Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/flask/helpers.py: 29%
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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
14from werkzeug.wrappers import Response as BaseResponse
16from .globals import _cv_request
17from .globals import current_app
18from .globals import request
19from .globals import request_ctx
20from .globals import session
21from .signals import message_flashed
23if t.TYPE_CHECKING: # pragma: no cover
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: t.Iterator[t.AnyStr] | t.Callable[..., t.Iterator[t.AnyStr]],
52) -> t.Iterator[t.AnyStr]:
53 """Request contexts disappear when the response is started on the server.
54 This is done for efficiency reasons and to make it less likely to encounter
55 memory leaks with badly written WSGI middlewares. The downside is that if
56 you are using streamed responses, the generator cannot access request bound
57 information any more.
59 This function however can help you keep the context around for longer::
61 from flask import stream_with_context, request, Response
63 @app.route('/stream')
64 def streamed_response():
65 @stream_with_context
66 def generate():
67 yield 'Hello '
68 yield request.args['name']
69 yield '!'
70 return Response(generate())
72 Alternatively it can also be used around a specific generator::
74 from flask import stream_with_context, request, Response
76 @app.route('/stream')
77 def streamed_response():
78 def generate():
79 yield 'Hello '
80 yield request.args['name']
81 yield '!'
82 return Response(stream_with_context(generate()))
84 .. versionadded:: 0.9
85 """
86 try:
87 gen = iter(generator_or_function) # type: ignore[arg-type]
88 except TypeError:
90 def decorator(*args: t.Any, **kwargs: t.Any) -> t.Any:
91 gen = generator_or_function(*args, **kwargs) # type: ignore[operator]
92 return stream_with_context(gen)
94 return update_wrapper(decorator, generator_or_function) # type: ignore[arg-type]
96 def generator() -> t.Iterator[t.AnyStr | None]:
97 ctx = _cv_request.get(None)
98 if ctx is None:
99 raise RuntimeError(
100 "'stream_with_context' can only be used when a request"
101 " context is active, such as in a view function."
102 )
103 with ctx:
104 # Dummy sentinel. Has to be inside the context block or we're
105 # not actually keeping the context around.
106 yield None
108 # The try/finally is here so that if someone passes a WSGI level
109 # iterator in we're still running the cleanup logic. Generators
110 # don't need that because they are closed on their destruction
111 # automatically.
112 try:
113 yield from gen
114 finally:
115 if hasattr(gen, "close"):
116 gen.close()
118 # The trick is to start the generator. Then the code execution runs until
119 # the first dummy None is yielded at which point the context was already
120 # pushed. This item is discarded. Then when the iteration continues the
121 # real generator is executed.
122 wrapped_g = generator()
123 next(wrapped_g)
124 return wrapped_g # type: ignore[return-value]
127def make_response(*args: t.Any) -> Response:
128 """Sometimes it is necessary to set additional headers in a view. Because
129 views do not have to return response objects but can return a value that
130 is converted into a response object by Flask itself, it becomes tricky to
131 add headers to it. This function can be called instead of using a return
132 and you will get a response object which you can use to attach headers.
134 If view looked like this and you want to add a new header::
136 def index():
137 return render_template('index.html', foo=42)
139 You can now do something like this::
141 def index():
142 response = make_response(render_template('index.html', foo=42))
143 response.headers['X-Parachutes'] = 'parachutes are cool'
144 return response
146 This function accepts the very same arguments you can return from a
147 view function. This for example creates a response with a 404 error
148 code::
150 response = make_response(render_template('not_found.html'), 404)
152 The other use case of this function is to force the return value of a
153 view function into a response which is helpful with view
154 decorators::
156 response = make_response(view_function())
157 response.headers['X-Parachutes'] = 'parachutes are cool'
159 Internally this function does the following things:
161 - if no arguments are passed, it creates a new response argument
162 - if one argument is passed, :meth:`flask.Flask.make_response`
163 is invoked with it.
164 - if more than one argument is passed, the arguments are passed
165 to the :meth:`flask.Flask.make_response` function as tuple.
167 .. versionadded:: 0.6
168 """
169 if not args:
170 return current_app.response_class()
171 if len(args) == 1:
172 args = args[0]
173 return current_app.make_response(args)
176def url_for(
177 endpoint: str,
178 *,
179 _anchor: str | None = None,
180 _method: str | None = None,
181 _scheme: str | None = None,
182 _external: bool | None = None,
183 **values: t.Any,
184) -> str:
185 """Generate a URL to the given endpoint with the given values.
187 This requires an active request or application context, and calls
188 :meth:`current_app.url_for() <flask.Flask.url_for>`. See that method
189 for full documentation.
191 :param endpoint: The endpoint name associated with the URL to
192 generate. If this starts with a ``.``, the current blueprint
193 name (if any) will be used.
194 :param _anchor: If given, append this as ``#anchor`` to the URL.
195 :param _method: If given, generate the URL associated with this
196 method for the endpoint.
197 :param _scheme: If given, the URL will have this scheme if it is
198 external.
199 :param _external: If given, prefer the URL to be internal (False) or
200 require it to be external (True). External URLs include the
201 scheme and domain. When not in an active request, URLs are
202 external by default.
203 :param values: Values to use for the variable parts of the URL rule.
204 Unknown keys are appended as query string arguments, like
205 ``?a=b&c=d``.
207 .. versionchanged:: 2.2
208 Calls ``current_app.url_for``, allowing an app to override the
209 behavior.
211 .. versionchanged:: 0.10
212 The ``_scheme`` parameter was added.
214 .. versionchanged:: 0.9
215 The ``_anchor`` and ``_method`` parameters were added.
217 .. versionchanged:: 0.9
218 Calls ``app.handle_url_build_error`` on build errors.
219 """
220 return current_app.url_for(
221 endpoint,
222 _anchor=_anchor,
223 _method=_method,
224 _scheme=_scheme,
225 _external=_external,
226 **values,
227 )
230def redirect(
231 location: str, code: int = 302, Response: type[BaseResponse] | None = None
232) -> BaseResponse:
233 """Create a redirect response object.
235 If :data:`~flask.current_app` is available, it will use its
236 :meth:`~flask.Flask.redirect` method, otherwise it will use
237 :func:`werkzeug.utils.redirect`.
239 :param location: The URL to redirect to.
240 :param code: The status code for the redirect.
241 :param Response: The response class to use. Not used when
242 ``current_app`` is active, which uses ``app.response_class``.
244 .. versionadded:: 2.2
245 Calls ``current_app.redirect`` if available instead of always
246 using Werkzeug's default ``redirect``.
247 """
248 if current_app:
249 return current_app.redirect(location, code=code)
251 return _wz_redirect(location, code=code, Response=Response)
254def abort(code: int | BaseResponse, *args: t.Any, **kwargs: t.Any) -> t.NoReturn:
255 """Raise an :exc:`~werkzeug.exceptions.HTTPException` for the given
256 status code.
258 If :data:`~flask.current_app` is available, it will call its
259 :attr:`~flask.Flask.aborter` object, otherwise it will use
260 :func:`werkzeug.exceptions.abort`.
262 :param code: The status code for the exception, which must be
263 registered in ``app.aborter``.
264 :param args: Passed to the exception.
265 :param kwargs: Passed to the exception.
267 .. versionadded:: 2.2
268 Calls ``current_app.aborter`` if available instead of always
269 using Werkzeug's default ``abort``.
270 """
271 if current_app:
272 current_app.aborter(code, *args, **kwargs)
274 _wz_abort(code, *args, **kwargs)
277def get_template_attribute(template_name: str, attribute: str) -> t.Any:
278 """Loads a macro (or variable) a template exports. This can be used to
279 invoke a macro from within Python code. If you for example have a
280 template named :file:`_cider.html` with the following contents:
282 .. sourcecode:: html+jinja
284 {% macro hello(name) %}Hello {{ name }}!{% endmacro %}
286 You can access this from Python code like this::
288 hello = get_template_attribute('_cider.html', 'hello')
289 return hello('World')
291 .. versionadded:: 0.2
293 :param template_name: the name of the template
294 :param attribute: the name of the variable of macro to access
295 """
296 return getattr(current_app.jinja_env.get_template(template_name).module, attribute)
299def flash(message: str, category: str = "message") -> None:
300 """Flashes a message to the next request. In order to remove the
301 flashed message from the session and to display it to the user,
302 the template has to call :func:`get_flashed_messages`.
304 .. versionchanged:: 0.3
305 `category` parameter added.
307 :param message: the message to be flashed.
308 :param category: the category for the message. The following values
309 are recommended: ``'message'`` for any kind of message,
310 ``'error'`` for errors, ``'info'`` for information
311 messages and ``'warning'`` for warnings. However any
312 kind of string can be used as category.
313 """
314 # Original implementation:
315 #
316 # session.setdefault('_flashes', []).append((category, message))
317 #
318 # This assumed that changes made to mutable structures in the session are
319 # always in sync with the session object, which is not true for session
320 # implementations that use external storage for keeping their keys/values.
321 flashes = session.get("_flashes", [])
322 flashes.append((category, message))
323 session["_flashes"] = flashes
324 app = current_app._get_current_object() # type: ignore
325 message_flashed.send(
326 app,
327 _async_wrapper=app.ensure_sync,
328 message=message,
329 category=category,
330 )
333def get_flashed_messages(
334 with_categories: bool = False, category_filter: t.Iterable[str] = ()
335) -> list[str] | list[tuple[str, str]]:
336 """Pulls all flashed messages from the session and returns them.
337 Further calls in the same request to the function will return
338 the same messages. By default just the messages are returned,
339 but when `with_categories` is set to ``True``, the return value will
340 be a list of tuples in the form ``(category, message)`` instead.
342 Filter the flashed messages to one or more categories by providing those
343 categories in `category_filter`. This allows rendering categories in
344 separate html blocks. The `with_categories` and `category_filter`
345 arguments are distinct:
347 * `with_categories` controls whether categories are returned with message
348 text (``True`` gives a tuple, where ``False`` gives just the message text).
349 * `category_filter` filters the messages down to only those matching the
350 provided categories.
352 See :doc:`/patterns/flashing` for examples.
354 .. versionchanged:: 0.3
355 `with_categories` parameter added.
357 .. versionchanged:: 0.9
358 `category_filter` parameter added.
360 :param with_categories: set to ``True`` to also receive categories.
361 :param category_filter: filter of categories to limit return values. Only
362 categories in the list will be returned.
363 """
364 flashes = request_ctx.flashes
365 if flashes is None:
366 flashes = session.pop("_flashes") if "_flashes" in session else []
367 request_ctx.flashes = flashes
368 if category_filter:
369 flashes = list(filter(lambda f: f[0] in category_filter, flashes))
370 if not with_categories:
371 return [x[1] for x in flashes]
372 return flashes
375def _prepare_send_file_kwargs(**kwargs: t.Any) -> dict[str, t.Any]:
376 if kwargs.get("max_age") is None:
377 kwargs["max_age"] = current_app.get_send_file_max_age
379 kwargs.update(
380 environ=request.environ,
381 use_x_sendfile=current_app.config["USE_X_SENDFILE"],
382 response_class=current_app.response_class,
383 _root_path=current_app.root_path, # type: ignore
384 )
385 return kwargs
388def send_file(
389 path_or_file: os.PathLike[t.AnyStr] | str | t.BinaryIO,
390 mimetype: str | None = None,
391 as_attachment: bool = False,
392 download_name: str | None = None,
393 conditional: bool = True,
394 etag: bool | str = True,
395 last_modified: datetime | int | float | None = None,
396 max_age: None | (int | t.Callable[[str | None], int | None]) = None,
397) -> Response:
398 """Send the contents of a file to the client.
400 The first argument can be a file path or a file-like object. Paths
401 are preferred in most cases because Werkzeug can manage the file and
402 get extra information from the path. Passing a file-like object
403 requires that the file is opened in binary mode, and is mostly
404 useful when building a file in memory with :class:`io.BytesIO`.
406 Never pass file paths provided by a user. The path is assumed to be
407 trusted, so a user could craft a path to access a file you didn't
408 intend. Use :func:`send_from_directory` to safely serve
409 user-requested paths from within a directory.
411 If the WSGI server sets a ``file_wrapper`` in ``environ``, it is
412 used, otherwise Werkzeug's built-in wrapper is used. Alternatively,
413 if the HTTP server supports ``X-Sendfile``, configuring Flask with
414 ``USE_X_SENDFILE = True`` will tell the server to send the given
415 path, which is much more efficient than reading it in Python.
417 :param path_or_file: The path to the file to send, relative to the
418 current working directory if a relative path is given.
419 Alternatively, a file-like object opened in binary mode. Make
420 sure the file pointer is seeked to the start of the data.
421 :param mimetype: The MIME type to send for the file. If not
422 provided, it will try to detect it from the file name.
423 :param as_attachment: Indicate to a browser that it should offer to
424 save the file instead of displaying it.
425 :param download_name: The default name browsers will use when saving
426 the file. Defaults to the passed file name.
427 :param conditional: Enable conditional and range responses based on
428 request headers. Requires passing a file path and ``environ``.
429 :param etag: Calculate an ETag for the file, which requires passing
430 a file path. Can also be a string to use instead.
431 :param last_modified: The last modified time to send for the file,
432 in seconds. If not provided, it will try to detect it from the
433 file path.
434 :param max_age: How long the client should cache the file, in
435 seconds. If set, ``Cache-Control`` will be ``public``, otherwise
436 it will be ``no-cache`` to prefer conditional caching.
438 .. versionchanged:: 2.0
439 ``download_name`` replaces the ``attachment_filename``
440 parameter. If ``as_attachment=False``, it is passed with
441 ``Content-Disposition: inline`` instead.
443 .. versionchanged:: 2.0
444 ``max_age`` replaces the ``cache_timeout`` parameter.
445 ``conditional`` is enabled and ``max_age`` is not set by
446 default.
448 .. versionchanged:: 2.0
449 ``etag`` replaces the ``add_etags`` parameter. It can be a
450 string to use instead of generating one.
452 .. versionchanged:: 2.0
453 Passing a file-like object that inherits from
454 :class:`~io.TextIOBase` will raise a :exc:`ValueError` rather
455 than sending an empty file.
457 .. versionadded:: 2.0
458 Moved the implementation to Werkzeug. This is now a wrapper to
459 pass some Flask-specific arguments.
461 .. versionchanged:: 1.1
462 ``filename`` may be a :class:`~os.PathLike` object.
464 .. versionchanged:: 1.1
465 Passing a :class:`~io.BytesIO` object supports range requests.
467 .. versionchanged:: 1.0.3
468 Filenames are encoded with ASCII instead of Latin-1 for broader
469 compatibility with WSGI servers.
471 .. versionchanged:: 1.0
472 UTF-8 filenames as specified in :rfc:`2231` are supported.
474 .. versionchanged:: 0.12
475 The filename is no longer automatically inferred from file
476 objects. If you want to use automatic MIME and etag support,
477 pass a filename via ``filename_or_fp`` or
478 ``attachment_filename``.
480 .. versionchanged:: 0.12
481 ``attachment_filename`` is preferred over ``filename`` for MIME
482 detection.
484 .. versionchanged:: 0.9
485 ``cache_timeout`` defaults to
486 :meth:`Flask.get_send_file_max_age`.
488 .. versionchanged:: 0.7
489 MIME guessing and etag support for file-like objects was
490 removed because it was unreliable. Pass a filename if you are
491 able to, otherwise attach an etag yourself.
493 .. versionchanged:: 0.5
494 The ``add_etags``, ``cache_timeout`` and ``conditional``
495 parameters were added. The default behavior is to add etags.
497 .. versionadded:: 0.2
498 """
499 return werkzeug.utils.send_file( # type: ignore[return-value]
500 **_prepare_send_file_kwargs(
501 path_or_file=path_or_file,
502 environ=request.environ,
503 mimetype=mimetype,
504 as_attachment=as_attachment,
505 download_name=download_name,
506 conditional=conditional,
507 etag=etag,
508 last_modified=last_modified,
509 max_age=max_age,
510 )
511 )
514def send_from_directory(
515 directory: os.PathLike[str] | str,
516 path: os.PathLike[str] | str,
517 **kwargs: t.Any,
518) -> Response:
519 """Send a file from within a directory using :func:`send_file`.
521 .. code-block:: python
523 @app.route("/uploads/<path:name>")
524 def download_file(name):
525 return send_from_directory(
526 app.config['UPLOAD_FOLDER'], name, as_attachment=True
527 )
529 This is a secure way to serve files from a folder, such as static
530 files or uploads. Uses :func:`~werkzeug.security.safe_join` to
531 ensure the path coming from the client is not maliciously crafted to
532 point outside the specified directory.
534 If the final path does not point to an existing regular file,
535 raises a 404 :exc:`~werkzeug.exceptions.NotFound` error.
537 :param directory: The directory that ``path`` must be located under,
538 relative to the current application's root path.
539 :param path: The path to the file to send, relative to
540 ``directory``.
541 :param kwargs: Arguments to pass to :func:`send_file`.
543 .. versionchanged:: 2.0
544 ``path`` replaces the ``filename`` parameter.
546 .. versionadded:: 2.0
547 Moved the implementation to Werkzeug. This is now a wrapper to
548 pass some Flask-specific arguments.
550 .. versionadded:: 0.5
551 """
552 return werkzeug.utils.send_from_directory( # type: ignore[return-value]
553 directory, path, **_prepare_send_file_kwargs(**kwargs)
554 )
557def get_root_path(import_name: str) -> str:
558 """Find the root path of a package, or the path that contains a
559 module. If it cannot be found, returns the current working
560 directory.
562 Not to be confused with the value returned by :func:`find_package`.
564 :meta private:
565 """
566 # Module already imported and has a file attribute. Use that first.
567 mod = sys.modules.get(import_name)
569 if mod is not None and hasattr(mod, "__file__") and mod.__file__ is not None:
570 return os.path.dirname(os.path.abspath(mod.__file__))
572 # Next attempt: check the loader.
573 try:
574 spec = importlib.util.find_spec(import_name)
576 if spec is None:
577 raise ValueError
578 except (ImportError, ValueError):
579 loader = None
580 else:
581 loader = spec.loader
583 # Loader does not exist or we're referring to an unloaded main
584 # module or a main module without path (interactive sessions), go
585 # with the current working directory.
586 if loader is None:
587 return os.getcwd()
589 if hasattr(loader, "get_filename"):
590 filepath = loader.get_filename(import_name)
591 else:
592 # Fall back to imports.
593 __import__(import_name)
594 mod = sys.modules[import_name]
595 filepath = getattr(mod, "__file__", None)
597 # If we don't have a file path it might be because it is a
598 # namespace package. In this case pick the root path from the
599 # first module that is contained in the package.
600 if filepath is None:
601 raise RuntimeError(
602 "No root path can be found for the provided module"
603 f" {import_name!r}. This can happen because the module"
604 " came from an import hook that does not provide file"
605 " name information or because it's a namespace package."
606 " In this case the root path needs to be explicitly"
607 " provided."
608 )
610 # filepath is import_name.py for a module, or __init__.py for a package.
611 return os.path.dirname(os.path.abspath(filepath)) # type: ignore[no-any-return]
614@lru_cache(maxsize=None)
615def _split_blueprint_path(name: str) -> list[str]:
616 out: list[str] = [name]
618 if "." in name:
619 out.extend(_split_blueprint_path(name.rpartition(".")[0]))
621 return out