WIP: Add `empty_diff` function to apiutils

src/caosdb/apiutils.py

@@ -188,9 +188,8 @@ def getCommitIn(folder):
         return t.readline().strip()
 
 
-def compare_entities(old_entity: Entity, new_entity: Entity):
-    """
-    Compare two entites.
+def compare_entities(old_entity: Entity, new_entity: Entity, compare_referenced_records: bool = False):
+    """Compare two entites.
 
     Return a tuple of dictionaries, the first index belongs to additional information for old
     entity, the second index belongs to additional information for new entity.
@@ -204,6 +203,20 @@ def compare_entities(old_entity: Entity, new_entity: Entity):
         - ... value (not implemented yet)
         In case of changed information the value listed under the respective key shows the
         value that is stored in the respective entity.
+
+    If `compare_referenced_records` is `True`, also referenced entities will be
+    compared using this function, but with `compare_referenced_records = False`
+    to prevent infinite recursion in case of circular references.
+
+    Parameters
+    ----------
+    old_entity, new_entity : Entity
+        Entities to be compared
+    compare_referenced_records : bool, optional
+        Whether to compare referenced records in case of both, `old_entity` and
+        `new_entity`, have the same reference properties and both have a Record
+        object as value.
+
     """
     olddiff: Dict[str, Any] = {"properties": {}, "parents": []}
     newdiff: Dict[str, Any] = {"properties": {}, "parents": []}
@@ -300,6 +313,31 @@ def compare_entities(old_entity: Entity, new_entity: Entity):
     return (olddiff, newdiff)
 
 
+def empty_diff(old_entity: Entity, new_entity: Entity, compare_referenced_records: bool = False):
+    """Check whether the `compare_entities` found any differences between
+    old_entity and new_entity.
+
+    Parameters
+    ----------
+    old_entity, new_entity : Entity
+        Entities to be compared
+    compare_referenced_records : bool, optional
+        Whether to compare referenced records in case of both, `old_entity` and
+        `new_entity`, have the same reference properties and both have a Record
+        object as value.
+
+    """
+    olddiff, newdiff = compare_entities(
+        old_entity, new_entity, compare_referenced_records)
+    for diff in [olddiff, newdiff]:
+        for key in diff:
+            if len(diff[key]) > 0:
+                # There is a difference somewhere in the diff
+                return False
+    # all elements of the two diffs were empty
+    return True
+
+
 def merge_entities(entity_a: Entity, entity_b: Entity):
     """
     Merge entity_b into entity_a such that they have the same parents and properties.