"""When it comes to combining multiple controller or view functions (however you want to call them) you need a dispatcher. A simple way would be applying regular expression tests on the ``PATH_INFO`` and calling registered callback functions that return the value then. This module implements a much more powerful system than simple regular expression matching because it can also convert values in the URLs and build URLs. Here a simple example that creates a URL map for an application with two subdomains (www and kb) and some URL rules: .. code-block:: python m = Map([ # Static URLs Rule('/', endpoint='static/index'), Rule('/about', endpoint='static/about'), Rule('/help', endpoint='static/help'), # Knowledge Base Subdomain('kb', [ Rule('/', endpoint='kb/index'), Rule('/browse/', endpoint='kb/browse'), Rule('/browse//', endpoint='kb/browse'), Rule('/browse//', endpoint='kb/browse') ]) ], default_subdomain='www') If the application doesn't use subdomains it's perfectly fine to not set the default subdomain and not use the `Subdomain` rule factory. The endpoint in the rules can be anything, for example import paths or unique identifiers. The WSGI application can use those endpoints to get the handler for that URL. It doesn't have to be a string at all but it's recommended. Now it's possible to create a URL adapter for one of the subdomains and build URLs: .. code-block:: python c = m.bind('example.com') c.build("kb/browse", dict(id=42)) 'http://kb.example.com/browse/42/' c.build("kb/browse", dict()) 'http://kb.example.com/browse/' c.build("kb/browse", dict(id=42, page=3)) 'http://kb.example.com/browse/42/3' c.build("static/about") '/about' c.build("static/index", force_external=True) 'http://www.example.com/' c = m.bind('example.com', subdomain='kb') c.build("static/about") 'http://www.example.com/about' The first argument to bind is the server name *without* the subdomain. Per default it will assume that the script is mounted on the root, but often that's not the case so you can provide the real mount point as second argument: .. code-block:: python c = m.bind('example.com', '/applications/example') The third argument can be the subdomain, if not given the default subdomain is used. For more details about binding have a look at the documentation of the `MapAdapter`. And here is how you can match URLs: .. code-block:: python c = m.bind('example.com') c.match("/") ('static/index', {}) c.match("/about") ('static/about', {}) c = m.bind('example.com', '/', 'kb') c.match("/") ('kb/index', {}) c.match("/browse/42/23") ('kb/browse', {'id': 42, 'page': 23}) If matching fails you get a ``NotFound`` exception, if the rule thinks it's a good idea to redirect (for example because the URL was defined to have a slash at the end but the request was missing that slash) it will raise a ``RequestRedirect`` exception. Both are subclasses of ``HTTPException`` so you can use those errors as responses in the application. If matching succeeded but the URL rule was incompatible to the given method (for example there were only rules for ``GET`` and ``HEAD`` but routing tried to match a ``POST`` request) a ``MethodNotAllowed`` exception is raised. """ import ast import difflib import posixpath import re import typing import typing as t import uuid import warnings from pprint import pformat from string import Template from threading import Lock from types import CodeType from ._internal import _encode_idna from ._internal import _get_environ from ._internal import _to_bytes from ._internal import _to_str from ._internal import _wsgi_decoding_dance from .datastructures import ImmutableDict from .datastructures import MultiDict from .exceptions import BadHost from .exceptions import BadRequest from .exceptions import HTTPException from .exceptions import MethodNotAllowed from .exceptions import NotFound from .urls import _fast_url_quote from .urls import url_encode from .urls import url_join from .urls import url_quote from .urls import url_unquote from .utils import cached_property from .utils import redirect from .wsgi import get_host if t.TYPE_CHECKING: import typing_extensions as te from _typeshed.wsgi import WSGIApplication from _typeshed.wsgi import WSGIEnvironment from .wrappers.request import Request from .wrappers.response import Response _rule_re = re.compile( r""" (?P[^<]*) # static rule data < (?: (?P[a-zA-Z_][a-zA-Z0-9_]*) # converter name (?:\((?P.*?)\))? # converter arguments \: # variable delimiter )? (?P[a-zA-Z_][a-zA-Z0-9_]*) # variable name > """, re.VERBOSE, ) _simple_rule_re = re.compile(r"<([^>]+)>") _converter_args_re = re.compile( r""" ((?P\w+)\s*=\s*)? (?P True|False| \d+.\d+| \d+.| \d+| [\w\d_.]+| [urUR]?(?P"[^"]*?"|'[^']*') )\s*, """, re.VERBOSE, ) _PYTHON_CONSTANTS = {"None": None, "True": True, "False": False} def _pythonize(value: str) -> t.Union[None, bool, int, float, str]: if value in _PYTHON_CONSTANTS: return _PYTHON_CONSTANTS[value] for convert in int, float: try: return convert(value) # type: ignore except ValueError: pass if value[:1] == value[-1:] and value[0] in "\"'": value = value[1:-1] return str(value) def parse_converter_args(argstr: str) -> t.Tuple[t.Tuple, t.Dict[str, t.Any]]: argstr += "," args = [] kwargs = {} for item in _converter_args_re.finditer(argstr): value = item.group("stringval") if value is None: value = item.group("value") value = _pythonize(value) if not item.group("name"): args.append(value) else: name = item.group("name") kwargs[name] = value return tuple(args), kwargs def parse_rule(rule: str) -> t.Iterator[t.Tuple[t.Optional[str], t.Optional[str], str]]: """Parse a rule and return it as generator. Each iteration yields tuples in the form ``(converter, arguments, variable)``. If the converter is `None` it's a static url part, otherwise it's a dynamic one. :internal: """ pos = 0 end = len(rule) do_match = _rule_re.match used_names = set() while pos < end: m = do_match(rule, pos) if m is None: break data = m.groupdict() if data["static"]: yield None, None, data["static"] variable = data["variable"] converter = data["converter"] or "default" if variable in used_names: raise ValueError(f"variable name {variable!r} used twice.") used_names.add(variable) yield converter, data["args"] or None, variable pos = m.end() if pos < end: remaining = rule[pos:] if ">" in remaining or "<" in remaining: raise ValueError(f"malformed url rule: {rule!r}") yield None, None, remaining class RoutingException(Exception): """Special exceptions that require the application to redirect, notifying about missing urls, etc. :internal: """ class RequestRedirect(HTTPException, RoutingException): """Raise if the map requests a redirect. This is for example the case if `strict_slashes` are activated and an url that requires a trailing slash. The attribute `new_url` contains the absolute destination url. """ code = 308 def __init__(self, new_url: str) -> None: super().__init__(new_url) self.new_url = new_url def get_response( self, environ: t.Optional[t.Union["WSGIEnvironment", "Request"]] = None, scope: t.Optional[dict] = None, ) -> "Response": return redirect(self.new_url, self.code) class RequestPath(RoutingException): """Internal exception.""" __slots__ = ("path_info",) def __init__(self, path_info: str) -> None: super().__init__() self.path_info = path_info class RequestAliasRedirect(RoutingException): # noqa: B903 """This rule is an alias and wants to redirect to the canonical URL.""" def __init__(self, matched_values: t.Mapping[str, t.Any]) -> None: super().__init__() self.matched_values = matched_values class BuildError(RoutingException, LookupError): """Raised if the build system cannot find a URL for an endpoint with the values provided. """ def __init__( self, endpoint: str, values: t.Mapping[str, t.Any], method: t.Optional[str], adapter: t.Optional["MapAdapter"] = None, ) -> None: super().__init__(endpoint, values, method) self.endpoint = endpoint self.values = values self.method = method self.adapter = adapter @cached_property def suggested(self) -> t.Optional["Rule"]: return self.closest_rule(self.adapter) def closest_rule(self, adapter: t.Optional["MapAdapter"]) -> t.Optional["Rule"]: def _score_rule(rule: "Rule") -> float: return sum( [ 0.98 * difflib.SequenceMatcher( None, rule.endpoint, self.endpoint ).ratio(), 0.01 * bool(set(self.values or ()).issubset(rule.arguments)), 0.01 * bool(rule.methods and self.method in rule.methods), ] ) if adapter and adapter.map._rules: return max(adapter.map._rules, key=_score_rule) return None def __str__(self) -> str: message = [f"Could not build url for endpoint {self.endpoint!r}"] if self.method: message.append(f" ({self.method!r})") if self.values: message.append(f" with values {sorted(self.values)!r}") message.append(".") if self.suggested: if self.endpoint == self.suggested.endpoint: if ( self.method and self.suggested.methods is not None and self.method not in self.suggested.methods ): message.append( " Did you mean to use methods" f" {sorted(self.suggested.methods)!r}?" ) missing_values = self.suggested.arguments.union( set(self.suggested.defaults or ()) ) - set(self.values.keys()) if missing_values: message.append( f" Did you forget to specify values {sorted(missing_values)!r}?" ) else: message.append(f" Did you mean {self.suggested.endpoint!r} instead?") return "".join(message) class WebsocketMismatch(BadRequest): """The only matched rule is either a WebSocket and the request is HTTP, or the rule is HTTP and the request is a WebSocket. """ class ValidationError(ValueError): """Validation error. If a rule converter raises this exception the rule does not match the current URL and the next URL is tried. """ class RuleFactory: """As soon as you have more complex URL setups it's a good idea to use rule factories to avoid repetitive tasks. Some of them are builtin, others can be added by subclassing `RuleFactory` and overriding `get_rules`. """ def get_rules(self, map: "Map") -> t.Iterable["Rule"]: """Subclasses of `RuleFactory` have to override this method and return an iterable of rules.""" raise NotImplementedError() class Subdomain(RuleFactory): """All URLs provided by this factory have the subdomain set to a specific domain. For example if you want to use the subdomain for the current language this can be a good setup:: url_map = Map([ Rule('/', endpoint='#select_language'), Subdomain('', [ Rule('/', endpoint='index'), Rule('/about', endpoint='about'), Rule('/help', endpoint='help') ]) ]) All the rules except for the ``'#select_language'`` endpoint will now listen on a two letter long subdomain that holds the language code for the current request. """ def __init__(self, subdomain: str, rules: t.Iterable[RuleFactory]) -> None: self.subdomain = subdomain self.rules = rules def get_rules(self, map: "Map") -> t.Iterator["Rule"]: for rulefactory in self.rules: for rule in rulefactory.get_rules(map): rule = rule.empty() rule.subdomain = self.subdomain yield rule class Submount(RuleFactory): """Like `Subdomain` but prefixes the URL rule with a given string:: url_map = Map([ Rule('/', endpoint='index'), Submount('/blog', [ Rule('/', endpoint='blog/index'), Rule('/entry/', endpoint='blog/show') ]) ]) Now the rule ``'blog/show'`` matches ``/blog/entry/``. """ def __init__(self, path: str, rules: t.Iterable[RuleFactory]) -> None: self.path = path.rstrip("/") self.rules = rules def get_rules(self, map: "Map") -> t.Iterator["Rule"]: for rulefactory in self.rules: for rule in rulefactory.get_rules(map): rule = rule.empty() rule.rule = self.path + rule.rule yield rule class EndpointPrefix(RuleFactory): """Prefixes all endpoints (which must be strings for this factory) with another string. This can be useful for sub applications:: url_map = Map([ Rule('/', endpoint='index'), EndpointPrefix('blog/', [Submount('/blog', [ Rule('/', endpoint='index'), Rule('/entry/', endpoint='show') ])]) ]) """ def __init__(self, prefix: str, rules: t.Iterable[RuleFactory]) -> None: self.prefix = prefix self.rules = rules def get_rules(self, map: "Map") -> t.Iterator["Rule"]: for rulefactory in self.rules: for rule in rulefactory.get_rules(map): rule = rule.empty() rule.endpoint = self.prefix + rule.endpoint yield rule class RuleTemplate: """Returns copies of the rules wrapped and expands string templates in the endpoint, rule, defaults or subdomain sections. Here a small example for such a rule template:: from werkzeug.routing import Map, Rule, RuleTemplate resource = RuleTemplate([ Rule('/$name/', endpoint='$name.list'), Rule('/$name/', endpoint='$name.show') ]) url_map = Map([resource(name='user'), resource(name='page')]) When a rule template is called the keyword arguments are used to replace the placeholders in all the string parameters. """ def __init__(self, rules: t.Iterable["Rule"]) -> None: self.rules = list(rules) def __call__(self, *args: t.Any, **kwargs: t.Any) -> "RuleTemplateFactory": return RuleTemplateFactory(self.rules, dict(*args, **kwargs)) class RuleTemplateFactory(RuleFactory): """A factory that fills in template variables into rules. Used by `RuleTemplate` internally. :internal: """ def __init__( self, rules: t.Iterable[RuleFactory], context: t.Dict[str, t.Any] ) -> None: self.rules = rules self.context = context def get_rules(self, map: "Map") -> t.Iterator["Rule"]: for rulefactory in self.rules: for rule in rulefactory.get_rules(map): new_defaults = subdomain = None if rule.defaults: new_defaults = {} for key, value in rule.defaults.items(): if isinstance(value, str): value = Template(value).substitute(self.context) new_defaults[key] = value if rule.subdomain is not None: subdomain = Template(rule.subdomain).substitute(self.context) new_endpoint = rule.endpoint if isinstance(new_endpoint, str): new_endpoint = Template(new_endpoint).substitute(self.context) yield Rule( Template(rule.rule).substitute(self.context), new_defaults, subdomain, rule.methods, rule.build_only, new_endpoint, rule.strict_slashes, ) def _prefix_names(src: str) -> ast.stmt: """ast parse and prefix names with `.` to avoid collision with user vars""" tree = ast.parse(src).body[0] if isinstance(tree, ast.Expr): tree = tree.value # type: ignore for node in ast.walk(tree): if isinstance(node, ast.Name): node.id = f".{node.id}" return tree _CALL_CONVERTER_CODE_FMT = "self._converters[{elem!r}].to_url()" _IF_KWARGS_URL_ENCODE_CODE = """\ if kwargs: q = '?' params = self._encode_query_vars(kwargs) else: q = params = '' """ _IF_KWARGS_URL_ENCODE_AST = _prefix_names(_IF_KWARGS_URL_ENCODE_CODE) _URL_ENCODE_AST_NAMES = (_prefix_names("q"), _prefix_names("params")) class Rule(RuleFactory): """A Rule represents one URL pattern. There are some options for `Rule` that change the way it behaves and are passed to the `Rule` constructor. Note that besides the rule-string all arguments *must* be keyword arguments in order to not break the application on Werkzeug upgrades. `string` Rule strings basically are just normal URL paths with placeholders in the format ```` where the converter and the arguments are optional. If no converter is defined the `default` converter is used which means `string` in the normal configuration. URL rules that end with a slash are branch URLs, others are leaves. If you have `strict_slashes` enabled (which is the default), all branch URLs that are matched without a trailing slash will trigger a redirect to the same URL with the missing slash appended. The converters are defined on the `Map`. `endpoint` The endpoint for this rule. This can be anything. A reference to a function, a string, a number etc. The preferred way is using a string because the endpoint is used for URL generation. `defaults` An optional dict with defaults for other rules with the same endpoint. This is a bit tricky but useful if you want to have unique URLs:: url_map = Map([ Rule('/all/', defaults={'page': 1}, endpoint='all_entries'), Rule('/all/page/', endpoint='all_entries') ]) If a user now visits ``http://example.com/all/page/1`` he will be redirected to ``http://example.com/all/``. If `redirect_defaults` is disabled on the `Map` instance this will only affect the URL generation. `subdomain` The subdomain rule string for this rule. If not specified the rule only matches for the `default_subdomain` of the map. If the map is not bound to a subdomain this feature is disabled. Can be useful if you want to have user profiles on different subdomains and all subdomains are forwarded to your application:: url_map = Map([ Rule('/', subdomain='', endpoint='user/homepage'), Rule('/stats', subdomain='', endpoint='user/stats') ]) `methods` A sequence of http methods this rule applies to. If not specified, all methods are allowed. For example this can be useful if you want different endpoints for `POST` and `GET`. If methods are defined and the path matches but the method matched against is not in this list or in the list of another rule for that path the error raised is of the type `MethodNotAllowed` rather than `NotFound`. If `GET` is present in the list of methods and `HEAD` is not, `HEAD` is added automatically. `strict_slashes` Override the `Map` setting for `strict_slashes` only for this rule. If not specified the `Map` setting is used. `merge_slashes` Override :attr:`Map.merge_slashes` for this rule. `build_only` Set this to True and the rule will never match but will create a URL that can be build. This is useful if you have resources on a subdomain or folder that are not handled by the WSGI application (like static data) `redirect_to` If given this must be either a string or callable. In case of a callable it's called with the url adapter that triggered the match and the values of the URL as keyword arguments and has to return the target for the redirect, otherwise it has to be a string with placeholders in rule syntax:: def foo_with_slug(adapter, id): # ask the database for the slug for the old id. this of # course has nothing to do with werkzeug. return f'foo/{Foo.get_slug_for_id(id)}' url_map = Map([ Rule('/foo/', endpoint='foo'), Rule('/some/old/url/', redirect_to='foo/'), Rule('/other/old/url/', redirect_to=foo_with_slug) ]) When the rule is matched the routing system will raise a `RequestRedirect` exception with the target for the redirect. Keep in mind that the URL will be joined against the URL root of the script so don't use a leading slash on the target URL unless you really mean root of that domain. `alias` If enabled this rule serves as an alias for another rule with the same endpoint and arguments. `host` If provided and the URL map has host matching enabled this can be used to provide a match rule for the whole host. This also means that the subdomain feature is disabled. `websocket` If ``True``, this rule is only matches for WebSocket (``ws://``, ``wss://``) requests. By default, rules will only match for HTTP requests. .. versionadded:: 1.0 Added ``websocket``. .. versionadded:: 1.0 Added ``merge_slashes``. .. versionadded:: 0.7 Added ``alias`` and ``host``. .. versionchanged:: 0.6.1 ``HEAD`` is added to ``methods`` if ``GET`` is present. """ def __init__( self, string: str, defaults: t.Optional[t.Mapping[str, t.Any]] = None, subdomain: t.Optional[str] = None, methods: t.Optional[t.Iterable[str]] = None, build_only: bool = False, endpoint: t.Optional[str] = None, strict_slashes: t.Optional[bool] = None, merge_slashes: t.Optional[bool] = None, redirect_to: t.Optional[t.Union[str, t.Callable[..., str]]] = None, alias: bool = False, host: t.Optional[str] = None, websocket: bool = False, ) -> None: if not string.startswith("/"): raise ValueError("urls must start with a leading slash") self.rule = string self.is_leaf = not string.endswith("/") self.map: "Map" = None # type: ignore self.strict_slashes = strict_slashes self.merge_slashes = merge_slashes self.subdomain = subdomain self.host = host self.defaults = defaults self.build_only = build_only self.alias = alias self.websocket = websocket if methods is not None: if isinstance(methods, str): raise TypeError("'methods' should be a list of strings.") methods = {x.upper() for x in methods} if "HEAD" not in methods and "GET" in methods: methods.add("HEAD") if websocket and methods - {"GET", "HEAD", "OPTIONS"}: raise ValueError( "WebSocket rules can only use 'GET', 'HEAD', and 'OPTIONS' methods." ) self.methods = methods self.endpoint: str = endpoint # type: ignore self.redirect_to = redirect_to if defaults: self.arguments = set(map(str, defaults)) else: self.arguments = set() self._trace: t.List[t.Tuple[bool, str]] = [] def empty(self) -> "Rule": """ Return an unbound copy of this rule. This can be useful if want to reuse an already bound URL for another map. See ``get_empty_kwargs`` to override what keyword arguments are provided to the new copy. """ return type(self)(self.rule, **self.get_empty_kwargs()) def get_empty_kwargs(self) -> t.Mapping[str, t.Any]: """ Provides kwargs for instantiating empty copy with empty() Use this method to provide custom keyword arguments to the subclass of ``Rule`` when calling ``some_rule.empty()``. Helpful when the subclass has custom keyword arguments that are needed at instantiation. Must return a ``dict`` that will be provided as kwargs to the new instance of ``Rule``, following the initial ``self.rule`` value which is always provided as the first, required positional argument. """ defaults = None if self.defaults: defaults = dict(self.defaults) return dict( defaults=defaults, subdomain=self.subdomain, methods=self.methods, build_only=self.build_only, endpoint=self.endpoint, strict_slashes=self.strict_slashes, redirect_to=self.redirect_to, alias=self.alias, host=self.host, ) def get_rules(self, map: "Map") -> t.Iterator["Rule"]: yield self def refresh(self) -> None: """Rebinds and refreshes the URL. Call this if you modified the rule in place. :internal: """ self.bind(self.map, rebind=True) def bind(self, map: "Map", rebind: bool = False) -> None: """Bind the url to a map and create a regular expression based on the information from the rule itself and the defaults from the map. :internal: """ if self.map is not None and not rebind: raise RuntimeError(f"url rule {self!r} already bound to map {self.map!r}") self.map = map if self.strict_slashes is None: self.strict_slashes = map.strict_slashes if self.merge_slashes is None: self.merge_slashes = map.merge_slashes if self.subdomain is None: self.subdomain = map.default_subdomain self.compile() def get_converter( self, variable_name: str, converter_name: str, args: t.Tuple, kwargs: t.Mapping[str, t.Any], ) -> "BaseConverter": """Looks up the converter for the given parameter. .. versionadded:: 0.9 """ if converter_name not in self.map.converters: raise LookupError(f"the converter {converter_name!r} does not exist") return self.map.converters[converter_name](self.map, *args, **kwargs) def _encode_query_vars(self, query_vars: t.Mapping[str, t.Any]) -> str: return url_encode( query_vars, charset=self.map.charset, sort=self.map.sort_parameters, key=self.map.sort_key, ) def compile(self) -> None: """Compiles the regular expression and stores it.""" assert self.map is not None, "rule not bound" if self.map.host_matching: domain_rule = self.host or "" else: domain_rule = self.subdomain or "" self._trace = [] self._converters: t.Dict[str, "BaseConverter"] = {} self._static_weights: t.List[t.Tuple[int, int]] = [] self._argument_weights: t.List[int] = [] regex_parts = [] def _build_regex(rule: str) -> None: index = 0 for converter, arguments, variable in parse_rule(rule): if converter is None: for match in re.finditer(r"/+|[^/]+", variable): part = match.group(0) if part.startswith("/"): if self.merge_slashes: regex_parts.append(r"/+?") self._trace.append((False, "/")) else: regex_parts.append(part) self._trace.append((False, part)) continue self._trace.append((False, part)) regex_parts.append(re.escape(part)) if part: self._static_weights.append((index, -len(part))) else: if arguments: c_args, c_kwargs = parse_converter_args(arguments) else: c_args = () c_kwargs = {} convobj = self.get_converter(variable, converter, c_args, c_kwargs) regex_parts.append(f"(?P<{variable}>{convobj.regex})") self._converters[variable] = convobj self._trace.append((True, variable)) self._argument_weights.append(convobj.weight) self.arguments.add(str(variable)) index = index + 1 _build_regex(domain_rule) regex_parts.append("\\|") self._trace.append((False, "|")) _build_regex(self.rule if self.is_leaf else self.rule.rstrip("/")) if not self.is_leaf: self._trace.append((False, "/")) self._build: t.Callable[..., t.Tuple[str, str]] self._build = self._compile_builder(False).__get__(self, None) # type: ignore self._build_unknown: t.Callable[..., t.Tuple[str, str]] self._build_unknown = self._compile_builder(True).__get__( # type: ignore self, None ) if self.build_only: return if not (self.is_leaf and self.strict_slashes): reps = "*" if self.merge_slashes else "?" tail = f"(?/{reps})" else: tail = "" regex = f"^{''.join(regex_parts)}{tail}$" self._regex = re.compile(regex) def match( self, path: str, method: t.Optional[str] = None ) -> t.Optional[t.MutableMapping[str, t.Any]]: """Check if the rule matches a given path. Path is a string in the form ``"subdomain|/path"`` and is assembled by the map. If the map is doing host matching the subdomain part will be the host instead. If the rule matches a dict with the converted values is returned, otherwise the return value is `None`. :internal: """ if not self.build_only: require_redirect = False m = self._regex.search(path) if m is not None: groups = m.groupdict() # we have a folder like part of the url without a trailing # slash and strict slashes enabled. raise an exception that # tells the map to redirect to the same url but with a # trailing slash if ( self.strict_slashes and not self.is_leaf and not groups.pop("__suffix__") and ( method is None or self.methods is None or method in self.methods ) ): path += "/" require_redirect = True # if we are not in strict slashes mode we have to remove # a __suffix__ elif not self.strict_slashes: del groups["__suffix__"] result = {} for name, value in groups.items(): try: value = self._converters[name].to_python(value) except ValidationError: return None result[str(name)] = value if self.defaults: result.update(self.defaults) if self.merge_slashes: new_path = "|".join(self.build(result, False)) # type: ignore if path.endswith("/") and not new_path.endswith("/"): new_path += "/" if new_path.count("/") < path.count("/"): # The URL will be encoded when MapAdapter.match # handles the RequestPath raised below. Decode # the URL here to avoid a double encoding. path = url_unquote(new_path) require_redirect = True if require_redirect: path = path.split("|", 1)[1] raise RequestPath(path) if self.alias and self.map.redirect_defaults: raise RequestAliasRedirect(result) return result return None @staticmethod def _get_func_code(code: CodeType, name: str) -> t.Callable[..., t.Tuple[str, str]]: globs: t.Dict[str, t.Any] = {} locs: t.Dict[str, t.Any] = {} exec(code, globs, locs) return locs[name] # type: ignore def _compile_builder( self, append_unknown: bool = True ) -> t.Callable[..., t.Tuple[str, str]]: defaults = self.defaults or {} dom_ops: t.List[t.Tuple[bool, str]] = [] url_ops: t.List[t.Tuple[bool, str]] = [] opl = dom_ops for is_dynamic, data in self._trace: if data == "|" and opl is dom_ops: opl = url_ops continue # this seems like a silly case to ever come up but: # if a default is given for a value that appears in the rule, # resolve it to a constant ahead of time if is_dynamic and data in defaults: data = self._converters[data].to_url(defaults[data]) opl.append((False, data)) elif not is_dynamic: opl.append( (False, url_quote(_to_bytes(data, self.map.charset), safe="/:|+")) ) else: opl.append((True, data)) def _convert(elem: str) -> ast.stmt: ret = _prefix_names(_CALL_CONVERTER_CODE_FMT.format(elem=elem)) ret.args = [ast.Name(str(elem), ast.Load())] # type: ignore # str for py2 return ret def _parts(ops: t.List[t.Tuple[bool, str]]) -> t.List[ast.AST]: parts = [ _convert(elem) if is_dynamic else ast.Str(s=elem) for is_dynamic, elem in ops ] parts = parts or [ast.Str("")] # constant fold ret = [parts[0]] for p in parts[1:]: if isinstance(p, ast.Str) and isinstance(ret[-1], ast.Str): ret[-1] = ast.Str(ret[-1].s + p.s) else: ret.append(p) return ret dom_parts = _parts(dom_ops) url_parts = _parts(url_ops) if not append_unknown: body = [] else: body = [_IF_KWARGS_URL_ENCODE_AST] url_parts.extend(_URL_ENCODE_AST_NAMES) def _join(parts: t.List[ast.AST]) -> ast.AST: if len(parts) == 1: # shortcut return parts[0] return ast.JoinedStr(parts) body.append( ast.Return(ast.Tuple([_join(dom_parts), _join(url_parts)], ast.Load())) ) pargs = [ elem for is_dynamic, elem in dom_ops + url_ops if is_dynamic and elem not in defaults ] kargs = [str(k) for k in defaults] func_ast: ast.FunctionDef = _prefix_names("def _(): pass") # type: ignore func_ast.name = f"" func_ast.args.args.append(ast.arg(".self", None)) for arg in pargs + kargs: func_ast.args.args.append(ast.arg(arg, None)) func_ast.args.kwarg = ast.arg(".kwargs", None) for _ in kargs: func_ast.args.defaults.append(ast.Str("")) func_ast.body = body # use `ast.parse` instead of `ast.Module` for better portability # Python 3.8 changes the signature of `ast.Module` module = ast.parse("") module.body = [func_ast] # mark everything as on line 1, offset 0 # less error-prone than `ast.fix_missing_locations` # bad line numbers cause an assert to fail in debug builds for node in ast.walk(module): if "lineno" in node._attributes: node.lineno = 1 if "col_offset" in node._attributes: node.col_offset = 0 code = compile(module, "", "exec") return self._get_func_code(code, func_ast.name) def build( self, values: t.Mapping[str, t.Any], append_unknown: bool = True ) -> t.Optional[t.Tuple[str, str]]: """Assembles the relative url for that rule and the subdomain. If building doesn't work for some reasons `None` is returned. :internal: """ try: if append_unknown: return self._build_unknown(**values) else: return self._build(**values) except ValidationError: return None def provides_defaults_for(self, rule: "Rule") -> bool: """Check if this rule has defaults for a given rule. :internal: """ return bool( not self.build_only and self.defaults and self.endpoint == rule.endpoint and self != rule and self.arguments == rule.arguments ) def suitable_for( self, values: t.Mapping[str, t.Any], method: t.Optional[str] = None ) -> bool: """Check if the dict of values has enough data for url generation. :internal: """ # if a method was given explicitly and that method is not supported # by this rule, this rule is not suitable. if ( method is not None and self.methods is not None and method not in self.methods ): return False defaults = self.defaults or () # all arguments required must be either in the defaults dict or # the value dictionary otherwise it's not suitable for key in self.arguments: if key not in defaults and key not in values: return False # in case defaults are given we ensure that either the value was # skipped or the value is the same as the default value. if defaults: for key, value in defaults.items(): if key in values and value != values[key]: return False return True def match_compare_key( self, ) -> t.Tuple[bool, int, t.Iterable[t.Tuple[int, int]], int, t.Iterable[int]]: """The match compare key for sorting. Current implementation: 1. rules without any arguments come first for performance reasons only as we expect them to match faster and some common ones usually don't have any arguments (index pages etc.) 2. rules with more static parts come first so the second argument is the negative length of the number of the static weights. 3. we order by static weights, which is a combination of index and length 4. The more complex rules come first so the next argument is the negative length of the number of argument weights. 5. lastly we order by the actual argument weights. :internal: """ return ( bool(self.arguments), -len(self._static_weights), self._static_weights, -len(self._argument_weights), self._argument_weights, ) def build_compare_key(self) -> t.Tuple[int, int, int]: """The build compare key for sorting. :internal: """ return (1 if self.alias else 0, -len(self.arguments), -len(self.defaults or ())) def __eq__(self, other: object) -> bool: return isinstance(other, type(self)) and self._trace == other._trace __hash__ = None # type: ignore def __str__(self) -> str: return self.rule def __repr__(self) -> str: if self.map is None: return f"<{type(self).__name__} (unbound)>" parts = [] for is_dynamic, data in self._trace: if is_dynamic: parts.append(f"<{data}>") else: parts.append(data) parts = "".join(parts).lstrip("|") methods = f" ({', '.join(self.methods)})" if self.methods is not None else "" return f"<{type(self).__name__} {parts!r}{methods} -> {self.endpoint}>" class BaseConverter: """Base class for all converters.""" regex = "[^/]+" weight = 100 def __init__(self, map: "Map", *args: t.Any, **kwargs: t.Any) -> None: self.map = map def to_python(self, value: str) -> t.Any: return value def to_url(self, value: t.Any) -> str: if isinstance(value, (bytes, bytearray)): return _fast_url_quote(value) return _fast_url_quote(str(value).encode(self.map.charset)) class UnicodeConverter(BaseConverter): """This converter is the default converter and accepts any string but only one path segment. Thus the string can not include a slash. This is the default validator. Example:: Rule('/pages/'), Rule('/') :param map: the :class:`Map`. :param minlength: the minimum length of the string. Must be greater or equal 1. :param maxlength: the maximum length of the string. :param length: the exact length of the string. """ def __init__( self, map: "Map", minlength: int = 1, maxlength: t.Optional[int] = None, length: t.Optional[int] = None, ) -> None: super().__init__(map) if length is not None: length_regex = f"{{{int(length)}}}" else: if maxlength is None: maxlength_value = "" else: maxlength_value = str(int(maxlength)) length_regex = f"{{{int(minlength)},{maxlength_value}}}" self.regex = f"[^/]{length_regex}" class AnyConverter(BaseConverter): """Matches one of the items provided. Items can either be Python identifiers or strings:: Rule('/') :param map: the :class:`Map`. :param items: this function accepts the possible items as positional arguments. """ def __init__(self, map: "Map", *items: str) -> None: super().__init__(map) self.regex = f"(?:{'|'.join([re.escape(x) for x in items])})" class PathConverter(BaseConverter): """Like the default :class:`UnicodeConverter`, but it also matches slashes. This is useful for wikis and similar applications:: Rule('/') Rule('//edit') :param map: the :class:`Map`. """ regex = "[^/].*?" weight = 200 class NumberConverter(BaseConverter): """Baseclass for `IntegerConverter` and `FloatConverter`. :internal: """ weight = 50 num_convert: t.Callable = int def __init__( self, map: "Map", fixed_digits: int = 0, min: t.Optional[int] = None, max: t.Optional[int] = None, signed: bool = False, ) -> None: if signed: self.regex = self.signed_regex super().__init__(map) self.fixed_digits = fixed_digits self.min = min self.max = max self.signed = signed def to_python(self, value: str) -> t.Any: if self.fixed_digits and len(value) != self.fixed_digits: raise ValidationError() value = self.num_convert(value) if (self.min is not None and value < self.min) or ( self.max is not None and value > self.max ): raise ValidationError() return value def to_url(self, value: t.Any) -> str: value = str(self.num_convert(value)) if self.fixed_digits: value = value.zfill(self.fixed_digits) return value @property def signed_regex(self) -> str: return f"-?{self.regex}" class IntegerConverter(NumberConverter): """This converter only accepts integer values:: Rule("/page/") By default it only accepts unsigned, positive values. The ``signed`` parameter will enable signed, negative values. :: Rule("/page/") :param map: The :class:`Map`. :param fixed_digits: The number of fixed digits in the URL. If you set this to ``4`` for example, the rule will only match if the URL looks like ``/0001/``. The default is variable length. :param min: The minimal value. :param max: The maximal value. :param signed: Allow signed (negative) values. .. versionadded:: 0.15 The ``signed`` parameter. """ regex = r"\d+" class FloatConverter(NumberConverter): """This converter only accepts floating point values:: Rule("/probability/") By default it only accepts unsigned, positive values. The ``signed`` parameter will enable signed, negative values. :: Rule("/offset/") :param map: The :class:`Map`. :param min: The minimal value. :param max: The maximal value. :param signed: Allow signed (negative) values. .. versionadded:: 0.15 The ``signed`` parameter. """ regex = r"\d+\.\d+" num_convert = float def __init__( self, map: "Map", min: t.Optional[float] = None, max: t.Optional[float] = None, signed: bool = False, ) -> None: super().__init__(map, min=min, max=max, signed=signed) # type: ignore class UUIDConverter(BaseConverter): """This converter only accepts UUID strings:: Rule('/object/') .. versionadded:: 0.10 :param map: the :class:`Map`. """ regex = ( r"[A-Fa-f0-9]{8}-[A-Fa-f0-9]{4}-" r"[A-Fa-f0-9]{4}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{12}" ) def to_python(self, value: str) -> uuid.UUID: return uuid.UUID(value) def to_url(self, value: uuid.UUID) -> str: return str(value) #: the default converter mapping for the map. DEFAULT_CONVERTERS: t.Mapping[str, t.Type[BaseConverter]] = { "default": UnicodeConverter, "string": UnicodeConverter, "any": AnyConverter, "path": PathConverter, "int": IntegerConverter, "float": FloatConverter, "uuid": UUIDConverter, } class Map: """The map class stores all the URL rules and some configuration parameters. Some of the configuration values are only stored on the `Map` instance since those affect all rules, others are just defaults and can be overridden for each rule. Note that you have to specify all arguments besides the `rules` as keyword arguments! :param rules: sequence of url rules for this map. :param default_subdomain: The default subdomain for rules without a subdomain defined. :param charset: charset of the url. defaults to ``"utf-8"`` :param strict_slashes: If a rule ends with a slash but the matched URL does not, redirect to the URL with a trailing slash. :param merge_slashes: Merge consecutive slashes when matching or building URLs. Matches will redirect to the normalized URL. Slashes in variable parts are not merged. :param redirect_defaults: This will redirect to the default rule if it wasn't visited that way. This helps creating unique URLs. :param converters: A dict of converters that adds additional converters to the list of converters. If you redefine one converter this will override the original one. :param sort_parameters: If set to `True` the url parameters are sorted. See `url_encode` for more details. :param sort_key: The sort key function for `url_encode`. :param encoding_errors: the error method to use for decoding :param host_matching: if set to `True` it enables the host matching feature and disables the subdomain one. If enabled the `host` parameter to rules is used instead of the `subdomain` one. .. versionchanged:: 1.0 If ``url_scheme`` is ``ws`` or ``wss``, only WebSocket rules will match. .. versionchanged:: 1.0 Added ``merge_slashes``. .. versionchanged:: 0.7 Added ``encoding_errors`` and ``host_matching``. .. versionchanged:: 0.5 Added ``sort_parameters`` and ``sort_key``. """ #: A dict of default converters to be used. default_converters = ImmutableDict(DEFAULT_CONVERTERS) #: The type of lock to use when updating. #: #: .. versionadded:: 1.0 lock_class = Lock def __init__( self, rules: t.Optional[t.Iterable[RuleFactory]] = None, default_subdomain: str = "", charset: str = "utf-8", strict_slashes: bool = True, merge_slashes: bool = True, redirect_defaults: bool = True, converters: t.Optional[t.Mapping[str, t.Type[BaseConverter]]] = None, sort_parameters: bool = False, sort_key: t.Optional[t.Callable[[t.Any], t.Any]] = None, encoding_errors: str = "replace", host_matching: bool = False, ) -> None: self._rules: t.List[Rule] = [] self._rules_by_endpoint: t.Dict[str, t.List[Rule]] = {} self._remap = True self._remap_lock = self.lock_class() self.default_subdomain = default_subdomain self.charset = charset self.encoding_errors = encoding_errors self.strict_slashes = strict_slashes self.merge_slashes = merge_slashes self.redirect_defaults = redirect_defaults self.host_matching = host_matching self.converters = self.default_converters.copy() if converters: self.converters.update(converters) self.sort_parameters = sort_parameters self.sort_key = sort_key for rulefactory in rules or (): self.add(rulefactory) def is_endpoint_expecting(self, endpoint: str, *arguments: str) -> bool: """Iterate over all rules and check if the endpoint expects the arguments provided. This is for example useful if you have some URLs that expect a language code and others that do not and you want to wrap the builder a bit so that the current language code is automatically added if not provided but endpoints expect it. :param endpoint: the endpoint to check. :param arguments: this function accepts one or more arguments as positional arguments. Each one of them is checked. """ self.update() arguments = set(arguments) for rule in self._rules_by_endpoint[endpoint]: if arguments.issubset(rule.arguments): return True return False def iter_rules(self, endpoint: t.Optional[str] = None) -> t.Iterator[Rule]: """Iterate over all rules or the rules of an endpoint. :param endpoint: if provided only the rules for that endpoint are returned. :return: an iterator """ self.update() if endpoint is not None: return iter(self._rules_by_endpoint[endpoint]) return iter(self._rules) def add(self, rulefactory: RuleFactory) -> None: """Add a new rule or factory to the map and bind it. Requires that the rule is not bound to another map. :param rulefactory: a :class:`Rule` or :class:`RuleFactory` """ for rule in rulefactory.get_rules(self): rule.bind(self) self._rules.append(rule) self._rules_by_endpoint.setdefault(rule.endpoint, []).append(rule) self._remap = True def bind( self, server_name: str, script_name: t.Optional[str] = None, subdomain: t.Optional[str] = None, url_scheme: str = "http", default_method: str = "GET", path_info: t.Optional[str] = None, query_args: t.Optional[t.Union[t.Mapping[str, t.Any], str]] = None, ) -> "MapAdapter": """Return a new :class:`MapAdapter` with the details specified to the call. Note that `script_name` will default to ``'/'`` if not further specified or `None`. The `server_name` at least is a requirement because the HTTP RFC requires absolute URLs for redirects and so all redirect exceptions raised by Werkzeug will contain the full canonical URL. If no path_info is passed to :meth:`match` it will use the default path info passed to bind. While this doesn't really make sense for manual bind calls, it's useful if you bind a map to a WSGI environment which already contains the path info. `subdomain` will default to the `default_subdomain` for this map if no defined. If there is no `default_subdomain` you cannot use the subdomain feature. .. versionchanged:: 1.0 If ``url_scheme`` is ``ws`` or ``wss``, only WebSocket rules will match. .. versionchanged:: 0.15 ``path_info`` defaults to ``'/'`` if ``None``. .. versionchanged:: 0.8 ``query_args`` can be a string. .. versionchanged:: 0.7 Added ``query_args``. """ server_name = server_name.lower() if self.host_matching: if subdomain is not None: raise RuntimeError("host matching enabled and a subdomain was provided") elif subdomain is None: subdomain = self.default_subdomain if script_name is None: script_name = "/" if path_info is None: path_info = "/" try: server_name = _encode_idna(server_name) # type: ignore except UnicodeError as e: raise BadHost() from e return MapAdapter( self, server_name, script_name, subdomain, url_scheme, path_info, default_method, query_args, ) def bind_to_environ( self, environ: t.Union["WSGIEnvironment", "Request"], server_name: t.Optional[str] = None, subdomain: t.Optional[str] = None, ) -> "MapAdapter": """Like :meth:`bind` but you can pass it an WSGI environment and it will fetch the information from that dictionary. Note that because of limitations in the protocol there is no way to get the current subdomain and real `server_name` from the environment. If you don't provide it, Werkzeug will use `SERVER_NAME` and `SERVER_PORT` (or `HTTP_HOST` if provided) as used `server_name` with disabled subdomain feature. If `subdomain` is `None` but an environment and a server name is provided it will calculate the current subdomain automatically. Example: `server_name` is ``'example.com'`` and the `SERVER_NAME` in the wsgi `environ` is ``'staging.dev.example.com'`` the calculated subdomain will be ``'staging.dev'``. If the object passed as environ has an environ attribute, the value of this attribute is used instead. This allows you to pass request objects. Additionally `PATH_INFO` added as a default of the :class:`MapAdapter` so that you don't have to pass the path info to the match method. .. versionchanged:: 1.0.0 If the passed server name specifies port 443, it will match if the incoming scheme is ``https`` without a port. .. versionchanged:: 1.0.0 A warning is shown when the passed server name does not match the incoming WSGI server name. .. versionchanged:: 0.8 This will no longer raise a ValueError when an unexpected server name was passed. .. versionchanged:: 0.5 previously this method accepted a bogus `calculate_subdomain` parameter that did not have any effect. It was removed because of that. :param environ: a WSGI environment. :param server_name: an optional server name hint (see above). :param subdomain: optionally the current subdomain (see above). """ env = _get_environ(environ) wsgi_server_name = get_host(env).lower() scheme = env["wsgi.url_scheme"] upgrade = any( v.strip() == "upgrade" for v in env.get("HTTP_CONNECTION", "").lower().split(",") ) if upgrade and env.get("HTTP_UPGRADE", "").lower() == "websocket": scheme = "wss" if scheme == "https" else "ws" if server_name is None: server_name = wsgi_server_name else: server_name = server_name.lower() # strip standard port to match get_host() if scheme in {"http", "ws"} and server_name.endswith(":80"): server_name = server_name[:-3] elif scheme in {"https", "wss"} and server_name.endswith(":443"): server_name = server_name[:-4] if subdomain is None and not self.host_matching: cur_server_name = wsgi_server_name.split(".") real_server_name = server_name.split(".") offset = -len(real_server_name) if cur_server_name[offset:] != real_server_name: # This can happen even with valid configs if the server was # accessed directly by IP address under some situations. # Instead of raising an exception like in Werkzeug 0.7 or # earlier we go by an invalid subdomain which will result # in a 404 error on matching. warnings.warn( f"Current server name {wsgi_server_name!r} doesn't match configured" f" server name {server_name!r}", stacklevel=2, ) subdomain = "" else: subdomain = ".".join(filter(None, cur_server_name[:offset])) def _get_wsgi_string(name: str) -> t.Optional[str]: val = env.get(name) if val is not None: return _wsgi_decoding_dance(val, self.charset) return None script_name = _get_wsgi_string("SCRIPT_NAME") path_info = _get_wsgi_string("PATH_INFO") query_args = _get_wsgi_string("QUERY_STRING") return Map.bind( self, server_name, script_name, subdomain, scheme, env["REQUEST_METHOD"], path_info, query_args=query_args, ) def update(self) -> None: """Called before matching and building to keep the compiled rules in the correct order after things changed. """ if not self._remap: return with self._remap_lock: if not self._remap: return self._rules.sort(key=lambda x: x.match_compare_key()) for rules in self._rules_by_endpoint.values(): rules.sort(key=lambda x: x.build_compare_key()) self._remap = False def __repr__(self) -> str: rules = self.iter_rules() return f"{type(self).__name__}({pformat(list(rules))})" class MapAdapter: """Returned by :meth:`Map.bind` or :meth:`Map.bind_to_environ` and does the URL matching and building based on runtime information. """ def __init__( self, map: Map, server_name: str, script_name: str, subdomain: t.Optional[str], url_scheme: str, path_info: str, default_method: str, query_args: t.Optional[t.Union[t.Mapping[str, t.Any], str]] = None, ): self.map = map self.server_name = _to_str(server_name) script_name = _to_str(script_name) if not script_name.endswith("/"): script_name += "/" self.script_name = script_name self.subdomain = _to_str(subdomain) self.url_scheme = _to_str(url_scheme) self.path_info = _to_str(path_info) self.default_method = _to_str(default_method) self.query_args = query_args self.websocket = self.url_scheme in {"ws", "wss"} def dispatch( self, view_func: t.Callable[[str, t.Mapping[str, t.Any]], "WSGIApplication"], path_info: t.Optional[str] = None, method: t.Optional[str] = None, catch_http_exceptions: bool = False, ) -> "WSGIApplication": """Does the complete dispatching process. `view_func` is called with the endpoint and a dict with the values for the view. It should look up the view function, call it, and return a response object or WSGI application. http exceptions are not caught by default so that applications can display nicer error messages by just catching them by hand. If you want to stick with the default error messages you can pass it ``catch_http_exceptions=True`` and it will catch the http exceptions. Here a small example for the dispatch usage:: from werkzeug.wrappers import Request, Response from werkzeug.wsgi import responder from werkzeug.routing import Map, Rule def on_index(request): return Response('Hello from the index') url_map = Map([Rule('/', endpoint='index')]) views = {'index': on_index} @responder def application(environ, start_response): request = Request(environ) urls = url_map.bind_to_environ(environ) return urls.dispatch(lambda e, v: views[e](request, **v), catch_http_exceptions=True) Keep in mind that this method might return exception objects, too, so use :class:`Response.force_type` to get a response object. :param view_func: a function that is called with the endpoint as first argument and the value dict as second. Has to dispatch to the actual view function with this information. (see above) :param path_info: the path info to use for matching. Overrides the path info specified on binding. :param method: the HTTP method used for matching. Overrides the method specified on binding. :param catch_http_exceptions: set to `True` to catch any of the werkzeug :class:`HTTPException`\\s. """ try: try: endpoint, args = self.match(path_info, method) except RequestRedirect as e: return e return view_func(endpoint, args) except HTTPException as e: if catch_http_exceptions: return e raise @typing.overload def match( # type: ignore self, path_info: t.Optional[str] = None, method: t.Optional[str] = None, return_rule: "te.Literal[False]" = False, query_args: t.Optional[t.Union[t.Mapping[str, t.Any], str]] = None, websocket: t.Optional[bool] = None, ) -> t.Tuple[str, t.Mapping[str, t.Any]]: ... @typing.overload def match( self, path_info: t.Optional[str] = None, method: t.Optional[str] = None, return_rule: "te.Literal[True]" = True, query_args: t.Optional[t.Union[t.Mapping[str, t.Any], str]] = None, websocket: t.Optional[bool] = None, ) -> t.Tuple[Rule, t.Mapping[str, t.Any]]: ... def match( self, path_info: t.Optional[str] = None, method: t.Optional[str] = None, return_rule: bool = False, query_args: t.Optional[t.Union[t.Mapping[str, t.Any], str]] = None, websocket: t.Optional[bool] = None, ) -> t.Tuple[t.Union[str, Rule], t.Mapping[str, t.Any]]: """The usage is simple: you just pass the match method the current path info as well as the method (which defaults to `GET`). The following things can then happen: - you receive a `NotFound` exception that indicates that no URL is matching. A `NotFound` exception is also a WSGI application you can call to get a default page not found page (happens to be the same object as `werkzeug.exceptions.NotFound`) - you receive a `MethodNotAllowed` exception that indicates that there is a match for this URL but not for the current request method. This is useful for RESTful applications. - you receive a `RequestRedirect` exception with a `new_url` attribute. This exception is used to notify you about a request Werkzeug requests from your WSGI application. This is for example the case if you request ``/foo`` although the correct URL is ``/foo/`` You can use the `RequestRedirect` instance as response-like object similar to all other subclasses of `HTTPException`. - you receive a ``WebsocketMismatch`` exception if the only match is a WebSocket rule but the bind is an HTTP request, or if the match is an HTTP rule but the bind is a WebSocket request. - you get a tuple in the form ``(endpoint, arguments)`` if there is a match (unless `return_rule` is True, in which case you get a tuple in the form ``(rule, arguments)``) If the path info is not passed to the match method the default path info of the map is used (defaults to the root URL if not defined explicitly). All of the exceptions raised are subclasses of `HTTPException` so they can be used as WSGI responses. They will all render generic error or redirect pages. Here is a small example for matching: >>> m = Map([ ... Rule('/', endpoint='index'), ... Rule('/downloads/', endpoint='downloads/index'), ... Rule('/downloads/', endpoint='downloads/show') ... ]) >>> urls = m.bind("example.com", "/") >>> urls.match("/", "GET") ('index', {}) >>> urls.match("/downloads/42") ('downloads/show', {'id': 42}) And here is what happens on redirect and missing URLs: >>> urls.match("/downloads") Traceback (most recent call last): ... RequestRedirect: http://example.com/downloads/ >>> urls.match("/missing") Traceback (most recent call last): ... NotFound: 404 Not Found :param path_info: the path info to use for matching. Overrides the path info specified on binding. :param method: the HTTP method used for matching. Overrides the method specified on binding. :param return_rule: return the rule that matched instead of just the endpoint (defaults to `False`). :param query_args: optional query arguments that are used for automatic redirects as string or dictionary. It's currently not possible to use the query arguments for URL matching. :param websocket: Match WebSocket instead of HTTP requests. A websocket request has a ``ws`` or ``wss`` :attr:`url_scheme`. This overrides that detection. .. versionadded:: 1.0 Added ``websocket``. .. versionchanged:: 0.8 ``query_args`` can be a string. .. versionadded:: 0.7 Added ``query_args``. .. versionadded:: 0.6 Added ``return_rule``. """ self.map.update() if path_info is None: path_info = self.path_info else: path_info = _to_str(path_info, self.map.charset) if query_args is None: query_args = self.query_args or {} method = (method or self.default_method).upper() if websocket is None: websocket = self.websocket require_redirect = False domain_part = self.server_name if self.map.host_matching else self.subdomain path_part = f"/{path_info.lstrip('/')}" if path_info else "" path = f"{domain_part}|{path_part}" have_match_for = set() websocket_mismatch = False for rule in self.map._rules: try: rv = rule.match(path, method) except RequestPath as e: raise RequestRedirect( self.make_redirect_url( url_quote(e.path_info, self.map.charset, safe="/:|+"), query_args, ) ) from None except RequestAliasRedirect as e: raise RequestRedirect( self.make_alias_redirect_url( path, rule.endpoint, e.matched_values, method, query_args ) ) from None if rv is None: continue if rule.methods is not None and method not in rule.methods: have_match_for.update(rule.methods) continue if rule.websocket != websocket: websocket_mismatch = True continue if self.map.redirect_defaults: redirect_url = self.get_default_redirect(rule, method, rv, query_args) if redirect_url is not None: raise RequestRedirect(redirect_url) if rule.redirect_to is not None: if isinstance(rule.redirect_to, str): def _handle_match(match: t.Match[str]) -> str: value = rv[match.group(1)] # type: ignore return rule._converters[match.group(1)].to_url(value) redirect_url = _simple_rule_re.sub(_handle_match, rule.redirect_to) else: redirect_url = rule.redirect_to(self, **rv) if self.subdomain: netloc = f"{self.subdomain}.{self.server_name}" else: netloc = self.server_name raise RequestRedirect( url_join( f"{self.url_scheme or 'http'}://{netloc}{self.script_name}", redirect_url, ) ) if require_redirect: raise RequestRedirect( self.make_redirect_url( url_quote(path_info, self.map.charset, safe="/:|+"), query_args ) ) if return_rule: return rule, rv else: return rule.endpoint, rv if have_match_for: raise MethodNotAllowed(valid_methods=list(have_match_for)) if websocket_mismatch: raise WebsocketMismatch() raise NotFound() def test( self, path_info: t.Optional[str] = None, method: t.Optional[str] = None ) -> bool: """Test if a rule would match. Works like `match` but returns `True` if the URL matches, or `False` if it does not exist. :param path_info: the path info to use for matching. Overrides the path info specified on binding. :param method: the HTTP method used for matching. Overrides the method specified on binding. """ try: self.match(path_info, method) except RequestRedirect: pass except HTTPException: return False return True def allowed_methods(self, path_info: t.Optional[str] = None) -> t.Iterable[str]: """Returns the valid methods that match for a given path. .. versionadded:: 0.7 """ try: self.match(path_info, method="--") except MethodNotAllowed as e: return e.valid_methods # type: ignore except HTTPException: pass return [] def get_host(self, domain_part: t.Optional[str]) -> str: """Figures out the full host name for the given domain part. The domain part is a subdomain in case host matching is disabled or a full host name. """ if self.map.host_matching: if domain_part is None: return self.server_name return _to_str(domain_part, "ascii") subdomain = domain_part if subdomain is None: subdomain = self.subdomain else: subdomain = _to_str(subdomain, "ascii") if subdomain: return f"{subdomain}.{self.server_name}" else: return self.server_name def get_default_redirect( self, rule: Rule, method: str, values: t.MutableMapping[str, t.Any], query_args: t.Union[t.Mapping[str, t.Any], str], ) -> t.Optional[str]: """A helper that returns the URL to redirect to if it finds one. This is used for default redirecting only. :internal: """ assert self.map.redirect_defaults for r in self.map._rules_by_endpoint[rule.endpoint]: # every rule that comes after this one, including ourself # has a lower priority for the defaults. We order the ones # with the highest priority up for building. if r is rule: break if r.provides_defaults_for(rule) and r.suitable_for(values, method): values.update(r.defaults) # type: ignore domain_part, path = r.build(values) # type: ignore return self.make_redirect_url(path, query_args, domain_part=domain_part) return None def encode_query_args(self, query_args: t.Union[t.Mapping[str, t.Any], str]) -> str: if not isinstance(query_args, str): return url_encode(query_args, self.map.charset) return query_args def make_redirect_url( self, path_info: str, query_args: t.Optional[t.Union[t.Mapping[str, t.Any], str]] = None, domain_part: t.Optional[str] = None, ) -> str: """Creates a redirect URL. :internal: """ if query_args: suffix = f"?{self.encode_query_args(query_args)}" else: suffix = "" scheme = self.url_scheme or "http" host = self.get_host(domain_part) path = posixpath.join(self.script_name.strip("/"), path_info.lstrip("/")) return f"{scheme}://{host}/{path}{suffix}" def make_alias_redirect_url( self, path: str, endpoint: str, values: t.Mapping[str, t.Any], method: str, query_args: t.Union[t.Mapping[str, t.Any], str], ) -> str: """Internally called to make an alias redirect URL.""" url = self.build( endpoint, values, method, append_unknown=False, force_external=True ) if query_args: url += f"?{self.encode_query_args(query_args)}" assert url != path, "detected invalid alias setting. No canonical URL found" return url def _partial_build( self, endpoint: str, values: t.Mapping[str, t.Any], method: t.Optional[str], append_unknown: bool, ) -> t.Optional[t.Tuple[str, str, bool]]: """Helper for :meth:`build`. Returns subdomain and path for the rule that accepts this endpoint, values and method. :internal: """ # in case the method is none, try with the default method first if method is None: rv = self._partial_build( endpoint, values, self.default_method, append_unknown ) if rv is not None: return rv # Default method did not match or a specific method is passed. # Check all for first match with matching host. If no matching # host is found, go with first result. first_match = None for rule in self.map._rules_by_endpoint.get(endpoint, ()): if rule.suitable_for(values, method): build_rv = rule.build(values, append_unknown) if build_rv is not None: rv = (build_rv[0], build_rv[1], rule.websocket) if self.map.host_matching: if rv[0] == self.server_name: return rv elif first_match is None: first_match = rv else: return rv return first_match def build( self, endpoint: str, values: t.Optional[t.Mapping[str, t.Any]] = None, method: t.Optional[str] = None, force_external: bool = False, append_unknown: bool = True, url_scheme: t.Optional[str] = None, ) -> str: """Building URLs works pretty much the other way round. Instead of `match` you call `build` and pass it the endpoint and a dict of arguments for the placeholders. The `build` function also accepts an argument called `force_external` which, if you set it to `True` will force external URLs. Per default external URLs (include the server name) will only be used if the target URL is on a different subdomain. >>> m = Map([ ... Rule('/', endpoint='index'), ... Rule('/downloads/', endpoint='downloads/index'), ... Rule('/downloads/', endpoint='downloads/show') ... ]) >>> urls = m.bind("example.com", "/") >>> urls.build("index", {}) '/' >>> urls.build("downloads/show", {'id': 42}) '/downloads/42' >>> urls.build("downloads/show", {'id': 42}, force_external=True) 'http://example.com/downloads/42' Because URLs cannot contain non ASCII data you will always get bytes back. Non ASCII characters are urlencoded with the charset defined on the map instance. Additional values are converted to strings and appended to the URL as URL querystring parameters: >>> urls.build("index", {'q': 'My Searchstring'}) '/?q=My+Searchstring' When processing those additional values, lists are furthermore interpreted as multiple values (as per :py:class:`werkzeug.datastructures.MultiDict`): >>> urls.build("index", {'q': ['a', 'b', 'c']}) '/?q=a&q=b&q=c' Passing a ``MultiDict`` will also add multiple values: >>> urls.build("index", MultiDict((('p', 'z'), ('q', 'a'), ('q', 'b')))) '/?p=z&q=a&q=b' If a rule does not exist when building a `BuildError` exception is raised. The build method accepts an argument called `method` which allows you to specify the method you want to have an URL built for if you have different methods for the same endpoint specified. :param endpoint: the endpoint of the URL to build. :param values: the values for the URL to build. Unhandled values are appended to the URL as query parameters. :param method: the HTTP method for the rule if there are different URLs for different methods on the same endpoint. :param force_external: enforce full canonical external URLs. If the URL scheme is not provided, this will generate a protocol-relative URL. :param append_unknown: unknown parameters are appended to the generated URL as query string argument. Disable this if you want the builder to ignore those. :param url_scheme: Scheme to use in place of the bound :attr:`url_scheme`. .. versionchanged:: 2.0 Added the ``url_scheme`` parameter. .. versionadded:: 0.6 Added the ``append_unknown`` parameter. """ self.map.update() if values: temp_values: t.Dict[str, t.Union[t.List[t.Any], t.Any]] = {} always_list = isinstance(values, MultiDict) key: str value: t.Optional[t.Union[t.List[t.Any], t.Any]] # For MultiDict, dict.items(values) is like values.lists() # without the call or list coercion overhead. for key, value in dict.items(values): # type: ignore if value is None: continue if always_list or isinstance(value, (list, tuple)): value = [v for v in value if v is not None] if not value: continue if len(value) == 1: value = value[0] temp_values[key] = value values = temp_values else: values = {} rv = self._partial_build(endpoint, values, method, append_unknown) if rv is None: raise BuildError(endpoint, values, method, self) domain_part, path, websocket = rv host = self.get_host(domain_part) if url_scheme is None: url_scheme = self.url_scheme # Always build WebSocket routes with the scheme (browsers # require full URLs). If bound to a WebSocket, ensure that HTTP # routes are built with an HTTP scheme. secure = url_scheme in {"https", "wss"} if websocket: force_external = True url_scheme = "wss" if secure else "ws" elif url_scheme: url_scheme = "https" if secure else "http" # shortcut this. if not force_external and ( (self.map.host_matching and host == self.server_name) or (not self.map.host_matching and domain_part == self.subdomain) ): return f"{self.script_name.rstrip('/')}/{path.lstrip('/')}" scheme = f"{url_scheme}:" if url_scheme else "" return f"{scheme}//{host}{self.script_name[:-1]}/{path.lstrip('/')}"