src/higher_lower/presentation/lectures/step_02_url_paths.py

@@ -4,31 +4,29 @@
 converter.
 """
 
-from flask import Flask
+from flask import Blueprint, Flask
 from markupsafe import escape
 
 from higher_lower.constants import HOST, PORT
 
+## Blueprint that holds the views of this lecture step.
+_blueprint = Blueprint("step_02_url_paths", __name__)
 
-def create_app() -> Flask:
-    """Build the Flask application of this lecture step.
 
-    @return The configured Flask application.
-    """
-    app = Flask(__name__)
-
-    @app.route("/")
-    def home() -> str:
+@_blueprint.route("/")
+def home() -> str:
     """Answer the home route."""
     return "Hello, World!"
 
-    @app.route("/bye")
-    def say_bye() -> str:
+
+@_blueprint.route("/bye")
+def say_bye() -> str:
     """Answer the fixed route /bye."""
     return "Bye"
 
-    @app.route("/username/<name>")
-    def greet(name: str) -> str:
+
+@_blueprint.route("/username/<name>")
+def greet(name: str) -> str:
     """Greet the user whose name is the variable section of the URL.
 
     @param name The text found in the URL after /username/.
@@ -36,8 +34,9 @@ def create_app() -> Flask:
     """
     return f"Hello there {escape(name)}!"
 
-    @app.route("/username/<name>/<int:number>")
-    def greet_with_number(name: str, number: int) -> str:
+
+@_blueprint.route("/username/<name>/<int:number>")
+def greet_with_number(name: str, number: int) -> str:
     """Greet the user and use the converter <int:number> for a number.
 
     @param name The text found in the URL after /username/.
@@ -46,6 +45,14 @@ def create_app() -> Flask:
     """
     return f"Hello there {escape(name)}, you are {number} years old!"
 
+
+def create_app() -> Flask:
+    """Build the Flask application of this lecture step.
+
+    @return The configured Flask application.
+    """
+    app = Flask(__name__)
+    app.register_blueprint(_blueprint)
     return app
 
 

src/higher_lower/presentation/lectures/step_03_html.py

@@ -3,7 +3,7 @@
 @brief A route that returns a heading, a paragraph and two images as HTML.
 """
 
-from flask import Flask
+from flask import Blueprint, Flask
 
 from higher_lower.constants import HOST, LECTURE_IMAGE_WIDTH, PORT, STILL_IMAGE
 
@@ -11,15 +11,12 @@ from higher_lower.constants import HOST, LECTURE_IMAGE_WIDTH, PORT, STILL_IMAGE
 ANIMATED_IMAGE: str = STILL_IMAGE.replace("_s.gif", ".gif")
 
 
-def create_app() -> Flask:
-    """Build the Flask application of this lecture step.
+## Blueprint that holds the views of this lecture step.
+_blueprint = Blueprint("step_03_html", __name__)
 
-    @return The configured Flask application.
-    """
-    app = Flask(__name__)
 
-    @app.route("/")
-    def home() -> str:
+@_blueprint.route("/")
+def home() -> str:
     """Return structured HTML instead of a plain string.
 
     The Python string uses double quotes and the HTML attributes use single
@@ -34,6 +31,14 @@ def create_app() -> Flask:
         f"<img src='{ANIMATED_IMAGE}' width={LECTURE_IMAGE_WIDTH}>"
     )
 
+
+def create_app() -> Flask:
+    """Build the Flask application of this lecture step.
+
+    @return The configured Flask application.
+    """
+    app = Flask(__name__)
+    app.register_blueprint(_blueprint)
     return app
 
 

src/higher_lower/presentation/lectures/step_04_decorators.py

@@ -7,7 +7,7 @@ the /bye route.
 from collections.abc import Callable
 from functools import wraps
 
-from flask import Flask
+from flask import Blueprint, Flask
 
 from higher_lower.constants import HOST, PORT
 
@@ -54,26 +54,32 @@ def make_underlined(function: Callable[..., str]) -> Callable[..., str]:
     return _wrap_in_tag(function, "u")
 
 
+## Blueprint that holds the views of this lecture step.
+_blueprint = Blueprint("step_04_decorators", __name__)
+
+
+@_blueprint.route("/")
+def home() -> str:
+    """Answer the home route."""
+    return "Hello, World!"
+
+
+@_blueprint.route("/bye")
+@make_bold
+@make_emphasis
+@make_underlined
+def say_bye() -> str:
+    """Answer /bye with bold, emphasised and underlined text."""
+    return "Bye"
+
+
 def create_app() -> Flask:
     """Build the Flask application of this lecture step.
 
     @return The configured Flask application.
     """
     app = Flask(__name__)
-
-    @app.route("/")
-    def home() -> str:
-        """Answer the home route."""
-        return "Hello, World!"
-
-    @app.route("/bye")
-    @make_bold
-    @make_emphasis
-    @make_underlined
-    def say_bye() -> str:
-        """Answer /bye with bold, emphasised and underlined text."""
-        return "Bye"
-
+    app.register_blueprint(_blueprint)
     return app
 
 

src/higher_lower/presentation/lectures/step_05_authenticated.py

@@ -7,7 +7,7 @@ only for a logged-in user.
 from collections.abc import Callable
 from functools import wraps
 
-from flask import Flask
+from flask import Blueprint, Flask
 from markupsafe import escape
 
 from higher_lower.constants import HOST, PORT
@@ -57,15 +57,12 @@ def create_blog_post(user: User) -> str:
     return f"This is {user.name}'s new blog post."
 
 
-def create_app() -> Flask:
-    """Build the Flask application of this lecture step.
+## Blueprint that holds the views of this lecture step.
+_blueprint = Blueprint("step_05_authenticated", __name__)
 
-    @return The configured Flask application.
-    """
-    app = Flask(__name__)
 
-    @app.route("/")
-    def home() -> str:
+@_blueprint.route("/")
+def home() -> str:
     """Show the result of create_blog_post for a user in and out."""
     lines = []
     for name, logged_in in (("Angela", True), ("Bob", False)):
@@ -79,6 +76,14 @@ def create_app() -> Flask:
         )
     return "<h1>is_authenticated</h1>" + "".join(lines)
 
+
+def create_app() -> Flask:
+    """Build the Flask application of this lecture step.
+
+    @return The configured Flask application.
+    """
+    app = Flask(__name__)
+    app.register_blueprint(_blueprint)
     return app