Adafruit_CircuitPython_HTTP.../adafruit_httpserver/route.py
2023-07-13 10:25:38 +00:00

163 lines
4.7 KiB
Python

# SPDX-FileCopyrightText: Copyright (c) 2022 Dan Halbert for Adafruit Industries
#
# SPDX-License-Identifier: MIT
"""
`adafruit_httpserver.route`
====================================================
* Author(s): Dan Halbert, Michał Pokusa
"""
try:
from typing import Callable, List, Set, Union, Tuple, TYPE_CHECKING
if TYPE_CHECKING:
from .response import Response
except ImportError:
pass
import re
from .methods import GET
class Route:
"""Route definition for different paths, see `adafruit_httpserver.server.Server.route`."""
def __init__(
self,
path: str = "",
methods: Union[str, Set[str]] = GET,
handler: Callable = None,
*,
append_slash: bool = False,
) -> None:
self._validate_path(path, append_slash)
self.parameters_names = [
name[1:-1] for name in re.compile(r"/[^<>]*/?").split(path) if name != ""
]
self.path = re.sub(r"<\w+>", r"([^/]+)", path).replace("....", r".+").replace(
"...", r"[^/]+"
) + ("/?" if append_slash else "")
self.methods = (
set(methods) if isinstance(methods, (set, list)) else set([methods])
)
self.handler = handler
@staticmethod
def _validate_path(path: str, append_slash: bool) -> None:
if not path.startswith("/"):
raise ValueError("Path must start with a slash.")
if "<>" in path:
raise ValueError("All URL parameters must be named.")
if path.endswith("/") and append_slash:
raise ValueError("Cannot use append_slash=True when path ends with /")
def match(self, other: "Route") -> Tuple[bool, List[str]]:
"""
Checks if the route matches the other route.
If the route contains parameters, it will check if the ``other`` route contains values for
them.
Returns tuple of a boolean and a list of strings. The boolean indicates if the routes match,
and the list contains the values of the url parameters from the ``other`` route.
Examples::
route = Route("/example", GET, True)
other1a = Route("/example", GET)
other1b = Route("/example/", GET)
route.matches(other1a) # True, []
route.matches(other1b) # True, []
other2 = Route("/other-example", GET)
route.matches(other2) # False, []
...
route = Route("/example/<parameter>", GET)
other1 = Route("/example/123", GET)
route.matches(other1) # True, ["123"]
other2 = Route("/other-example", GET)
route.matches(other2) # False, []
...
route1 = Route("/example/.../something", GET)
other1 = Route("/example/123/something", GET)
route1.matches(other1) # True, []
route2 = Route("/example/..../something", GET)
other2 = Route("/example/123/456/something", GET)
route2.matches(other2) # True, []
"""
if not other.methods.issubset(self.methods):
return False, {}
regex_match = re.match(f"^{self.path}$", other.path)
if regex_match is None:
return False, {}
return True, dict(zip(self.parameters_names, regex_match.groups()))
def __repr__(self) -> str:
path = repr(self.path)
methods = repr(self.methods)
return f"Route(path={path}, methods={methods})"
class _Routes:
"""A collection of routes and their corresponding handlers."""
def __init__(self) -> None:
self._routes: List[Route] = []
def add(self, route: Route):
"""Adds a route and its handler to the collection."""
self._routes.append(route)
def find_handler(self, route: Route) -> Union[Callable["...", "Response"], None]:
"""
Finds a handler for a given route.
If route used URL parameters, the handler will be wrapped to pass the parameters to the
handler.
Example::
@server.route("/example/<my_parameter>", GET)
def route_func(request, my_parameter):
...
request.path == "/example/123" # True
my_parameter == "123" # True
"""
found_route, _route = False, None
for _route in self._routes:
matches, keyword_parameters = _route.match(route)
if matches:
found_route = True
break
if not found_route:
return None
handler = _route.handler
def wrapped_handler(request):
return handler(request, **keyword_parameters)
return wrapped_handler
def __repr__(self) -> str:
return f"_Routes({repr(self._routes)})"