Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/flask/helpers.py: 33%
116 statements
« prev ^ index » next coverage.py v7.3.2, created at 2023-12-09 07:17 +0000
1from __future__ import annotations
3import importlib.util
4import os
5import sys
6import typing as t
7from datetime import datetime
8from functools import lru_cache
9from functools import update_wrapper
11import werkzeug.utils
12from werkzeug.exceptions import abort as _wz_abort
13from werkzeug.utils import redirect as _wz_redirect
15from .globals import _cv_request
16from .globals import current_app
17from .globals import request
18from .globals import request_ctx
19from .globals import session
20from .signals import message_flashed
22if t.TYPE_CHECKING: # pragma: no cover
23 from werkzeug.wrappers import Response as BaseResponse
24 from .wrappers import Response
27def get_debug_flag() -> bool:
28 """Get whether debug mode should be enabled for the app, indicated by the
29 :envvar:`FLASK_DEBUG` environment variable. The default is ``False``.
30 """
31 val = os.environ.get("FLASK_DEBUG")
32 return bool(val and val.lower() not in {"0", "false", "no"})
35def get_load_dotenv(default: bool = True) -> bool:
36 """Get whether the user has disabled loading default dotenv files by
37 setting :envvar:`FLASK_SKIP_DOTENV`. The default is ``True``, load
38 the files.
40 :param default: What to return if the env var isn't set.
41 """
42 val = os.environ.get("FLASK_SKIP_DOTENV")
44 if not val:
45 return default
47 return val.lower() in ("0", "false", "no")
50def stream_with_context(
51 generator_or_function: (
52 t.Iterator[t.AnyStr] | t.Callable[..., t.Iterator[t.AnyStr]]
53 )
54) -> t.Iterator[t.AnyStr]:
55 """Request contexts disappear when the response is started on the server.
56 This is done for efficiency reasons and to make it less likely to encounter
57 memory leaks with badly written WSGI middlewares. The downside is that if
58 you are using streamed responses, the generator cannot access request bound
59 information any more.
61 This function however can help you keep the context around for longer::
63 from flask import stream_with_context, request, Response
65 @app.route('/stream')
66 def streamed_response():
67 @stream_with_context
68 def generate():
69 yield 'Hello '
70 yield request.args['name']
71 yield '!'
72 return Response(generate())
74 Alternatively it can also be used around a specific generator::
76 from flask import stream_with_context, request, Response
78 @app.route('/stream')
79 def streamed_response():
80 def generate():
81 yield 'Hello '
82 yield request.args['name']
83 yield '!'
84 return Response(stream_with_context(generate()))
86 .. versionadded:: 0.9
87 """
88 try:
89 gen = iter(generator_or_function) # type: ignore
90 except TypeError:
92 def decorator(*args: t.Any, **kwargs: t.Any) -> t.Any:
93 gen = generator_or_function(*args, **kwargs) # type: ignore
94 return stream_with_context(gen)
96 return update_wrapper(decorator, generator_or_function) # type: ignore
98 def generator() -> t.Generator:
99 ctx = _cv_request.get(None)
100 if ctx is None:
101 raise RuntimeError(
102 "'stream_with_context' can only be used when a request"
103 " context is active, such as in a view function."
104 )
105 with ctx:
106 # Dummy sentinel. Has to be inside the context block or we're
107 # not actually keeping the context around.
108 yield None
110 # The try/finally is here so that if someone passes a WSGI level
111 # iterator in we're still running the cleanup logic. Generators
112 # don't need that because they are closed on their destruction
113 # automatically.
114 try:
115 yield from gen
116 finally:
117 if hasattr(gen, "close"):
118 gen.close()
120 # The trick is to start the generator. Then the code execution runs until
121 # the first dummy None is yielded at which point the context was already
122 # pushed. This item is discarded. Then when the iteration continues the
123 # real generator is executed.
124 wrapped_g = generator()
125 next(wrapped_g)
126 return wrapped_g
129def make_response(*args: t.Any) -> Response:
130 """Sometimes it is necessary to set additional headers in a view. Because
131 views do not have to return response objects but can return a value that
132 is converted into a response object by Flask itself, it becomes tricky to
133 add headers to it. This function can be called instead of using a return
134 and you will get a response object which you can use to attach headers.
136 If view looked like this and you want to add a new header::
138 def index():
139 return render_template('index.html', foo=42)
141 You can now do something like this::
143 def index():
144 response = make_response(render_template('index.html', foo=42))
145 response.headers['X-Parachutes'] = 'parachutes are cool'
146 return response
148 This function accepts the very same arguments you can return from a
149 view function. This for example creates a response with a 404 error
150 code::
152 response = make_response(render_template('not_found.html'), 404)
154 The other use case of this function is to force the return value of a
155 view function into a response which is helpful with view
156 decorators::
158 response = make_response(view_function())
159 response.headers['X-Parachutes'] = 'parachutes are cool'
161 Internally this function does the following things:
163 - if no arguments are passed, it creates a new response argument
164 - if one argument is passed, :meth:`flask.Flask.make_response`
165 is invoked with it.
166 - if more than one argument is passed, the arguments are passed
167 to the :meth:`flask.Flask.make_response` function as tuple.
169 .. versionadded:: 0.6
170 """
171 if not args:
172 return current_app.response_class()
173 if len(args) == 1:
174 args = args[0]
175 return current_app.make_response(args) # type: ignore
178def url_for(
179 endpoint: str,
180 *,
181 _anchor: str | None = None,
182 _method: str | None = None,
183 _scheme: str | None = None,
184 _external: bool | None = None,
185 **values: t.Any,
186) -> str:
187 """Generate a URL to the given endpoint with the given values.
189 This requires an active request or application context, and calls
190 :meth:`current_app.url_for() <flask.Flask.url_for>`. See that method
191 for full documentation.
193 :param endpoint: The endpoint name associated with the URL to
194 generate. If this starts with a ``.``, the current blueprint
195 name (if any) will be used.
196 :param _anchor: If given, append this as ``#anchor`` to the URL.
197 :param _method: If given, generate the URL associated with this
198 method for the endpoint.
199 :param _scheme: If given, the URL will have this scheme if it is
200 external.
201 :param _external: If given, prefer the URL to be internal (False) or
202 require it to be external (True). External URLs include the
203 scheme and domain. When not in an active request, URLs are
204 external by default.
205 :param values: Values to use for the variable parts of the URL rule.
206 Unknown keys are appended as query string arguments, like
207 ``?a=b&c=d``.
209 .. versionchanged:: 2.2
210 Calls ``current_app.url_for``, allowing an app to override the
211 behavior.
213 .. versionchanged:: 0.10
214 The ``_scheme`` parameter was added.
216 .. versionchanged:: 0.9
217 The ``_anchor`` and ``_method`` parameters were added.
219 .. versionchanged:: 0.9
220 Calls ``app.handle_url_build_error`` on build errors.
221 """
222 return current_app.url_for(
223 endpoint,
224 _anchor=_anchor,
225 _method=_method,
226 _scheme=_scheme,
227 _external=_external,
228 **values,
229 )
232def redirect(
233 location: str, code: int = 302, Response: type[BaseResponse] | None = None
234) -> BaseResponse:
235 """Create a redirect response object.
237 If :data:`~flask.current_app` is available, it will use its
238 :meth:`~flask.Flask.redirect` method, otherwise it will use
239 :func:`werkzeug.utils.redirect`.
241 :param location: The URL to redirect to.
242 :param code: The status code for the redirect.
243 :param Response: The response class to use. Not used when
244 ``current_app`` is active, which uses ``app.response_class``.
246 .. versionadded:: 2.2
247 Calls ``current_app.redirect`` if available instead of always
248 using Werkzeug's default ``redirect``.
249 """
250 if current_app:
251 return current_app.redirect(location, code=code)
253 return _wz_redirect(location, code=code, Response=Response)
256def abort(code: int | BaseResponse, *args: t.Any, **kwargs: t.Any) -> t.NoReturn:
257 """Raise an :exc:`~werkzeug.exceptions.HTTPException` for the given
258 status code.
260 If :data:`~flask.current_app` is available, it will call its
261 :attr:`~flask.Flask.aborter` object, otherwise it will use
262 :func:`werkzeug.exceptions.abort`.
264 :param code: The status code for the exception, which must be
265 registered in ``app.aborter``.
266 :param args: Passed to the exception.
267 :param kwargs: Passed to the exception.
269 .. versionadded:: 2.2
270 Calls ``current_app.aborter`` if available instead of always
271 using Werkzeug's default ``abort``.
272 """
273 if current_app:
274 current_app.aborter(code, *args, **kwargs)
276 _wz_abort(code, *args, **kwargs)
279def get_template_attribute(template_name: str, attribute: str) -> t.Any:
280 """Loads a macro (or variable) a template exports. This can be used to
281 invoke a macro from within Python code. If you for example have a
282 template named :file:`_cider.html` with the following contents:
284 .. sourcecode:: html+jinja
286 {% macro hello(name) %}Hello {{ name }}!{% endmacro %}
288 You can access this from Python code like this::
290 hello = get_template_attribute('_cider.html', 'hello')
291 return hello('World')
293 .. versionadded:: 0.2
295 :param template_name: the name of the template
296 :param attribute: the name of the variable of macro to access
297 """
298 return getattr(current_app.jinja_env.get_template(template_name).module, attribute)
301def flash(message: str, category: str = "message") -> None:
302 """Flashes a message to the next request. In order to remove the
303 flashed message from the session and to display it to the user,
304 the template has to call :func:`get_flashed_messages`.
306 .. versionchanged:: 0.3
307 `category` parameter added.
309 :param message: the message to be flashed.
310 :param category: the category for the message. The following values
311 are recommended: ``'message'`` for any kind of message,
312 ``'error'`` for errors, ``'info'`` for information
313 messages and ``'warning'`` for warnings. However any
314 kind of string can be used as category.
315 """
316 # Original implementation:
317 #
318 # session.setdefault('_flashes', []).append((category, message))
319 #
320 # This assumed that changes made to mutable structures in the session are
321 # always in sync with the session object, which is not true for session
322 # implementations that use external storage for keeping their keys/values.
323 flashes = session.get("_flashes", [])
324 flashes.append((category, message))
325 session["_flashes"] = flashes
326 app = current_app._get_current_object() # type: ignore
327 message_flashed.send(
328 app,
329 _async_wrapper=app.ensure_sync,
330 message=message,
331 category=category,
332 )
335def get_flashed_messages(
336 with_categories: bool = False, category_filter: t.Iterable[str] = ()
337) -> list[str] | list[tuple[str, str]]:
338 """Pulls all flashed messages from the session and returns them.
339 Further calls in the same request to the function will return
340 the same messages. By default just the messages are returned,
341 but when `with_categories` is set to ``True``, the return value will
342 be a list of tuples in the form ``(category, message)`` instead.
344 Filter the flashed messages to one or more categories by providing those
345 categories in `category_filter`. This allows rendering categories in
346 separate html blocks. The `with_categories` and `category_filter`
347 arguments are distinct:
349 * `with_categories` controls whether categories are returned with message
350 text (``True`` gives a tuple, where ``False`` gives just the message text).
351 * `category_filter` filters the messages down to only those matching the
352 provided categories.
354 See :doc:`/patterns/flashing` for examples.
356 .. versionchanged:: 0.3
357 `with_categories` parameter added.
359 .. versionchanged:: 0.9
360 `category_filter` parameter added.
362 :param with_categories: set to ``True`` to also receive categories.
363 :param category_filter: filter of categories to limit return values. Only
364 categories in the list will be returned.
365 """
366 flashes = request_ctx.flashes
367 if flashes is None:
368 flashes = session.pop("_flashes") if "_flashes" in session else []
369 request_ctx.flashes = flashes
370 if category_filter:
371 flashes = list(filter(lambda f: f[0] in category_filter, flashes))
372 if not with_categories:
373 return [x[1] for x in flashes]
374 return flashes
377def _prepare_send_file_kwargs(**kwargs: t.Any) -> dict[str, t.Any]:
378 if kwargs.get("max_age") is None:
379 kwargs["max_age"] = current_app.get_send_file_max_age
381 kwargs.update(
382 environ=request.environ,
383 use_x_sendfile=current_app.config["USE_X_SENDFILE"],
384 response_class=current_app.response_class,
385 _root_path=current_app.root_path, # type: ignore
386 )
387 return kwargs
390def send_file(
391 path_or_file: os.PathLike | str | t.BinaryIO,
392 mimetype: str | None = None,
393 as_attachment: bool = False,
394 download_name: str | None = None,
395 conditional: bool = True,
396 etag: bool | str = True,
397 last_modified: datetime | int | float | None = None,
398 max_age: None | (int | t.Callable[[str | None], int | None]) = None,
399) -> Response:
400 """Send the contents of a file to the client.
402 The first argument can be a file path or a file-like object. Paths
403 are preferred in most cases because Werkzeug can manage the file and
404 get extra information from the path. Passing a file-like object
405 requires that the file is opened in binary mode, and is mostly
406 useful when building a file in memory with :class:`io.BytesIO`.
408 Never pass file paths provided by a user. The path is assumed to be
409 trusted, so a user could craft a path to access a file you didn't
410 intend. Use :func:`send_from_directory` to safely serve
411 user-requested paths from within a directory.
413 If the WSGI server sets a ``file_wrapper`` in ``environ``, it is
414 used, otherwise Werkzeug's built-in wrapper is used. Alternatively,
415 if the HTTP server supports ``X-Sendfile``, configuring Flask with
416 ``USE_X_SENDFILE = True`` will tell the server to send the given
417 path, which is much more efficient than reading it in Python.
419 :param path_or_file: The path to the file to send, relative to the
420 current working directory if a relative path is given.
421 Alternatively, a file-like object opened in binary mode. Make
422 sure the file pointer is seeked to the start of the data.
423 :param mimetype: The MIME type to send for the file. If not
424 provided, it will try to detect it from the file name.
425 :param as_attachment: Indicate to a browser that it should offer to
426 save the file instead of displaying it.
427 :param download_name: The default name browsers will use when saving
428 the file. Defaults to the passed file name.
429 :param conditional: Enable conditional and range responses based on
430 request headers. Requires passing a file path and ``environ``.
431 :param etag: Calculate an ETag for the file, which requires passing
432 a file path. Can also be a string to use instead.
433 :param last_modified: The last modified time to send for the file,
434 in seconds. If not provided, it will try to detect it from the
435 file path.
436 :param max_age: How long the client should cache the file, in
437 seconds. If set, ``Cache-Control`` will be ``public``, otherwise
438 it will be ``no-cache`` to prefer conditional caching.
440 .. versionchanged:: 2.0
441 ``download_name`` replaces the ``attachment_filename``
442 parameter. If ``as_attachment=False``, it is passed with
443 ``Content-Disposition: inline`` instead.
445 .. versionchanged:: 2.0
446 ``max_age`` replaces the ``cache_timeout`` parameter.
447 ``conditional`` is enabled and ``max_age`` is not set by
448 default.
450 .. versionchanged:: 2.0
451 ``etag`` replaces the ``add_etags`` parameter. It can be a
452 string to use instead of generating one.
454 .. versionchanged:: 2.0
455 Passing a file-like object that inherits from
456 :class:`~io.TextIOBase` will raise a :exc:`ValueError` rather
457 than sending an empty file.
459 .. versionadded:: 2.0
460 Moved the implementation to Werkzeug. This is now a wrapper to
461 pass some Flask-specific arguments.
463 .. versionchanged:: 1.1
464 ``filename`` may be a :class:`~os.PathLike` object.
466 .. versionchanged:: 1.1
467 Passing a :class:`~io.BytesIO` object supports range requests.
469 .. versionchanged:: 1.0.3
470 Filenames are encoded with ASCII instead of Latin-1 for broader
471 compatibility with WSGI servers.
473 .. versionchanged:: 1.0
474 UTF-8 filenames as specified in :rfc:`2231` are supported.
476 .. versionchanged:: 0.12
477 The filename is no longer automatically inferred from file
478 objects. If you want to use automatic MIME and etag support,
479 pass a filename via ``filename_or_fp`` or
480 ``attachment_filename``.
482 .. versionchanged:: 0.12
483 ``attachment_filename`` is preferred over ``filename`` for MIME
484 detection.
486 .. versionchanged:: 0.9
487 ``cache_timeout`` defaults to
488 :meth:`Flask.get_send_file_max_age`.
490 .. versionchanged:: 0.7
491 MIME guessing and etag support for file-like objects was
492 removed because it was unreliable. Pass a filename if you are
493 able to, otherwise attach an etag yourself.
495 .. versionchanged:: 0.5
496 The ``add_etags``, ``cache_timeout`` and ``conditional``
497 parameters were added. The default behavior is to add etags.
499 .. versionadded:: 0.2
500 """
501 return werkzeug.utils.send_file( # type: ignore[return-value]
502 **_prepare_send_file_kwargs(
503 path_or_file=path_or_file,
504 environ=request.environ,
505 mimetype=mimetype,
506 as_attachment=as_attachment,
507 download_name=download_name,
508 conditional=conditional,
509 etag=etag,
510 last_modified=last_modified,
511 max_age=max_age,
512 )
513 )
516def send_from_directory(
517 directory: os.PathLike | str,
518 path: os.PathLike | str,
519 **kwargs: t.Any,
520) -> Response:
521 """Send a file from within a directory using :func:`send_file`.
523 .. code-block:: python
525 @app.route("/uploads/<path:name>")
526 def download_file(name):
527 return send_from_directory(
528 app.config['UPLOAD_FOLDER'], name, as_attachment=True
529 )
531 This is a secure way to serve files from a folder, such as static
532 files or uploads. Uses :func:`~werkzeug.security.safe_join` to
533 ensure the path coming from the client is not maliciously crafted to
534 point outside the specified directory.
536 If the final path does not point to an existing regular file,
537 raises a 404 :exc:`~werkzeug.exceptions.NotFound` error.
539 :param directory: The directory that ``path`` must be located under,
540 relative to the current application's root path.
541 :param path: The path to the file to send, relative to
542 ``directory``.
543 :param kwargs: Arguments to pass to :func:`send_file`.
545 .. versionchanged:: 2.0
546 ``path`` replaces the ``filename`` parameter.
548 .. versionadded:: 2.0
549 Moved the implementation to Werkzeug. This is now a wrapper to
550 pass some Flask-specific arguments.
552 .. versionadded:: 0.5
553 """
554 return werkzeug.utils.send_from_directory( # type: ignore[return-value]
555 directory, path, **_prepare_send_file_kwargs(**kwargs)
556 )
559def get_root_path(import_name: str) -> str:
560 """Find the root path of a package, or the path that contains a
561 module. If it cannot be found, returns the current working
562 directory.
564 Not to be confused with the value returned by :func:`find_package`.
566 :meta private:
567 """
568 # Module already imported and has a file attribute. Use that first.
569 mod = sys.modules.get(import_name)
571 if mod is not None and hasattr(mod, "__file__") and mod.__file__ is not None:
572 return os.path.dirname(os.path.abspath(mod.__file__))
574 # Next attempt: check the loader.
575 try:
576 spec = importlib.util.find_spec(import_name)
578 if spec is None:
579 raise ValueError
580 except (ImportError, ValueError):
581 loader = None
582 else:
583 loader = spec.loader
585 # Loader does not exist or we're referring to an unloaded main
586 # module or a main module without path (interactive sessions), go
587 # with the current working directory.
588 if loader is None:
589 return os.getcwd()
591 if hasattr(loader, "get_filename"):
592 filepath = loader.get_filename(import_name)
593 else:
594 # Fall back to imports.
595 __import__(import_name)
596 mod = sys.modules[import_name]
597 filepath = getattr(mod, "__file__", None)
599 # If we don't have a file path it might be because it is a
600 # namespace package. In this case pick the root path from the
601 # first module that is contained in the package.
602 if filepath is None:
603 raise RuntimeError(
604 "No root path can be found for the provided module"
605 f" {import_name!r}. This can happen because the module"
606 " came from an import hook that does not provide file"
607 " name information or because it's a namespace package."
608 " In this case the root path needs to be explicitly"
609 " provided."
610 )
612 # filepath is import_name.py for a module, or __init__.py for a package.
613 return os.path.dirname(os.path.abspath(filepath))
616@lru_cache(maxsize=None)
617def _split_blueprint_path(name: str) -> list[str]:
618 out: list[str] = [name]
620 if "." in name:
621 out.extend(_split_blueprint_path(name.rpartition(".")[0]))
623 return out