import copy import json import logging from collections import OrderedDict from django.utils.encoding import force_bytes from ruamel import yaml from . import openapi from .errors import SwaggerValidationError logger = logging.getLogger(__name__) def _validate_flex(spec): try: from flex.core import parse as validate_flex from flex.exceptions import ValidationError except ImportError: return try: validate_flex(spec) except ValidationError as ex: raise SwaggerValidationError(str(ex)) from ex def _validate_swagger_spec_validator(spec): from swagger_spec_validator.common import SwaggerValidationError as SSVErr from swagger_spec_validator.validator20 import validate_spec as validate_ssv try: validate_ssv(spec) except SSVErr as ex: raise SwaggerValidationError(str(ex)) from ex #: VALIDATORS = { 'flex': _validate_flex, 'ssv': _validate_swagger_spec_validator, } class _OpenAPICodec(object): media_type = None def __init__(self, validators): self._validators = validators @property def validators(self): """List of validator names to apply""" return self._validators def encode(self, document): """Transform an :class:`.Swagger` object to a sequence of bytes. Also performs validation and applies settings. :param openapi.Swagger document: Swagger spec object as generated by :class:`.OpenAPISchemaGenerator` :return: binary encoding of ``document`` :rtype: bytes """ if not isinstance(document, openapi.Swagger): raise TypeError('Expected a `openapi.Swagger` instance') spec = self.generate_swagger_object(document) errors = {} for validator in self.validators: try: # validate a deepcopy of the spec to prevent the validator from messing with it # for example, swagger_spec_validator adds an x-scope property to all references VALIDATORS[validator](copy.deepcopy(spec)) except SwaggerValidationError as e: errors[validator] = str(e) if errors: exc = SwaggerValidationError("spec validation failed: {}".format(errors), errors, spec, self) logger.warning(str(exc)) raise exc return force_bytes(self._dump_dict(spec)) def encode_error(self, err): """Dump an error message into an encoding-appropriate sequence of bytes""" return force_bytes(self._dump_dict(err)) def _dump_dict(self, spec): """Dump the given dictionary into its string representation. :param dict spec: a python dict :return: string representation of ``spec`` :rtype: str or bytes """ raise NotImplementedError("override this method") def generate_swagger_object(self, swagger): """Generates the root Swagger object. :param openapi.Swagger swagger: Swagger spec object as generated by :class:`.OpenAPISchemaGenerator` :return: swagger spec as dict :rtype: OrderedDict """ return swagger.as_odict() class OpenAPICodecJson(_OpenAPICodec): media_type = 'application/json' def __init__(self, validators, pretty=False, media_type='application/json'): super(OpenAPICodecJson, self).__init__(validators) self.pretty = pretty self.media_type = media_type def _dump_dict(self, spec): """Dump ``spec`` into JSON. :rtype: str""" if self.pretty: out = json.dumps(spec, indent=4, separators=(',', ': '), ensure_ascii=False) if out[-1] != '\n': out += '\n' return out else: return json.dumps(spec, ensure_ascii=False) 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.""" def ignore_aliases(self, data): """Disable YAML references.""" return True def increase_indent(self, flow=False, indentless=False, **kwargs): """https://stackoverflow.com/a/39681672 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 Make PyYAML output an OrderedDict. It will do so fine if you use yaml.dump(), but that generates ugly, non-standard YAML code. 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) 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) def yaml_sane_dump(data, binary): """Dump the given data dictionary into a sane format: * OrderedDicts are dumped as regular mappings instead of non-standard !!odict * multi-line mapping style instead of json-like inline style * list elements are indented into their parents * YAML references/aliases are disabled :param dict data: the data to be dumped :param bool binary: True to return a utf-8 encoded binary object, False to return a string :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, allow_unicode=binary ) 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) def yaml_sane_load(stream): """Load the given YAML stream while preserving the input order for mapping items. :param stream: YAML stream (can be a string or a file-like object) :rtype: OrderedDict """ return yaml.load(stream, Loader=SaneYamlLoader) class OpenAPICodecYaml(_OpenAPICodec): media_type = 'application/yaml' def __init__(self, validators, media_type='application/yaml'): super(OpenAPICodecYaml, self).__init__(validators) self.media_type = media_type def _dump_dict(self, spec): """Dump ``spec`` into YAML. :rtype: bytes""" return yaml_sane_dump(spec, binary=True)