From 501f0431259a30569a5e62bcce68d102fc3ef993 Mon Sep 17 00:00:00 2001 From: David Lord Date: Tue, 25 Apr 2017 12:03:08 -0700 Subject: [PATCH] clean up preprocess_request docs [ci skip] --- flask/app.py | 70 ++++++++++++++++++++++++++++------------------------ 1 file changed, 38 insertions(+), 32 deletions(-) diff --git a/flask/app.py b/flask/app.py index 84f55d2c..703cfef2 100644 --- a/flask/app.py +++ b/flask/app.py @@ -415,17 +415,16 @@ class Flask(_PackageBoundObject): #: .. versionadded:: 0.9 self.url_build_error_handlers = [] - #: A dictionary with lists of functions that should be called at the - #: beginning of the request. The key of the dictionary is the name of - #: the blueprint this function is active for, ``None`` for all requests. - #: This can for example be used to open database connections or - #: getting hold of the currently logged in user. To register a - #: function here, use the :meth:`before_request` decorator. + #: A dictionary with lists of functions that will be called at the + #: beginning of each request. The key of the dictionary is the name of + #: the blueprint this function is active for, or ``None`` for all + #: requests. To register a function, use the :meth:`before_request` + #: decorator. self.before_request_funcs = {} - #: A lists of functions that should be called at the beginning of the - #: first request to this instance. To register a function here, use - #: the :meth:`before_first_request` decorator. + #: A list of functions that will be called at the beginning of the + #: first request to this instance. To register a function, use the + #: :meth:`before_first_request` decorator. #: #: .. versionadded:: 0.8 self.before_first_request_funcs = [] @@ -457,12 +456,11 @@ class Flask(_PackageBoundObject): #: .. versionadded:: 0.9 self.teardown_appcontext_funcs = [] - #: A dictionary with lists of functions that can be used as URL - #: value processor functions. Whenever a URL is built these functions - #: are called to modify the dictionary of values in place. The key - #: ``None`` here is used for application wide - #: callbacks, otherwise the key is the name of the blueprint. - #: Each of these functions has the chance to modify the dictionary + #: A dictionary with lists of functions that are called before the + #: :attr:`before_request_funcs` functions. The key of the dictionary is + #: the name of the blueprint this function is active for, or ``None`` + #: for all requests. To register a function, use + #: :meth:`url_value_preprocessor`. #: #: .. versionadded:: 0.7 self.url_value_preprocessors = {} @@ -1314,11 +1312,13 @@ class Flask(_PackageBoundObject): @setupmethod def before_request(self, f): """Registers a function to run before each request. + + For example, this can be used to open a database connection, or to load + the logged in user from the session. - The function will be called without any arguments. - If the function returns a non-None value, it's handled as - if it was the return value from the view and further - request handling is stopped. + The function will be called without any arguments. If it returns a + non-None value, the value is handled as if it was the return value from + the view, and further request handling is stopped. """ self.before_request_funcs.setdefault(None, []).append(f) return f @@ -1437,9 +1437,17 @@ class Flask(_PackageBoundObject): @setupmethod def url_value_preprocessor(self, f): - """Registers a function as URL value preprocessor for all view - functions of the application. It's called before the view functions - are called and can modify the url values provided. + """Register a URL value preprocessor function for all view + functions in the application. These functions will be called before the + :meth:`before_request` functions. + + The function can modify the values captured from the matched url before + they are passed to the view. For example, this can be used to pop a + common language code value and place it in ``g`` rather than pass it to + every view. + + The function is passed the endpoint name and values dict. The return + value is ignored. """ self.url_value_preprocessors.setdefault(None, []).append(f) return f @@ -1877,16 +1885,14 @@ class Flask(_PackageBoundObject): raise error def preprocess_request(self): - """Called before the request dispatching. - - Triggers two set of hook functions that should be invoked prior to request dispatching: - :attr:`url_value_preprocessors` and :attr:`before_request_funcs` - (the latter are functions decorated with :meth:`before_request` decorator). - In both cases, the method triggers only the functions that are either global - or registered to the current blueprint. - - If any function in :attr:`before_request_funcs` returns a value, it's handled as if it was - the return value from the view function, and further request handling is stopped. + """Called before the request is dispatched. Calls + :attr:`url_value_preprocessors` registered with the app and the + current blueprint (if any). Then calls :attr:`before_request_funcs` + registered with the app and the blueprint. + + If any :meth:`before_request` handler returns a non-None value, the + value is handled as if it was the return value from the view, and + further request handling is stopped. """ bp = _request_ctx_stack.top.request.blueprint