Source code for drf_yasg.codecs

from six import raise_from

import copy
import json
import logging
from collections import OrderedDict

from coreapi.compat import force_bytes
from ruamel import yaml

from . import openapi
from .errors import SwaggerValidationError

logger = logging.getLogger(__name__)

def _validate_flex(spec):
        from flex.core import parse as validate_flex
        from flex.exceptions import ValidationError
    except ImportError:

    except ValidationError as ex:
        raise_from(SwaggerValidationError(str(ex)), ex)

def _validate_swagger_spec_validator(spec):
    from swagger_spec_validator.validator20 import validate_spec as validate_ssv
    from swagger_spec_validator.common import SwaggerValidationError as SSVErr
    except SSVErr as ex:
        raise_from(SwaggerValidationError(str(ex)), ex)

    'flex': _validate_flex,
    'ssv': _validate_swagger_spec_validator,

class _OpenAPICodec(object):
    media_type = None

    def __init__(self, validators):
        self._validators = validators

    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:
                # 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
            except SwaggerValidationError as e:
                errors[validator] = str(e)

        if errors:
            exc = SwaggerValidationError("spec validation failed: {}".format(errors), errors, spec, self)
            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()

[docs]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=(',', ': ')) if out[-1] != '\n': out += '\n' return out else: return json.dumps(spec)
YAML_MAP_TAG = u',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): """ 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 """ 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 best_style = False if not (isinstance(node_value, yaml.ScalarNode) and not 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 SaneYamlDumper.add_representer(OrderedDict, SaneYamlDumper.represent_odict) SaneYamlDumper.add_multi_representer(OrderedDict, SaneYamlDumper.represent_odict)
[docs]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)
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)
[docs]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)
[docs]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)