True, null=True, on_delete=models.SET_NULL) # apparently NEVER USED
     primarysurvexfile = models.ForeignKey(
         "SurvexFile", related_name="primarysurvexfile", blank=True, null=True, on_delete=models.SET_NULL
     )
-    # could also include files in directory but not referenced
 
     class Meta:
         ordering = ("id",)
@@ -37,6 +38,9 @@ class SurvexDirectory(models.Model):
 class SurvexFile(models.Model):
     path = models.CharField(max_length=200)
     survexdirectory = models.ForeignKey("SurvexDirectory", blank=True, null=True, on_delete=models.SET_NULL)
+    primary = models.ForeignKey(
+        "SurvexFile", related_name="primarysurvex", blank=True, null=True, on_delete=models.SET_NULL
+        )
     cave = models.ForeignKey("Cave", blank=True, null=True, on_delete=models.SET_NULL)
 
     class Meta: