def get_post(id, check_author=True):
"""Get a post and its author by id.
Checks that the id exists and optionally that the current user is
the author.
:param id: id of post to get
:param check_author: require the current user to be the author
:return: the post with author information
:raise 404: if a post with the given id doesn't exist
:raise 403: if the current user isn't the author
"""
post = (get_db().execute(
"SELECT p.id, title, body, created, author_id, username"
" FROM post p JOIN user u ON p.author_id = u.id"
" WHERE p.id = ?",
(id, ),
).fetchone())
if post is None:
abort(404, "Post id {0} doesn't exist.".format(id))
if check_author and post["author_id"] != g.user["id"]:
abort(403)
return post
def register():
"""Register a new user.
Validates that the username is not already taken. Hashes the
password for security.
"""
if request.method == "POST":
username = request.form["username"]
password = request.form["password"]
db = get_db()
error = None
if not username:
error = "Username is required."
elif not password:
error = "Password is required."
elif (db.execute("SELECT id FROM user WHERE username = ?",
(username, )).fetchone() is not None):
error = "User {0} is already registered.".format(username)
if error is None:
# the name is available, store it in the database and go to
# the login page
db.execute(
"INSERT INTO user (username, password) VALUES (?, ?)",
(username, generate_password_hash(password)),
)
db.commit()
return redirect(url_for("auth.login"))
flash(error)
return render_template("auth/register.html")
def load_logged_in_user():
"""If a user id is stored in the session, load the user object from
the database into ``g.user``."""
user_id = session.get("user_id")
if user_id is None:
g.user = None
else:
g.user = (get_db().execute("SELECT * FROM user WHERE id = ?",
(user_id, )).fetchone())
def delete(id):
"""Delete a post.
Ensures that the post exists and that the logged in user is the
author of the post.
"""
get_post(id)
db = get_db()
db.execute("DELETE FROM post WHERE id = ?", (id, ))
db.commit()
return redirect(url_for("blog.index"))
def update(id):
"""Update a post if the current user is the author."""
post = get_post(id)
if request.method == "POST":
title = request.form["title"]
body = request.form["body"]
error = None
if not title:
error = "Title is required."
if error is not None:
flash(error)
else:
db = get_db()
db.execute("UPDATE post SET title = ?, body = ? WHERE id = ?",
(title, body, id))
db.commit()
return redirect(url_for("blog.index"))
return render_template("blog/update.html", post=post)
def create():
"""Create a new post for the current user."""
if request.method == "POST":
title = request.form["title"]
body = request.form["body"]
error = None
if not title:
error = "Title is required."
if error is not None:
flash(error)
else:
db = get_db()
db.execute(
"INSERT INTO post (title, body, author_id) VALUES (?, ?, ?)",
(title, body, g.user["id"]),
)
db.commit()
return redirect(url_for("blog.index"))
return render_template("blog/create.html")
def login():
"""Log in a registered user by adding the user id to the session."""
if request.method == "POST":
username = request.form["username"]
password = request.form["password"]
db = get_db()
error = None
user = db.execute("SELECT * FROM user WHERE username = ?",
(username, )).fetchone()
if user is None:
error = "Incorrect username."
elif not check_password_hash(user["password"], password):
error = "Incorrect password."
if error is None:
# store the user id in a new session and return to the index
session.clear()
session["user_id"] = user["id"]
return redirect(url_for("index"))
flash(error)
return render_template("auth/login.html")
def index():
"""Show all the posts, most recent first."""
db = get_db()
posts = db.execute(sel).fetchall()
return render_template("blog/index.html", posts=posts)