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author | sotech117 <michael_foiani@brown.edu> | 2025-07-31 17:27:24 -0400 |
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committer | sotech117 <michael_foiani@brown.edu> | 2025-07-31 17:27:24 -0400 |
commit | 5bf22fc7e3c392c8bd44315ca2d06d7dca7d084e (patch) | |
tree | 8dacb0f195df1c0788d36dd0064f6bbaa3143ede /venv/lib/python3.8/site-packages/flask/views.py | |
parent | b832d364da8c2efe09e3f75828caf73c50d01ce3 (diff) |
add code for analysis of data
Diffstat (limited to 'venv/lib/python3.8/site-packages/flask/views.py')
-rw-r--r-- | venv/lib/python3.8/site-packages/flask/views.py | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/venv/lib/python3.8/site-packages/flask/views.py b/venv/lib/python3.8/site-packages/flask/views.py new file mode 100644 index 0000000..794fdc0 --- /dev/null +++ b/venv/lib/python3.8/site-packages/flask/views.py @@ -0,0 +1,191 @@ +from __future__ import annotations + +import typing as t + +from . import typing as ft +from .globals import current_app +from .globals import request + +F = t.TypeVar("F", bound=t.Callable[..., t.Any]) + +http_method_funcs = frozenset( + ["get", "post", "head", "options", "delete", "put", "trace", "patch"] +) + + +class View: + """Subclass this class and override :meth:`dispatch_request` to + create a generic class-based view. Call :meth:`as_view` to create a + view function that creates an instance of the class with the given + arguments and calls its ``dispatch_request`` method with any URL + variables. + + See :doc:`views` for a detailed guide. + + .. code-block:: python + + class Hello(View): + init_every_request = False + + def dispatch_request(self, name): + return f"Hello, {name}!" + + app.add_url_rule( + "/hello/<name>", view_func=Hello.as_view("hello") + ) + + Set :attr:`methods` on the class to change what methods the view + accepts. + + Set :attr:`decorators` on the class to apply a list of decorators to + the generated view function. Decorators applied to the class itself + will not be applied to the generated view function! + + Set :attr:`init_every_request` to ``False`` for efficiency, unless + you need to store request-global data on ``self``. + """ + + #: The methods this view is registered for. Uses the same default + #: (``["GET", "HEAD", "OPTIONS"]``) as ``route`` and + #: ``add_url_rule`` by default. + methods: t.ClassVar[t.Collection[str] | None] = None + + #: Control whether the ``OPTIONS`` method is handled automatically. + #: Uses the same default (``True``) as ``route`` and + #: ``add_url_rule`` by default. + provide_automatic_options: t.ClassVar[bool | None] = None + + #: A list of decorators to apply, in order, to the generated view + #: function. Remember that ``@decorator`` syntax is applied bottom + #: to top, so the first decorator in the list would be the bottom + #: decorator. + #: + #: .. versionadded:: 0.8 + decorators: t.ClassVar[list[t.Callable[[F], F]]] = [] + + #: Create a new instance of this view class for every request by + #: default. If a view subclass sets this to ``False``, the same + #: instance is used for every request. + #: + #: A single instance is more efficient, especially if complex setup + #: is done during init. However, storing data on ``self`` is no + #: longer safe across requests, and :data:`~flask.g` should be used + #: instead. + #: + #: .. versionadded:: 2.2 + init_every_request: t.ClassVar[bool] = True + + def dispatch_request(self) -> ft.ResponseReturnValue: + """The actual view function behavior. Subclasses must override + this and return a valid response. Any variables from the URL + rule are passed as keyword arguments. + """ + raise NotImplementedError() + + @classmethod + def as_view( + cls, name: str, *class_args: t.Any, **class_kwargs: t.Any + ) -> ft.RouteCallable: + """Convert the class into a view function that can be registered + for a route. + + By default, the generated view will create a new instance of the + view class for every request and call its + :meth:`dispatch_request` method. If the view class sets + :attr:`init_every_request` to ``False``, the same instance will + be used for every request. + + Except for ``name``, all other arguments passed to this method + are forwarded to the view class ``__init__`` method. + + .. versionchanged:: 2.2 + Added the ``init_every_request`` class attribute. + """ + if cls.init_every_request: + + def view(**kwargs: t.Any) -> ft.ResponseReturnValue: + self = view.view_class( # type: ignore[attr-defined] + *class_args, **class_kwargs + ) + return current_app.ensure_sync(self.dispatch_request)(**kwargs) # type: ignore[no-any-return] + + else: + self = cls(*class_args, **class_kwargs) + + def view(**kwargs: t.Any) -> ft.ResponseReturnValue: + return current_app.ensure_sync(self.dispatch_request)(**kwargs) # type: ignore[no-any-return] + + if cls.decorators: + view.__name__ = name + view.__module__ = cls.__module__ + for decorator in cls.decorators: + view = decorator(view) + + # We attach the view class to the view function for two reasons: + # first of all it allows us to easily figure out what class-based + # view this thing came from, secondly it's also used for instantiating + # the view class so you can actually replace it with something else + # for testing purposes and debugging. + view.view_class = cls # type: ignore + view.__name__ = name + view.__doc__ = cls.__doc__ + view.__module__ = cls.__module__ + view.methods = cls.methods # type: ignore + view.provide_automatic_options = cls.provide_automatic_options # type: ignore + return view + + +class MethodView(View): + """Dispatches request methods to the corresponding instance methods. + For example, if you implement a ``get`` method, it will be used to + handle ``GET`` requests. + + This can be useful for defining a REST API. + + :attr:`methods` is automatically set based on the methods defined on + the class. + + See :doc:`views` for a detailed guide. + + .. code-block:: python + + class CounterAPI(MethodView): + def get(self): + return str(session.get("counter", 0)) + + def post(self): + session["counter"] = session.get("counter", 0) + 1 + return redirect(url_for("counter")) + + app.add_url_rule( + "/counter", view_func=CounterAPI.as_view("counter") + ) + """ + + def __init_subclass__(cls, **kwargs: t.Any) -> None: + super().__init_subclass__(**kwargs) + + if "methods" not in cls.__dict__: + methods = set() + + for base in cls.__bases__: + if getattr(base, "methods", None): + methods.update(base.methods) # type: ignore[attr-defined] + + for key in http_method_funcs: + if hasattr(cls, key): + methods.add(key.upper()) + + if methods: + cls.methods = methods + + def dispatch_request(self, **kwargs: t.Any) -> ft.ResponseReturnValue: + meth = getattr(self, request.method.lower(), None) + + # If the request method is HEAD and we don't have a handler for it + # retry with GET. + if meth is None and request.method == "HEAD": + meth = getattr(self, "get", None) + + assert meth is not None, f"Unimplemented method {request.method!r}" + return current_app.ensure_sync(meth)(**kwargs) # type: ignore[no-any-return] |