Reference

This section is generated from the source code with mkdocstrings. It collects the package entry point and each module in one place so students can see both package-level and module-level documentation together.

Application factory for the Flask tutorial project.

create_app(test_config=None)

Create and configure the Flask application.

The factory loads default settings from :mod:flaskr.settings, applies any environment-specific overrides, and then wires up the database session and blueprints used by the tutorial app.

Parameters:

Name	Type	Description	Default
test_config	Mapping[str, Any] | None	Optional configuration values that override the default settings. This is primarily used by tests.	None

Returns:

Type	Description
Flask	The configured Flask application instance.

Examples:

>>> app = create_app({"TESTING": True, "SECRET_KEY": "test"})
>>> app.config["TESTING"]
True

auth

Authentication views and helpers for the tutorial application.

register()

Register a new user account.

On GET requests this view renders the registration form. On POST requests it validates the submitted credentials, creates the user, and redirects to the login page when registration succeeds.

Returns:

Type	Description
ResponseReturnValue	The rendered registration page or a redirect to the login page.

login()

Authenticate an existing user and start a session.

Returns:

Type	Description
ResponseReturnValue	The rendered login form or a redirect to the blog index after a
ResponseReturnValue	successful login.

load_logged_in_user()

Load the current user from the session into flask.g.

This runs before every request so templates and view functions can access g.user without repeating the database lookup themselves.

login_required(view)

Require an authenticated user before executing a view function.

Parameters:

Name	Type	Description	Default
view	Callable[P, ResponseReturnValue]	View function to protect.	required

Returns:

Type	Description
Callable[P, ResponseReturnValue]	A wrapped view that redirects anonymous visitors to the login page.

Examples:

>>> @bp.route("/drafts")
... @login_required
... def drafts():
...     return "Only logged-in users can see this page."

Note

Place @login_required below @bp.route(...) so Flask registers the protected view function.

logout()

Clear the active session and return to the home page.

Returns:

Type	Description
ResponseReturnValue	A redirect to the blog index.

blog

Blog views for listing, creating, and editing posts.

index()

Show the blog home page with the newest posts first.

Returns:

Type	Description
ResponseReturnValue	The rendered index page.

create()

Create a new post for the logged-in user.

Returns:

Type	Description
ResponseReturnValue	The rendered creation form or a redirect to the index page after the
ResponseReturnValue	post is saved.

get_post(id)

Return a post and ensure the current user is allowed to edit it.

Parameters:

Name	Type	Description	Default
id	int	Identifier of the post to retrieve.	required

Returns:

Type	Description
Post	The requested post.

Raises:

Type	Description
NotFound	If no post exists with the given id.
Forbidden	If the current user is not the author of the post.

update(id)

Edit an existing post owned by the current user.

Parameters:

Name	Type	Description	Default
id	int	Identifier of the post to update.	required

Returns:

Type	Description
ResponseReturnValue	The rendered update form or a redirect to the index page after saving.

delete(id)

Delete a post owned by the current user.

Parameters:

Name	Type	Description	Default
id	int	Identifier of the post to delete.	required

Returns:

Type	Description
ResponseReturnValue	A redirect to the blog index.

db

Database utilities for configuring and accessing SQLAlchemy sessions.

create_db_session(database_url=None)

Create the scoped database session used by the application.

Parameters:

Name	Type	Description	Default
database_url	str | None	Database connection URL. When omitted, the local SQLite tutorial database is used.	None

Returns:

Type	Description
scoped_session[Session]	A tuple containing the scoped session registry and a callback that
Callable[[BaseException | None], None]	removes the active session at the end of a request.

init_db(database_url=DEFAULT_DATABASE_URL)

Recreate the database schema from the SQLAlchemy models.

Parameters:

Name	Type	Description	Default
database_url	str	Database connection URL to initialize.	DEFAULT_DATABASE_URL

Warning

This function drops existing tables before recreating them. Use it only for local development, tests, or other disposable databases.

get_db_session()

Return the request-scoped database session.

Returns:

Type	Description
scoped_session[Session]	The SQLAlchemy scoped session stored on the current Flask app.

Raises:

Type	Description
RuntimeError	If called outside an active Flask application context.

models

SQLAlchemy ORM models used by the tutorial blog application.

Base

Bases: DeclarativeBase

Base class shared by all ORM models in the project.

User

Bases: Base

Registered user account.

Users can author blog posts and authenticate with a stored password hash.

Post

Bases: Base

Blog post written by a :class:User.

Each post stores a title, body text, creation timestamp, and the author who wrote it.

settings

Default configuration values for the tutorial application.

These settings keep the example project runnable out of the box while still being easy to override in tests, local environment files, or deployment configuration.