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| 1 | +# Copyright 2018-Present The CloudEvents Authors |
| 2 | +# |
| 3 | +# Licensed under the Apache License, Version 2.0 (the "License"); you may |
| 4 | +# not use this file except in compliance with the License. You may obtain |
| 5 | +# a copy of the License at |
| 6 | +# |
| 7 | +# http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | +# |
| 9 | +# Unless required by applicable law or agreed to in writing, software |
| 10 | +# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| 11 | +# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| 12 | +# License for the specific language governing permissions and limitations |
| 13 | +# under the License. |
| 14 | + |
| 15 | +import re |
| 16 | +from collections import defaultdict |
| 17 | +from datetime import datetime |
| 18 | +from typing import Any, Final, Optional |
| 19 | + |
| 20 | +from cloudevents.core.v1.exceptions import ( |
| 21 | + BaseCloudEventException, |
| 22 | + CloudEventValidationError, |
| 23 | + CustomExtensionAttributeError, |
| 24 | + InvalidAttributeTypeError, |
| 25 | + InvalidAttributeValueError, |
| 26 | + MissingRequiredAttributeError, |
| 27 | +) |
| 28 | + |
| 29 | +REQUIRED_ATTRIBUTES: Final[list[str]] = ["id", "source", "type", "specversion"] |
| 30 | +OPTIONAL_ATTRIBUTES: Final[list[str]] = [ |
| 31 | + "datacontenttype", |
| 32 | + "dataschema", |
| 33 | + "subject", |
| 34 | + "time", |
| 35 | +] |
| 36 | + |
| 37 | + |
| 38 | +class CloudEvent: |
| 39 | + """ |
| 40 | + The CloudEvent Python wrapper contract exposing generically-available |
| 41 | + properties and APIs. |
| 42 | +
|
| 43 | + Implementations might handle fields and have other APIs exposed but are |
| 44 | + obliged to follow this contract. |
| 45 | + """ |
| 46 | + |
| 47 | + def __init__(self, attributes: dict[str, Any], data: Optional[dict] = None) -> None: |
| 48 | + """ |
| 49 | + Create a new CloudEvent instance. |
| 50 | +
|
| 51 | + :param attributes: The attributes of the CloudEvent instance. |
| 52 | + :param data: The payload of the CloudEvent instance. |
| 53 | +
|
| 54 | + :raises ValueError: If any of the required attributes are missing or have invalid values. |
| 55 | + :raises TypeError: If any of the attributes have invalid types. |
| 56 | + """ |
| 57 | + self._validate_attribute(attributes=attributes) |
| 58 | + self._attributes: dict[str, Any] = attributes |
| 59 | + self._data: Optional[dict] = data |
| 60 | + |
| 61 | + @staticmethod |
| 62 | + def _validate_attribute(attributes: dict[str, Any]) -> None: |
| 63 | + """ |
| 64 | + Validates the attributes of the CloudEvent as per the CloudEvents specification. |
| 65 | +
|
| 66 | + See https://github.com/cloudevents/spec/blob/main/cloudevents/spec.md#required-attributes |
| 67 | + """ |
| 68 | + errors: dict[str, list[BaseCloudEventException]] = defaultdict(list) |
| 69 | + errors.update(CloudEvent._validate_required_attributes(attributes=attributes)) |
| 70 | + errors.update(CloudEvent._validate_optional_attributes(attributes=attributes)) |
| 71 | + errors.update(CloudEvent._validate_extension_attributes(attributes=attributes)) |
| 72 | + if errors: |
| 73 | + raise CloudEventValidationError(errors=errors) |
| 74 | + |
| 75 | + @staticmethod |
| 76 | + def _validate_required_attributes( |
| 77 | + attributes: dict[str, Any], |
| 78 | + ) -> dict[str, list[BaseCloudEventException]]: |
| 79 | + """ |
| 80 | + Validates the types of the required attributes. |
| 81 | +
|
| 82 | + :param attributes: The attributes of the CloudEvent instance. |
| 83 | + :return: A dictionary of validation error messages. |
| 84 | + """ |
| 85 | + errors = defaultdict(list) |
| 86 | + |
| 87 | + if "id" not in attributes: |
| 88 | + errors["id"].append(MissingRequiredAttributeError(attribute_name="id")) |
| 89 | + if attributes.get("id") is None: |
| 90 | + errors["id"].append( |
| 91 | + InvalidAttributeValueError( |
| 92 | + attribute_name="id", msg="Attribute 'id' must not be None" |
| 93 | + ) |
| 94 | + ) |
| 95 | + if not isinstance(attributes.get("id"), str): |
| 96 | + errors["id"].append( |
| 97 | + InvalidAttributeTypeError(attribute_name="id", expected_type=str) |
| 98 | + ) |
| 99 | + |
| 100 | + if "source" not in attributes: |
| 101 | + errors["source"].append( |
| 102 | + MissingRequiredAttributeError(attribute_name="source") |
| 103 | + ) |
| 104 | + if not isinstance(attributes.get("source"), str): |
| 105 | + errors["source"].append( |
| 106 | + InvalidAttributeTypeError(attribute_name="source", expected_type=str) |
| 107 | + ) |
| 108 | + |
| 109 | + if "type" not in attributes: |
| 110 | + errors["type"].append(MissingRequiredAttributeError(attribute_name="type")) |
| 111 | + if not isinstance(attributes.get("type"), str): |
| 112 | + errors["type"].append( |
| 113 | + InvalidAttributeTypeError(attribute_name="type", expected_type=str) |
| 114 | + ) |
| 115 | + |
| 116 | + if "specversion" not in attributes: |
| 117 | + errors["specversion"].append( |
| 118 | + MissingRequiredAttributeError(attribute_name="specversion") |
| 119 | + ) |
| 120 | + if not isinstance(attributes.get("specversion"), str): |
| 121 | + errors["specversion"].append( |
| 122 | + InvalidAttributeTypeError( |
| 123 | + attribute_name="specversion", expected_type=str |
| 124 | + ) |
| 125 | + ) |
| 126 | + if attributes.get("specversion") != "1.0": |
| 127 | + errors["specversion"].append( |
| 128 | + InvalidAttributeValueError( |
| 129 | + attribute_name="specversion", |
| 130 | + msg="Attribute 'specversion' must be '1.0'", |
| 131 | + ) |
| 132 | + ) |
| 133 | + return errors |
| 134 | + |
| 135 | + @staticmethod |
| 136 | + def _validate_optional_attributes( |
| 137 | + attributes: dict[str, Any], |
| 138 | + ) -> dict[str, list[BaseCloudEventException]]: |
| 139 | + """ |
| 140 | + Validates the types and values of the optional attributes. |
| 141 | +
|
| 142 | + :param attributes: The attributes of the CloudEvent instance. |
| 143 | + :return: A dictionary of validation error messages. |
| 144 | + """ |
| 145 | + errors = defaultdict(list) |
| 146 | + |
| 147 | + if "time" in attributes: |
| 148 | + if not isinstance(attributes["time"], datetime): |
| 149 | + errors["time"].append( |
| 150 | + InvalidAttributeTypeError( |
| 151 | + attribute_name="time", expected_type=datetime |
| 152 | + ) |
| 153 | + ) |
| 154 | + if hasattr(attributes["time"], "tzinfo") and not attributes["time"].tzinfo: |
| 155 | + errors["time"].append( |
| 156 | + InvalidAttributeValueError( |
| 157 | + attribute_name="time", |
| 158 | + msg="Attribute 'time' must be timezone aware", |
| 159 | + ) |
| 160 | + ) |
| 161 | + if "subject" in attributes: |
| 162 | + if not isinstance(attributes["subject"], str): |
| 163 | + errors["subject"].append( |
| 164 | + InvalidAttributeTypeError( |
| 165 | + attribute_name="subject", expected_type=str |
| 166 | + ) |
| 167 | + ) |
| 168 | + if not attributes["subject"]: |
| 169 | + errors["subject"].append( |
| 170 | + InvalidAttributeValueError( |
| 171 | + attribute_name="subject", |
| 172 | + msg="Attribute 'subject' must not be empty", |
| 173 | + ) |
| 174 | + ) |
| 175 | + if "datacontenttype" in attributes: |
| 176 | + if not isinstance(attributes["datacontenttype"], str): |
| 177 | + errors["datacontenttype"].append( |
| 178 | + InvalidAttributeTypeError( |
| 179 | + attribute_name="datacontenttype", expected_type=str |
| 180 | + ) |
| 181 | + ) |
| 182 | + if not attributes["datacontenttype"]: |
| 183 | + errors["datacontenttype"].append( |
| 184 | + InvalidAttributeValueError( |
| 185 | + attribute_name="datacontenttype", |
| 186 | + msg="Attribute 'datacontenttype' must not be empty", |
| 187 | + ) |
| 188 | + ) |
| 189 | + if "dataschema" in attributes: |
| 190 | + if not isinstance(attributes["dataschema"], str): |
| 191 | + errors["dataschema"].append( |
| 192 | + InvalidAttributeTypeError( |
| 193 | + attribute_name="dataschema", expected_type=str |
| 194 | + ) |
| 195 | + ) |
| 196 | + if not attributes["dataschema"]: |
| 197 | + errors["dataschema"].append( |
| 198 | + InvalidAttributeValueError( |
| 199 | + attribute_name="dataschema", |
| 200 | + msg="Attribute 'dataschema' must not be empty", |
| 201 | + ) |
| 202 | + ) |
| 203 | + return errors |
| 204 | + |
| 205 | + @staticmethod |
| 206 | + def _validate_extension_attributes( |
| 207 | + attributes: dict[str, Any], |
| 208 | + ) -> dict[str, list[BaseCloudEventException]]: |
| 209 | + """ |
| 210 | + Validates the extension attributes. |
| 211 | +
|
| 212 | + :param attributes: The attributes of the CloudEvent instance. |
| 213 | + :return: A dictionary of validation error messages. |
| 214 | + """ |
| 215 | + errors = defaultdict(list) |
| 216 | + extension_attributes = [ |
| 217 | + key |
| 218 | + for key in attributes.keys() |
| 219 | + if key not in REQUIRED_ATTRIBUTES and key not in OPTIONAL_ATTRIBUTES |
| 220 | + ] |
| 221 | + for extension_attribute in extension_attributes: |
| 222 | + if extension_attribute == "data": |
| 223 | + errors[extension_attribute].append( |
| 224 | + CustomExtensionAttributeError( |
| 225 | + attribute_name=extension_attribute, |
| 226 | + msg="Extension attribute 'data' is reserved and must not be used", |
| 227 | + ) |
| 228 | + ) |
| 229 | + if not (1 <= len(extension_attribute) <= 20): |
| 230 | + errors[extension_attribute].append( |
| 231 | + CustomExtensionAttributeError( |
| 232 | + attribute_name=extension_attribute, |
| 233 | + msg=f"Extension attribute '{extension_attribute}' should be between 1 and 20 characters long", |
| 234 | + ) |
| 235 | + ) |
| 236 | + if not re.match(r"^[a-z0-9]+$", extension_attribute): |
| 237 | + errors[extension_attribute].append( |
| 238 | + CustomExtensionAttributeError( |
| 239 | + attribute_name=extension_attribute, |
| 240 | + msg=f"Extension attribute '{extension_attribute}' should only contain lowercase letters and numbers", |
| 241 | + ) |
| 242 | + ) |
| 243 | + return errors |
| 244 | + |
| 245 | + def get_id(self) -> str: |
| 246 | + """ |
| 247 | + Retrieve the ID of the event. |
| 248 | +
|
| 249 | + :return: The ID of the event. |
| 250 | + """ |
| 251 | + return self._attributes["id"] # type: ignore |
| 252 | + |
| 253 | + def get_source(self) -> str: |
| 254 | + """ |
| 255 | + Retrieve the source of the event. |
| 256 | +
|
| 257 | + :return: The source of the event. |
| 258 | + """ |
| 259 | + return self._attributes["source"] # type: ignore |
| 260 | + |
| 261 | + def get_type(self) -> str: |
| 262 | + """ |
| 263 | + Retrieve the type of the event. |
| 264 | +
|
| 265 | + :return: The type of the event. |
| 266 | + """ |
| 267 | + return self._attributes["type"] # type: ignore |
| 268 | + |
| 269 | + def get_specversion(self) -> str: |
| 270 | + """ |
| 271 | + Retrieve the specversion of the event. |
| 272 | +
|
| 273 | + :return: The specversion of the event. |
| 274 | + """ |
| 275 | + return self._attributes["specversion"] # type: ignore |
| 276 | + |
| 277 | + def get_datacontenttype(self) -> Optional[str]: |
| 278 | + """ |
| 279 | + Retrieve the datacontenttype of the event. |
| 280 | +
|
| 281 | + :return: The datacontenttype of the event. |
| 282 | + """ |
| 283 | + return self._attributes.get("datacontenttype") |
| 284 | + |
| 285 | + def get_dataschema(self) -> Optional[str]: |
| 286 | + """ |
| 287 | + Retrieve the dataschema of the event. |
| 288 | +
|
| 289 | + :return: The dataschema of the event. |
| 290 | + """ |
| 291 | + return self._attributes.get("dataschema") |
| 292 | + |
| 293 | + def get_subject(self) -> Optional[str]: |
| 294 | + """ |
| 295 | + Retrieve the subject of the event. |
| 296 | +
|
| 297 | + :return: The subject of the event. |
| 298 | + """ |
| 299 | + return self._attributes.get("subject") |
| 300 | + |
| 301 | + def get_time(self) -> Optional[datetime]: |
| 302 | + """ |
| 303 | + Retrieve the time of the event. |
| 304 | +
|
| 305 | + :return: The time of the event. |
| 306 | + """ |
| 307 | + return self._attributes.get("time") |
| 308 | + |
| 309 | + def get_extension(self, extension_name: str) -> Any: |
| 310 | + """ |
| 311 | + Retrieve an extension attribute of the event. |
| 312 | +
|
| 313 | + :param extension_name: The name of the extension attribute. |
| 314 | + :return: The value of the extension attribute. |
| 315 | + """ |
| 316 | + return self._attributes.get(extension_name) |
| 317 | + |
| 318 | + def get_data(self) -> Optional[dict]: |
| 319 | + """ |
| 320 | + Retrieve data of the event. |
| 321 | +
|
| 322 | + :return: The data of the event. |
| 323 | + """ |
| 324 | + return self._data |
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