flask.blueprints.Blueprint

class documentation

class Blueprint(Scaffold):

Represents a blueprint, a collection of routes and other app-related functions that can be registered on a real application later.

A blueprint is an object that allows defining application functions without requiring an application object ahead of time. It uses the same decorators as ~flask.Flask, but defers the need for an application by recording them for later registration.

Decorating a function with a blueprint creates a deferred function that is called with ~flask.blueprints.BlueprintSetupState when the blueprint is registered on an application.

See :doc:`/blueprints` for more information.

Changed in version 1.1.0: Blueprints have a cli group to register nested CLI commands. The cli_group parameter controls the name of the group under the flask command.

New in version 0.7.

Parameters
name	The name of the blueprint. Will be prepended to each endpoint name.
import_name	The name of the blueprint package, usually `__name__`. This helps locate the `root_path` for the blueprint.
static_folder	A folder with static files that should be served by the blueprint's static route. The path is relative to the blueprint's root path. Blueprint static files are disabled by default.
static_url_path	The url to serve static files from. Defaults to `static_folder`. If the blueprint does not have a `url_prefix`, the app's static route will take precedence, and the blueprint's static files won't be accessible.
template_folder	A folder with templates that should be added to the app's template search path. The path is relative to the blueprint's root path. Blueprint templates are disabled by default. Blueprint templates have a lower precedence than those in the app's templates folder.
url_prefix	A path to prepend to all of the blueprint's URLs, to make them distinct from the rest of the app's routes.
subdomain	A subdomain that blueprint routes will match on by default.
url_defaults	A dict of default values that blueprint routes will receive by default.
root_path	By default, the blueprint will automatically set this based on `import_name`. In certain situations this automatic detection can fail, so the path can be specified manually instead.

Method	`__init__`	Undocumented
Method	`_is_setup_finished`	Undocumented
Method	`add_app_template_filter`	Register a custom template filter, available application wide. Like `Flask.add_template_filter` but for a blueprint. Works exactly like the `app_template_filter` decorator.
Method	`add_app_template_global`	Register a custom template global, available application wide. Like `Flask.add_template_global` but for a blueprint. Works exactly like the `app_template_global` decorator.
Method	`add_app_template_test`	Register a custom template test, available application wide. Like `Flask.add_template_test` but for a blueprint. Works exactly like the `app_template_test` decorator.
Method	`add_url_rule`	Like `Flask.add_url_rule` but for a blueprint. The endpoint for the `url_for` function is prefixed with the name of the blueprint.
Method	`after_app_request`	Like `Flask.after_request` but for a blueprint. Such a function is executed after each request, even if outside of the blueprint.
Method	`app_context_processor`	Like `Flask.context_processor` but for a blueprint. Such a function is executed each request, even if outside of the blueprint.
Method	`app_errorhandler`	Like `Flask.errorhandler` but for a blueprint. This handler is used for all requests, even if outside of the blueprint.
Method	`app_template_filter`	Register a custom template filter, available application wide. Like `Flask.template_filter` but for a blueprint.
Method	`app_template_global`	Register a custom template global, available application wide. Like `Flask.template_global` but for a blueprint.
Method	`app_template_test`	Register a custom template test, available application wide. Like `Flask.template_test` but for a blueprint.
Method	`app_url_defaults`	Same as `url_defaults` but application wide.
Method	`app_url_value_preprocessor`	Same as `url_value_preprocessor` but application wide.
Method	`before_app_first_request`	Like `Flask.before_first_request`. Such a function is executed before the first request to the application.
Method	`before_app_request`	Like `Flask.before_request`. Such a function is executed before each request, even if outside of a blueprint.
Method	`make_setup_state`	Creates an instance of `~flask.blueprints.BlueprintSetupState` object that is later passed to the register callback functions. Subclasses can override this to return a subclass of the setup state.
Method	`record`	No summary
Method	`record_once`	No summary
Method	`register`	No summary
Method	`register_blueprint`	Register a `~flask.Blueprint` on this blueprint. Keyword arguments passed to this method will override the defaults set on the blueprint.
Method	`teardown_app_request`	Like `Flask.teardown_request` but for a blueprint. Such a function is executed when tearing down each request, even if outside of the blueprint.
Class Variable	`json_decoder`	Undocumented
Class Variable	`json_encoder`	Undocumented
Class Variable	`warn_on_modifications`	Undocumented
Instance Variable	`_blueprints`	Undocumented
Instance Variable	`_got_registered_once`	Undocumented
Instance Variable	`cli_group`	Undocumented
Instance Variable	`deferred_functions`	Undocumented
Instance Variable	`name`	Undocumented
Instance Variable	`subdomain`	Undocumented
Instance Variable	`url_prefix`	Undocumented
Instance Variable	`url_values_defaults`	Undocumented

Inherited from Scaffold:

Static Method	`_get_exc_class_and_code`	Get the exception class being handled. For HTTP status codes or `HTTPException` subclasses, return both the exception and status code.
Method	`__repr__`	Undocumented
Method	`_method_route`	Undocumented
Method	`after_request`	Register a function to run after each request to this object.
Method	`before_request`	Register a function to run before each request.
Method	`context_processor`	Registers a template context processor function.
Method	`delete`	Shortcut for `route` with `methods=["DELETE"]`.
Method	`endpoint`	Decorate a view function to register it for the given endpoint. Used if a rule is added without a `view_func` with `add_url_rule`.
Method	`errorhandler`	Register a function to handle errors by code or exception class.
Method	`get`	Shortcut for `route` with `methods=["GET"]`.
Method	`get_send_file_max_age`	Used by `send_file` to determine the `max_age` cache value for a given file path if it wasn't passed.
Method	`open_resource`	Open a resource file relative to `root_path` for reading.
Method	`patch`	Shortcut for `route` with `methods=["PATCH"]`.
Method	`post`	Shortcut for `route` with `methods=["POST"]`.
Method	`put`	Shortcut for `route` with `methods=["PUT"]`.
Method	`register_error_handler`	Alternative error attach function to the `errorhandler` decorator that is more straightforward to use for non decorator usage.
Method	`route`	Decorate a view function to register it with the given URL rule and options. Calls `add_url_rule`, which has more details about the implementation.
Method	`send_static_file`	No summary
Method	`static_folder.setter`	Undocumented
Method	`static_url_path.setter`	Undocumented
Method	`teardown_request`	No summary
Method	`url_defaults`	Callback function for URL defaults for all view functions of the application. It's called with the endpoint and values and should update the values passed in place.
Method	`url_value_preprocessor`	Register a URL value preprocessor function for all view functions in the application. These functions will be called before the `before_request` functions.
Instance Variable	`_static_folder`	Undocumented
Instance Variable	`_static_url_path`	Undocumented
Instance Variable	`after_request_funcs`	Undocumented
Instance Variable	`before_request_funcs`	Undocumented
Instance Variable	`cli`	Undocumented
Instance Variable	`error_handler_spec`	Undocumented
Instance Variable	`import_name`	Undocumented
Instance Variable	`root_path`	Undocumented
Instance Variable	`teardown_request_funcs`	Undocumented
Instance Variable	`template_context_processors`	Undocumented
Instance Variable	`template_folder`	Undocumented
Instance Variable	`url_default_functions`	Undocumented
Instance Variable	`url_value_preprocessors`	Undocumented
Instance Variable	`view_functions`	Undocumented
Property	`has_static_folder`	`True` if `static_folder` is set.
Property	`jinja_loader`	The Jinja loader for this object's templates. By default this is a class `jinja2.loaders.FileSystemLoader` to `template_folder` if it is set.
Property	`static_folder`	The absolute path to the configured static folder. `None` if no static folder is set.
Property	`static_url_path`	The URL prefix that the static route will be accessible from.

def __init__(self, name, import_name, static_folder=None, static_url_path=None, template_folder=None, url_prefix=None, subdomain=None, url_defaults=None, root_path=None, cli_group=_sentinel):

overrides flask.scaffold.Scaffold.__init__

Undocumented

Parameters
name:`str`	Undocumented
import_name:`str`	Undocumented
static_folder:`t.Optional[t.Union[str, os.PathLike]]`	Undocumented
static_url_path:`t.Optional[str]`	Undocumented
template_folder:`t.Optional[str]`	Undocumented
url_prefix:`t.Optional[str]`	Undocumented
subdomain:`t.Optional[str]`	Undocumented
url_defaults:`t.Optional[dict]`	Undocumented
root_path:`t.Optional[str]`	Undocumented
cli_group:`t.Optional[str]`	Undocumented

def _is_setup_finished(self):

overrides flask.scaffold.Scaffold._is_setup_finished

Undocumented

Returns
`bool`	Undocumented

def add_app_template_filter(self, f, name=None):

Register a custom template filter, available application wide. Like Flask.add_template_filter but for a blueprint. Works exactly like the app_template_filter decorator.

Parameters
f:`TemplateFilterCallable`	Undocumented
name:`t.Optional[str]`	the optional name of the filter, otherwise the function name will be used.

def add_app_template_global(self, f, name=None):

Register a custom template global, available application wide. Like Flask.add_template_global but for a blueprint. Works exactly like the app_template_global decorator.

New in version 0.10.

Parameters
f:`TemplateGlobalCallable`	Undocumented
name:`t.Optional[str]`	the optional name of the global, otherwise the function name will be used.

def add_app_template_test(self, f, name=None):

Register a custom template test, available application wide. Like Flask.add_template_test but for a blueprint. Works exactly like the app_template_test decorator.

New in version 0.10.

Parameters
f:`TemplateTestCallable`	Undocumented
name:`t.Optional[str]`	the optional name of the test, otherwise the function name will be used.

def add_url_rule(self, rule, endpoint=None, view_func=None, provide_automatic_options=None, **options):

overrides flask.scaffold.Scaffold.add_url_rule

Like Flask.add_url_rule but for a blueprint. The endpoint for the url_for function is prefixed with the name of the blueprint.

Parameters
rule:`str`	Undocumented
endpoint:`t.Optional[str]`	Undocumented
view_func:`t.Optional[t.Callable]`	Undocumented
provide_automatic_options:`t.Optional[bool]`	Undocumented
**options:`t.Any`	Undocumented

def after_app_request(self, f):

Like Flask.after_request but for a blueprint. Such a function is executed after each request, even if outside of the blueprint.

Parameters
f:`AfterRequestCallable`	Undocumented
Returns
`AfterRequestCallable`	Undocumented

def app_context_processor(self, f):

Like Flask.context_processor but for a blueprint. Such a function is executed each request, even if outside of the blueprint.

Parameters
f:`TemplateContextProcessorCallable`	Undocumented
Returns
`TemplateContextProcessorCallable`	Undocumented

def app_errorhandler(self, code):

Like Flask.errorhandler but for a blueprint. This handler is used for all requests, even if outside of the blueprint.

Parameters
code:`t.Union[t.Type[Exception], int]`	Undocumented
Returns
`t.Callable`	Undocumented

def app_template_filter(self, name=None):

Parameters
name:`t.Optional[str]`	the optional name of the filter, otherwise the function name will be used.
Returns
`t.Callable[[TemplateFilterCallable], TemplateFilterCallable]`	Undocumented

def app_template_global(self, name=None):

New in version 0.10.

Parameters
name:`t.Optional[str]`	the optional name of the global, otherwise the function name will be used.
Returns
`t.Callable[[TemplateGlobalCallable], TemplateGlobalCallable]`	Undocumented

def app_template_test(self, name=None):

New in version 0.10.

Parameters
name:`t.Optional[str]`	the optional name of the test, otherwise the function name will be used.
Returns
`t.Callable[[TemplateTestCallable], TemplateTestCallable]`	Undocumented

def app_url_defaults(self, f):

Same as url_defaults but application wide.

Parameters
f:`URLDefaultCallable`	Undocumented
Returns
`URLDefaultCallable`	Undocumented

def app_url_value_preprocessor(self, f):

Same as url_value_preprocessor but application wide.

Parameters
f:`URLValuePreprocessorCallable`	Undocumented
Returns
`URLValuePreprocessorCallable`	Undocumented

def before_app_first_request(self, f):

Like Flask.before_first_request. Such a function is executed before the first request to the application.

Parameters
f:`BeforeFirstRequestCallable`	Undocumented
Returns
`BeforeFirstRequestCallable`	Undocumented

def before_app_request(self, f):

Like Flask.before_request. Such a function is executed before each request, even if outside of a blueprint.

Parameters
f:`BeforeRequestCallable`	Undocumented
Returns
`BeforeRequestCallable`	Undocumented

def make_setup_state(self, app, options, first_registration=False):

Creates an instance of ~flask.blueprints.BlueprintSetupState object that is later passed to the register callback functions. Subclasses can override this to return a subclass of the setup state.

Parameters
app:`Flask`	Undocumented
options:`dict`	Undocumented
first_registration:`bool`	Undocumented
Returns
`BlueprintSetupState`	Undocumented

def record(self, func):

Registers a function that is called when the blueprint is registered on the application. This function is called with the state as argument as returned by the make_setup_state method.

Parameters
func:`t.Callable`	Undocumented

def record_once(self, func):

Works like record but wraps the function in another function that will ensure the function is only called once. If the blueprint is registered a second time on the application, the function passed is not called.

Parameters
func:`t.Callable`	Undocumented

def register(self, app, options):

Called by Flask.register_blueprint to register all views and callbacks registered on the blueprint with the application. Creates a .BlueprintSetupState and calls each record callback with it.

Changed in version 2.0.1: Nested blueprints are registered with their dotted name. This allows different blueprints with the same name to be nested at different locations.

Changed in version 2.0.1: The name option can be used to change the (pre-dotted) name the blueprint is registered with. This allows the same blueprint to be registered multiple times with unique names for url_for.

Changed in version 2.0.1: Registering the same blueprint with the same name multiple times is deprecated and will become an error in Flask 2.1.

Parameters
app:`Flask`	The application this blueprint is being registered with.
options:`dict`	Keyword arguments forwarded from `~Flask.register_blueprint`.

def register_blueprint(self, blueprint, **options):

Register a ~flask.Blueprint on this blueprint. Keyword arguments passed to this method will override the defaults set on the blueprint.

New in version 2.0.

Parameters
blueprint:`Blueprint`	Undocumented
**options:`t.Any`	Undocumented

def teardown_app_request(self, f):

Like Flask.teardown_request but for a blueprint. Such a function is executed when tearing down each request, even if outside of the blueprint.

Parameters
f:`TeardownCallable`	Undocumented
Returns
`TeardownCallable`	Undocumented

json_decoder =

overrides flask.scaffold.Scaffold.json_decoder

Undocumented

json_encoder =

overrides flask.scaffold.Scaffold.json_encoder

Undocumented

warn_on_modifications: bool =

Undocumented

_blueprints: t.List[t.Tuple[Blueprint, dict]] =

Undocumented

_got_registered_once: bool =

Undocumented

cli_group =

Undocumented

deferred_functions: t.List[DeferredSetupFunction] =

Undocumented

name =

overrides flask.scaffold.Scaffold.name

Undocumented

subdomain =

Undocumented

url_prefix =

Undocumented

url_values_defaults =

Undocumented