F copy entity

Summary

Function to copy an entity.

Note to reviewer: This MR depends on f-merge-entities.

Test Environment

There is a unit test.

Check List for the Author

• All automated tests pass
• Reference related Issues
• Up-to-date CHANGELOG.md
• Add type hints in created/changed code
• Annotations in code (Gitlab comments)
  • Intent of new code
  • Problems with old code
  • Why this implementation?

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md
• The test environment setup works and the intended behavior is reproducible in the test environment
• In-code documentation and comments are up-to-date.
• Check: Are there spezifications? Are they satisfied?

For further good practices have a look at our review guidelines.

src/caosdb/common/models.py

@@ -72,6 +72,10 @@ ALL = "ALL"
 NONE = "NONE"
 
 
+SPECIAL_ATTRIBUTES = ["name", "role", "datatype", "description",
+                      "id", "path", "checksum", "size"]
+
+
 class Entity(object):
 
     """Entity is a generic CaosDB object.
@@ -114,6 +118,48 @@ class Entity(object):
         self.id = id
         self.state = None
 
+
+    def copy(self):
+        """
+        Return a copy of entity.
+
+        If deep == True return a deep copy, recursively copying all sub entities.
+
+        Standard properties are copied using add_property.
+        Special attributes, as defined by the global variable SPECIAL_ATTRIBUTES and additionaly
+        the "value" are copied using setattr.
+        """
+        if self.role == "File":
+            new = File()
+        elif self.role == "Property":
+            new = Property()
+        elif self.role == "RecordType":
+            new = RecordType()
+        elif self.role == "Record":
+            new = Record()
+        elif self.role == "Entity":
+            new = Entity()
+        else:
+            raise RuntimeError("Unkonwn role.")
+
+        # Copy special attributes:
+        # TODO: this might rise an exception when copying
+        #       special file attributes like checksum and size.
+        for attribute in SPECIAL_ATTRIBUTES + ["value"]:
+            val = getattr(self, attribute)
+            if val is not None:
+                setattr(new, attribute, val)
+
+        # Copy parents:
+        for p in self.parents:
+            new.add_parent(p)
+
+        # Copy properties:
+        for p in self.properties:
+            new.add_property(p, importance=self.get_importance(p))
+
+        return new
+
     @property
     def version(self):
         if self._version is not None or self._wrapped_entity is None: