Fix 765 - Update to ruamel.yaml 0.17, use new API

docs/conf.py

@@ -185,7 +185,7 @@
  ('py:class', 'Exception'),
  ('py:class', 'collections.OrderedDict'),
 
- ('py:class', 'ruamel.yaml.dumper.SafeDumper'),
+ ('py:class', 'ruamel.yaml.representer.SafeRepresenter'),
  ('py:class', 'rest_framework.serializers.Serializer'),
  ('py:class', 'rest_framework.renderers.BaseRenderer'),
  ('py:class', 'rest_framework.parsers.BaseParser'),

requirements/base.txt

@@ -2,7 +2,7 @@ coreapi>=2.3.3
 coreschema>=0.0.4
 djangorestframework>=3.10.3
 django>=2.2.16
-ruamel.yaml>=0.16.13
+ruamel.yaml>=0.17.2
 inflection>=0.3.1
 packaging>=21.0
 pytz>=2021.1

src/drf_yasg/codecs.py

@@ -2,9 +2,11 @@
 import json
 import logging
 from collections import OrderedDict
+from io import StringIO
 
 from django.utils.encoding import force_bytes
-from ruamel import yaml
+from ruamel.yaml import YAML
+from ruamel.yaml.representer import SafeRepresenter
 
 from . import openapi
 from .errors import SwaggerValidationError
@@ -125,65 +127,37 @@ def _dump_dict(self, spec):
  return json.dumps(spec)
 
 
-YAML_MAP_TAG = u'tag:yaml.org,2002:map'
-
-
-class SaneYamlDumper(yaml.SafeDumper):
- """YamlDumper class usable for dumping ``OrderedDict`` and list instances in a standard way."""
+class SaneYamlRepresenter(SafeRepresenter):
+ """SafeRepresenter class usable for dumping ``OrderedDict`` and list instances in a standard way."""
 
  def ignore_aliases(self, data):
  """Disable YAML references."""
  return True
 
- def increase_indent(self, flow=False, indentless=False, **kwargs):
- """https://stackoverflow.com/a/39681672
+ def represent_text(self, text):
+ """Write multi-line strings in block style."""
+ if "\n" in text:
+ return self.represent_scalar("tag:yaml.org,2002:str", text, style="|")
+ return self.represent_scalar("tag:yaml.org,2002:str", text)
 
- Indent list elements.
- """
- return super(SaneYamlDumper, self).increase_indent(flow=flow, indentless=False, **kwargs)
 
- def represent_odict(self, mapping, flow_style=None): # pragma: no cover
- """https://gist.github.com/miracle2k/3184458
+# Use block style for multi-line strings
+SaneYamlRepresenter.add_representer(str, SaneYamlRepresenter.represent_text)
 
- Make PyYAML output an OrderedDict.
 
- It will do so fine if you use yaml.dump(), but that generates ugly, non-standard YAML code.
+# Avoid YAML !!omap tag for OrderedDict
+SaneYamlRepresenter.add_representer(OrderedDict, SaneYamlRepresenter.represent_dict)
+SaneYamlRepresenter.add_multi_representer(OrderedDict, SaneYamlRepresenter.represent_dict)
 
- To use yaml.safe_dump(), you need the following.
- """
- tag = YAML_MAP_TAG
- value = []
- node = yaml.MappingNode(tag, value, flow_style=flow_style)
- if self.alias_key is not None:
- self.represented_objects[self.alias_key] = node
- best_style = True
- if hasattr(mapping, 'items'):
- mapping = mapping.items()
- for item_key, item_value in mapping:
- node_key = self.represent_data(item_key)
- node_value = self.represent_data(item_value)
- if not (isinstance(node_key, yaml.ScalarNode) and not node_key.style):
- best_style = False
- if not (isinstance(node_value, yaml.ScalarNode) and not node_value.style):
- best_style = False
- value.append((node_key, node_value))
- if flow_style is None:
- if self.default_flow_style is not None:
- node.flow_style = self.default_flow_style
- else:
- node.flow_style = best_style
- return node
-
- def represent_text(self, text):
- if "\n" in text:
- return self.represent_scalar('tag:yaml.org,2002:str', text, style='|')
- return self.represent_scalar('tag:yaml.org,2002:str', text)
+yaml = YAML(typ="safe")
+yaml.Representer = SaneYamlRepresenter
 
+# Add 2 extra spaces when indenting lists
+# https://stackoverflow.com/q/25108581/10612
+yaml.indent(sequence=4, offset=2)
 
-SaneYamlDumper.add_representer(bytes, SaneYamlDumper.represent_text)
-SaneYamlDumper.add_representer(str, SaneYamlDumper.represent_text)
-SaneYamlDumper.add_representer(OrderedDict, SaneYamlDumper.represent_odict)
-SaneYamlDumper.add_multi_representer(OrderedDict, SaneYamlDumper.represent_odict)
+# Do not sort dicts by keys in Representer.represent_dict
+sort_base_mapping_type_on_output = False
 
 
 def yaml_sane_dump(data, binary):
@@ -199,16 +173,13 @@ def yaml_sane_dump(data, binary):
  :return: the serialized YAML
  :rtype: str or bytes
  """
- return yaml.dump(data, Dumper=SaneYamlDumper, default_flow_style=False, encoding='utf-8' if binary else None)
-
-
-class SaneYamlLoader(yaml.SafeLoader):
- def construct_odict(self, node, deep=False):
- self.flatten_mapping(node)
- return OrderedDict(self.construct_pairs(node))
-
-
-SaneYamlLoader.add_constructor(YAML_MAP_TAG, SaneYamlLoader.construct_odict)
+ out = StringIO()
+ yaml.dump(data, stream=out)
+ contents = out.getvalue()
+ out.close()
+ if binary:
+ return contents.encode()
+ return contents
 
 
 def yaml_sane_load(stream):
@@ -217,7 +188,7 @@ def yaml_sane_load(stream):
  :param stream: YAML stream (can be a string or a file-like object)
  :rtype: OrderedDict
  """
- return yaml.load(stream, Loader=SaneYamlLoader)
+ return yaml.load(stream)
 
 
 class OpenAPICodecYaml(_OpenAPICodec):