updated copy semantics to match rich-text's deepcopy change

Author: sachinrekhi

README.md

@@ -68,14 +68,14 @@ python setup.py test
 
 ## API Reference
 
-Fully implements the original [ottypes/rich-text](https://github.com/ottypes/rich-text) interface. So feel free to use their [API reference](https://github.com/ottypes/rich-text).
+Fully implements the original [ottypes/rich-text](https://github.com/ottypes/rich-text) interface. So feel free to use its [API reference](https://github.com/ottypes/rich-text).
 
 ## References
 - [High-Latency, Low-Bandwidth Windowing in the Jupiter Collaboration System, 1995](http://lively-kernel.org/repository/webwerkstatt/projects/Collaboration/paper/Jupiter.pdf)
 - [Google Wave Operational Transformation, 2010](http://wave-protocol.googlecode.com/hg/whitepapers/operational-transform/operational-transform.html)
 - [Wikipedia: Operational Transformation](https://en.wikipedia.org/wiki/Operational_transformation)
 - [ottypes/rich-text](https://github.com/ottypes/rich-text)
-- [Quill Rich Text Editor](https://github.com/quilljs/quill/) - WYSIWYG Javascript Editor that products Delta objects on user changes
+- [Quill Rich Text Editor](https://github.com/quilljs/quill/) - WYSIWYG Javascript Editor that produces Delta objects on changes
 - [ShareJS](https://github.com/share/ShareJS) - NodeJS server that implements the OT collaboration protocol
 
 ## License

richtextpy/delta.py

@@ -7,7 +7,7 @@
 from copy import deepcopy
 from diff_match_patch import diff_match_patch
 from type_utils import is_list, is_string, is_dict, is_number, INFINITY
-from op import op_length, op_clone, op_insert_string, attr_compose, attr_transform, attr_diff
+from op import op_length, op_insert_string, attr_compose, attr_transform, attr_diff
 from opiterator import OpIterator
 
 
@@ -68,7 +68,7 @@ def push(self, op):
 		# this requires combining same operation types when possible
 		# and re-ordering same-index inserts and deletes to ensure canonical order
 
-		new_op = op_clone(op)
+		new_op = deepcopy(op)
 
 		# if no existing ops, simply add new_op
 		if len(self.ops) == 0:

richtextpy/op.py

@@ -15,19 +15,6 @@ def op_length(op):
 	elif 'retain' in op:
 		return op['retain']
 
-def op_clone(op):
-	if not is_dict(op):
-		return dict()
-
-	cloned_op = deepcopy(op)
-	
-	# remove top-level null keys
-	for key in cloned_op:
-		if cloned_op[key] == None:
-			del cloned_op[key]
-
-	return cloned_op
-
 def op_insert_string(op):
 	if 'insert' in op:
 		if is_string(op['insert']):
@@ -37,26 +24,22 @@ def op_insert_string(op):
 
 	raise Exception('Diff called on a non-document')
 
-def attr_clone(attributes, keep_null):
-	if not is_dict(attributes):
-		return dict()
-
-	cloned_attributes = dict()
-	for key in attributes.keys():
-		if (attributes[key] != None) or keep_null:
-			cloned_attributes[key] = attributes[key]
-
-	return cloned_attributes
-
 def attr_compose(a, b, keep_null):
 	if not is_dict(a):
 		a = dict()
 	if not is_dict(b):
 		b = dict()
-	attributes = attr_clone(b, keep_null)
+
+	attributes = deepcopy(b)
+	if not keep_null:
+		for key in attributes.keys():
+			if attributes[key] == None:
+				del attributes[key]
+
 	for key in a.keys():
 		if key not in b:
 			attributes[key] = a[key]
+	
 	if len(attributes.keys()) > 0:
 		return attributes
 	else:

tests/test_delta.py

@@ -571,6 +571,14 @@ def test_diff(self):
 		expected = Delta().insert({'image': 'http://quilljs.com'}).delete(1)
 		self.assertEqual(a.diff(b), expected)
 
+		# embed object change
+		embed = {'image': 'http://quilljs.com'}
+		a = Delta().insert(embed)
+		embed['image'] = 'http://github.com'
+		b = Delta().insert(embed)
+		expected = Delta().insert({'image': 'http://github.com'}).delete(1)
+		self.assertEqual(a.diff(b), expected)
+
 		# embed false positive
 		a = Delta().insert(1)
 		b = Delta().insert(chr(0)) # Placeholder char for embed in diff()