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25 changes: 25 additions & 0 deletions app/__init__.py
Original file line number Diff line number Diff line change
@@ -1,7 +1,32 @@
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate
from dotenv import load_dotenv
import os

db = SQLAlchemy()
migrate = Migrate()
load_dotenv()

def create_app(test_config=None):
app = Flask(__name__)

app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False

if not test_config:
app.config['SQLALCHEMY_DATABASE_URI'] = os.environ.get(
"SQLALCHEMY_DATABASE_URI")
else:
app.config["TESTING"] = True
app.config["SQLALCHEMY_DATABASE_URI"] = os.environ.get(
"SQLALCHEMY_TEST_DATABASE_URI")

db.init_app(app)
migrate.init_app(app, db)
from app.models.planet import Planet

from .routes import planets_bp
app.register_blueprint(planets_bp)


return app
Empty file added app/models/__init__.py
Empty file.
7 changes: 7 additions & 0 deletions app/models/planet.py
Original file line number Diff line number Diff line change
@@ -0,0 +1,7 @@
from app import db


class Planet(db.Model):
id = db.Column(db.Integer, primary_key=True, autoincrement=True)
name = db.Column(db.String)
description = db.Column(db.String)

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Would be good to add the instance method to_dict and class method from_dict to this class, which will shorten up the code in your routes.

    def to_dict(self):
        return dict(
            id = self.id,
            name = self.name,
            description = self.description
        )

    @classmethod
    def from_dict(cls, planet_data):
        return cls(
            name = planet_data["name"],
            description = planet_data["description"]
        )

No problem if you don't have time to refactor here, but try implementing this for Task List.

77 changes: 76 additions & 1 deletion app/routes.py
Original file line number Diff line number Diff line change
@@ -1,2 +1,77 @@
from flask import Blueprint
from app import db
from app.models.planet import Planet
from flask import Blueprint, jsonify, abort, make_response, request, Response

planets_bp = Blueprint("planets", __name__, url_prefix="/planets")

@planets_bp.route("", methods=["GET", "POST"])

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Prefer that GET and POST are separate routes

def handle_planets():
if request.method == "GET":

name_query = request.args.get("name")
if name_query:
planets = Planet.query.filter_by(name=name_query)
else:
planets = Planet.query.all()

planets_response = []
for planet in planets:
planets_response.append({
"id": planet.id,
"name": planet.name,
"description": planet.description
})
Comment on lines +17 to +23

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This would be a good spot to try out list comprehension. You could create an instance method in the Planet class to_dict that turns an instance of planet into a dictionary representing a planet. We need to send back objects represented by dictionaries since our client doesn't understand python.

return jsonify(planets_response)

elif request.method == "POST":

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Older patterns for designing routes in Flask have shown a route that handles different REST methods and then uses if/elif to conditionally return the correct response. By separating the two request types out into their own methods, the code becomes more readable and each function has a single responsibility.

request_body = request.get_json()
new_planet = Planet(name=request_body["name"],
description=request_body["description"])
Comment on lines +27 to +29

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Would be good to add in some error handling here since request_body is the data that a client sends via the request body. We should assume that requests could have bad data, either missing keys or values or the keys could be misspelled.

If the request_body didn't have "name" but had "planet_name" then line 28 would throw an unhandled exception.


db.session.add(new_planet)
db.session.commit()

return make_response(jsonify(f"Planet {new_planet.name} successfully created"), 201)


def validate_planet(planet_id):
try:
planet_id = int(planet_id)
except:
abort(make_response({"message":f"planet {planet_id} invalid"}, 400))

planet = Planet.query.get(planet_id)

if not planet:
abort(make_response({"message":f"planet {planet_id} not found"}, 404))

return planet

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Looks good. Feel free to refer back to Flasky for how to make validate_planet into the more generic validate_model that can be used for more than one class. You'll need to implement something similar in Task List.



@planets_bp.route("/<planet_id>", methods=["GET", "PUT", "DELETE"])

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Prefer each request type to have their own function.

def handle_one_planet(planet_id):
planet = validate_planet(planet_id)

if request.method == "GET":
return {
"id": planet.id,
"name": planet.name,
"description": planet.description,
}

elif request.method == "PUT":
request_body = request.get_json()

planet.name = request_body["name"]
planet.description = request_body["description"]

db.session.commit()

return make_response(f"Planet #{planet.id} successfully updated")

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When we pass a string to make_response(), the datatype that gets sent back as a header in the response is HTML. However, your GET /planets and POST /planets routes return jsonify'd objects which have a datatype of JSON. Therefore, one API is sending a mix of HTML and JSON responses, which isn't ideal.

I know this is what was shown in Learn 😖. In the last reading from Part 6 Testing, there's mention of using jsonify like this:
return make_response(jsonify(f"Planet #{planet.id} successfully updated"))

Doing so changes the header data type from HTML to JSON. Making the changes in the DELETE requests would make your API only return JSON responses, which is good.

An even better way to go about this, I think, would be for your PUT and your POST requests to just return a dictionary representing the planet that was inserted into the DB or the planet that was updated in the DB. So for your PUT and your POST request you could return a response like:

return jsonify(planet.to_dict()), 201 # or whatever correct status code you want to pass in the response.


elif request.method == "DELETE":
db.session.delete(planet)
db.session.commit()

return make_response(f"Planet #{planet.id} successfully deleted")

1 change: 1 addition & 0 deletions migrations/README
Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
Generic single-database configuration.
45 changes: 45 additions & 0 deletions migrations/alembic.ini
Original file line number Diff line number Diff line change
@@ -0,0 +1,45 @@
# A generic, single database configuration.

[alembic]
# template used to generate migration files
# file_template = %%(rev)s_%%(slug)s

# set to 'true' to run the environment during
# the 'revision' command, regardless of autogenerate
# revision_environment = false


# Logging configuration
[loggers]
keys = root,sqlalchemy,alembic

[handlers]
keys = console

[formatters]
keys = generic

[logger_root]
level = WARN
handlers = console
qualname =

[logger_sqlalchemy]
level = WARN
handlers =
qualname = sqlalchemy.engine

[logger_alembic]
level = INFO
handlers =
qualname = alembic

[handler_console]
class = StreamHandler
args = (sys.stderr,)
level = NOTSET
formatter = generic

[formatter_generic]
format = %(levelname)-5.5s [%(name)s] %(message)s
datefmt = %H:%M:%S
96 changes: 96 additions & 0 deletions migrations/env.py
Original file line number Diff line number Diff line change
@@ -0,0 +1,96 @@
from __future__ import with_statement

import logging
from logging.config import fileConfig

from sqlalchemy import engine_from_config
from sqlalchemy import pool
from flask import current_app

from alembic import context

# this is the Alembic Config object, which provides
# access to the values within the .ini file in use.
config = context.config

# Interpret the config file for Python logging.
# This line sets up loggers basically.
fileConfig(config.config_file_name)
logger = logging.getLogger('alembic.env')

# add your model's MetaData object here
# for 'autogenerate' support
# from myapp import mymodel
# target_metadata = mymodel.Base.metadata
config.set_main_option(
'sqlalchemy.url',
str(current_app.extensions['migrate'].db.engine.url).replace('%', '%%'))
target_metadata = current_app.extensions['migrate'].db.metadata

# other values from the config, defined by the needs of env.py,
# can be acquired:
# my_important_option = config.get_main_option("my_important_option")
# ... etc.


def run_migrations_offline():
"""Run migrations in 'offline' mode.

This configures the context with just a URL
and not an Engine, though an Engine is acceptable
here as well. By skipping the Engine creation
we don't even need a DBAPI to be available.

Calls to context.execute() here emit the given string to the
script output.

"""
url = config.get_main_option("sqlalchemy.url")
context.configure(
url=url, target_metadata=target_metadata, literal_binds=True
)

with context.begin_transaction():
context.run_migrations()


def run_migrations_online():
"""Run migrations in 'online' mode.

In this scenario we need to create an Engine
and associate a connection with the context.

"""

# this callback is used to prevent an auto-migration from being generated
# when there are no changes to the schema
# reference: http://alembic.zzzcomputing.com/en/latest/cookbook.html
def process_revision_directives(context, revision, directives):
if getattr(config.cmd_opts, 'autogenerate', False):
script = directives[0]
if script.upgrade_ops.is_empty():
directives[:] = []
logger.info('No changes in schema detected.')

connectable = engine_from_config(
config.get_section(config.config_ini_section),
prefix='sqlalchemy.',
poolclass=pool.NullPool,
)

with connectable.connect() as connection:
context.configure(
connection=connection,
target_metadata=target_metadata,
process_revision_directives=process_revision_directives,
**current_app.extensions['migrate'].configure_args
)

with context.begin_transaction():
context.run_migrations()


if context.is_offline_mode():
run_migrations_offline()
else:
run_migrations_online()
24 changes: 24 additions & 0 deletions migrations/script.py.mako
Original file line number Diff line number Diff line change
@@ -0,0 +1,24 @@
"""${message}

Revision ID: ${up_revision}
Revises: ${down_revision | comma,n}
Create Date: ${create_date}

"""
from alembic import op
import sqlalchemy as sa
${imports if imports else ""}

# revision identifiers, used by Alembic.
revision = ${repr(up_revision)}
down_revision = ${repr(down_revision)}
branch_labels = ${repr(branch_labels)}
depends_on = ${repr(depends_on)}


def upgrade():
${upgrades if upgrades else "pass"}


def downgrade():
${downgrades if downgrades else "pass"}
33 changes: 33 additions & 0 deletions migrations/versions/a91d71893aa5_adds_planet_model.py
Original file line number Diff line number Diff line change
@@ -0,0 +1,33 @@
"""adds Planet model

Revision ID: a91d71893aa5
Revises:
Create Date: 2023-05-02 17:28:23.061054

"""
from alembic import op
import sqlalchemy as sa


# revision identifiers, used by Alembic.
revision = 'a91d71893aa5'
down_revision = None
branch_labels = None
depends_on = None


def upgrade():
# ### commands auto generated by Alembic - please adjust! ###
op.create_table('planet',
sa.Column('id', sa.Integer(), autoincrement=True, nullable=False),
sa.Column('name', sa.String(), nullable=True),
sa.Column('description', sa.String(), nullable=True),
sa.PrimaryKeyConstraint('id')
)
# ### end Alembic commands ###


def downgrade():
# ### commands auto generated by Alembic - please adjust! ###
op.drop_table('planet')
# ### end Alembic commands ###
Empty file added tests/__init__.py
Empty file.
38 changes: 38 additions & 0 deletions tests/conftest.py
Original file line number Diff line number Diff line change
@@ -0,0 +1,38 @@
import pytest
from app import create_app
from app import db
from flask.signals import request_finished
from app.models.planet import Planet

@pytest.fixture
def app():
app = create_app({"TESTING": True})

@request_finished.connect_via(app)
def expire_session(sender, response, **extra):
db.session.remove()

with app.app_context():
db.create_all()
yield app

with app.app_context():
db.drop_all()


@pytest.fixture
def client(app):
return app.test_client()


@pytest.fixture
def two_saved_planets(app):
# Arrange
planet_mars = Planet(name="Mars",
description="Smallest planet")
planet_jupiter = Planet(name="Jupiter",
description="Largest planet")

db.session.add_all([planet_mars, planet_jupiter])

db.session.commit()

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I know that the Learn reading has a two_saved_books that looks like this. It creates two objects, adds them and commits to the DB. It would be nice if this fixture (while not shown in Learn) actually returns the objects it creates so that you can use them for comparison in your unit tests, like this and this

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