Adafruit_CircuitPython_HTTP.../adafruit_httpserver/headers.py
2025-05-16 16:11:43 +00:00

143 lines
4.4 KiB
Python

# SPDX-FileCopyrightText: Copyright (c) 2022 Michał Pokusa
#
# SPDX-License-Identifier: MIT
"""
`adafruit_httpserver.headers`
====================================================
* Author(s): Michał Pokusa
"""
try:
from typing import Dict, List, Union
except ImportError:
pass
from .interfaces import _IFieldStorage
class Headers(_IFieldStorage):
"""
A dict-like class for storing HTTP headers.
Allows access to headers using **case insensitive** names.
Does **not** implement all dict methods.
Examples::
headers = Headers("Content-Type: text/html\\r\\nContent-Length: 1024\\r\\n")
# or
headers = Headers({"Content-Type": "text/html", "Content-Length": "1024"})
len(headers)
# 2
headers.setdefault("Access-Control-Allow-Origin", "*")
headers["Access-Control-Allow-Origin"]
# '*'
headers["Content-Length"]
# '1024'
headers["content-type"]
# 'text/html'
headers["User-Agent"]
# KeyError: User-Agent
"CONTENT-TYPE" in headers
# True
"""
_storage: Dict[str, List[str]]
def __init__(self, headers: Union[str, Dict[str, str]] = None) -> None:
self._storage = {}
if isinstance(headers, str):
for header_line in headers.strip().splitlines():
name, value = header_line.split(": ", 1)
self.add(name, value)
else:
for key, value in (headers or {}).items():
self.add(key, value)
def add(self, field_name: str, value: str):
"""
Adds a header with the given field name and value.
Allows adding multiple headers with the same name.
"""
self._add_field_value(field_name.lower(), value)
def get(self, field_name: str, default: str = None) -> Union[str, None]:
"""Returns the value for the given header name, or default if not found."""
return super().get(field_name.lower(), default)
def get_list(self, field_name: str) -> List[str]:
"""Get the list of values of a field."""
return super().get_list(field_name.lower())
def get_directive(self, name: str, default: str = None) -> Union[str, None]:
"""
Returns the main value (directive) for the given header name, or default if not found.
Example::
headers = Headers({"Content-Type": "text/html; charset=utf-8"})
headers.get_directive("Content-Type")
# 'text/html'
"""
header_value = self.get(name)
if header_value is None:
return default
return header_value.split(";")[0].strip('" ')
def get_parameter(self, name: str, parameter: str, default: str = None) -> Union[str, None]:
"""
Returns the value of the given parameter for the given header name, or default if not found.
Example::
headers = Headers({"Content-Type": "text/html; charset=utf-8"})
headers.get_parameter("Content-Type", "charset")
# 'utf-8'
"""
header_value = self.get(name)
if header_value is None:
return default
for header_parameter in header_value.split(";"):
if header_parameter.strip().startswith(parameter):
return header_parameter.strip().split("=")[1].strip('" ')
return default
def set(self, name: str, value: str):
"""Sets the value for the given header name."""
self._storage[name.lower()] = [value]
def setdefault(self, name: str, default: str = None):
"""Sets the value for the given header name if it does not exist."""
return self._storage.setdefault(name.lower(), [default])
def update(self, headers: Dict[str, str]):
"""Updates the headers with the given dict."""
return self._storage.update({key.lower(): [value] for key, value in headers.items()})
def copy(self):
"""Returns a copy of the headers."""
return Headers(
"\r\n".join(f"{key}: {value}" for key in self.fields for value in self.get_list(key))
)
def __getitem__(self, name: str):
return super().__getitem__(name.lower())
def __setitem__(self, name: str, value: str):
self._storage[name.lower()] = [value]
def __delitem__(self, name: str):
del self._storage[name.lower()]
def __contains__(self, key: str):
return super().__contains__(key.lower())