Add chapter 7

.gitignore

@@ -20,3 +20,4 @@ Thumbs.db
 *venv*
 
 .flaskenv
+mail_config.sh

app/__init__.py

@@ -3,6 +3,10 @@
 from flask_sqlalchemy import SQLAlchemy
 from flask_migrate import Migrate
 from flask_login import LoginManager
+import logging
+from logging.handlers import SMTPHandler
+from logging.handlers import RotatingFileHandler
+import os
 
 app = Flask(__name__)
 login = LoginManager(app)
@@ -11,5 +15,38 @@
 db = SQLAlchemy(app)
 migrate = Migrate(app, db)  # Migrate is a wrapper around Alembic
 
+if not app.debug:
+    if app.config["MAIL_SERVER"]:
+        auth = None
+        secure = None
 
-from app import routes, models
+        if app.config["MAIL_USERNAME"] or app.config["MAIL_PASSWORD"]:
+            auth = (app.config["MAIL_USERNAME"], app.config["MAIL_PASSWORD"])
+        if app.config["MAIL_USE_TLS"]:
+            secure = ()
+        mail_handler = SMTPHandler(
+            mailhost=(app.config["MAIL_SERVER"], app.config["MAIL_PORT"]),
+            fromaddr="no-reply@" + app.config["MAIL_SERVER"],
+            toaddrs=app.config["ADMINS"],
+            subject="Microblog Failure",
+            credentials=auth,
+            secure=secure,
+        )
+        mail_handler.setLevel(logging.ERROR)
+        app.logger.addHandler(mail_handler)
+    if not os.path.exists("logs"):
+        os.mkdir("logs")
+    file_handler = RotatingFileHandler(
+        "logs/microblog.log", maxBytes=10240, backupCount=10
+    )
+    file_handler.setFormatter(
+        logging.Formatter(
+            "%(asctime)s %(levelname)s: %(message)s [in %(pathname)s:%(lineno)d]"
+        )
+    )
+    file_handler.setLevel(logging.INFO)
+    app.logger.addHandler(file_handler)
+    app.logger.setLevel(logging.INFO)
+    app.logger.info("Microblog startup")
+
+from app import routes, models, errors

app/config.py

@@ -9,3 +9,9 @@ class Config(object):
         "DATABASE_URL"
     ) or "sqlite:///" + os.path.join(basedir, "app.db")
     SQLALCHEMY_TRACK_MODIFICATIONS = False
+    MAIL_SERVER = os.environ.get("MAIL_SERVER")
+    MAIL_PORT = int(os.environ.get("MAIL_PORT") or 25)
+    MAIL_USE_TLS = os.environ.get("MAIL_USE_TLS") is not None
+    MAIL_USERNAME = os.environ.get("MAIL_USERNAME")
+    MAIL_PASSWORD = os.environ.get("MAIL_PASSWORD")
+    ADMINS = ["tiago.lubiana.alves@usp.br"]

app/errors.py

@@ -0,0 +1,13 @@
+from flask import render_template
+from app import app, db
+
+
+@app.errorhandler(404)
+def not_found_error(error):
+    return render_template("404.html"), 404
+
+
+@app.errorhandler(500)
+def internal_error(error):
+    db.session.rollback()
+    return render_template("500.html"), 500

app/forms.py

@@ -18,6 +18,16 @@ class EditProfileForm(FlaskForm):
     about_me = TextAreaField("About me", validators=[Length(min=0, max=140)])
     submit = SubmitField("Submit")
 
+    def __init__(self, original_username, *args, **kwargs):
+        super(EditProfileForm, self).__init__(*args, **kwargs)
+        self.original_username = original_username
+
+    def validate_username(self, username):
+        if username.data != self.original_username:
+            user = User.query.filter_by(username=self.username.data).first()
+            if user is not None:
+                raise ValidationError("Please use a different username.")
+
 
 class RegistrationForm(FlaskForm):
     username = StringField("Username", validators=[DataRequired()])

app/routes.py

@@ -20,7 +20,7 @@ def before_request():
 @app.route("/edit_profile", methods=["GET", "POST"])
 @login_required
 def edit_profile():
-    form = EditProfileForm()
+    form = EditProfileForm(current_user.username)
     if form.validate_on_submit():
         current_user.username = form.username.data
         current_user.about_me = form.about_me.data

app/templates/404.html

@@ -0,0 +1,5 @@
+{% extends "base.html" %}
+{% block content %}
+<h1>File Not Found</h1>
+<p><a href="{{ url_for('index') }}">Back</a></p>
+{% endblock %}

app/templates/500.html

@@ -0,0 +1,6 @@
+{% extends "base.html" %}
+{% block content %}
+<h1>An unexpected error has occurred</h1>
+<p>The administrator has been notified. Sorry for the inconvenience!</p>
+<p><a href="{{ url_for('index') }}">Back</a></p>
+{% endblock %}

logs/microblog.log

@@ -0,0 +1,75 @@
+2023-05-03 14:42:48,422 INFO: Microblog startup [in /home/lubianat/Documents/random/flask_tutorial/app/__init__.py:50]
+2023-05-03 14:43:04,661 ERROR: Exception on /edit_profile [POST] [in /home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/flask/app.py:1744]
+Traceback (most recent call last):
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/engine/base.py", line 1964, in _exec_single_context
+    self.dialect.do_execute(
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/engine/default.py", line 748, in do_execute
+    cursor.execute(statement, parameters)
+sqlite3.IntegrityError: UNIQUE constraint failed: user.username
+
+The above exception was the direct cause of the following exception:
+
+Traceback (most recent call last):
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/flask/app.py", line 2528, in wsgi_app
+    response = self.full_dispatch_request()
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/flask/app.py", line 1825, in full_dispatch_request
+    rv = self.handle_user_exception(e)
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/flask/app.py", line 1823, in full_dispatch_request
+    rv = self.dispatch_request()
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/flask/app.py", line 1799, in dispatch_request
+    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/flask_login/utils.py", line 290, in decorated_view
+    return current_app.ensure_sync(func)(*args, **kwargs)
+  File "/home/lubianat/Documents/random/flask_tutorial/app/routes.py", line 27, in edit_profile
+    db.session.commit()
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/orm/scoping.py", line 553, in commit
+    return self._proxied.commit()
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/orm/session.py", line 1903, in commit
+    trans.commit(_to_root=True)
+  File "<string>", line 2, in commit
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/orm/state_changes.py", line 137, in _go
+    ret_value = fn(self, *arg, **kw)
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/orm/session.py", line 1218, in commit
+    self._prepare_impl()
+  File "<string>", line 2, in _prepare_impl
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/orm/state_changes.py", line 137, in _go
+    ret_value = fn(self, *arg, **kw)
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/orm/session.py", line 1193, in _prepare_impl
+    self.session.flush()
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/orm/session.py", line 4155, in flush
+    self._flush(objects)
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/orm/session.py", line 4292, in _flush
+    transaction.rollback(_capture_exception=True)
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/util/langhelpers.py", line 147, in __exit__
+    raise exc_value.with_traceback(exc_tb)
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/orm/session.py", line 4252, in _flush
+    flush_context.execute()
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/orm/unitofwork.py", line 467, in execute
+    rec.execute(self)
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/orm/unitofwork.py", line 644, in execute
+    util.preloaded.orm_persistence.save_obj(
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/orm/persistence.py", line 85, in save_obj
+    _emit_update_statements(
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/orm/persistence.py", line 890, in _emit_update_statements
+    c = connection.execute(
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/engine/base.py", line 1414, in execute
+    return meth(
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/sql/elements.py", line 486, in _execute_on_connection
+    return connection._execute_clauseelement(
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/engine/base.py", line 1638, in _execute_clauseelement
+    ret = self._execute_context(
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/engine/base.py", line 1842, in _execute_context
+    return self._exec_single_context(
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/engine/base.py", line 1983, in _exec_single_context
+    self._handle_dbapi_exception(
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/engine/base.py", line 2326, in _handle_dbapi_exception
+    raise sqlalchemy_exception.with_traceback(exc_info[2]) from e
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/engine/base.py", line 1964, in _exec_single_context
+    self.dialect.do_execute(
+  File "/home/lubianat/Documents/random/flask_tutorial/venv/lib/python3.8/site-packages/sqlalchemy/engine/default.py", line 748, in do_execute
+    cursor.execute(statement, parameters)
+sqlalchemy.exc.IntegrityError: (sqlite3.IntegrityError) UNIQUE constraint failed: user.username
+[SQL: UPDATE user SET username=?, about_me=? WHERE user.id = ?]
+[parameters: ('susan', 'a', 2)]
+(Background on this error at: https://sqlalche.me/e/20/gkpj)
+2023-05-03 14:45:41,536 INFO: Microblog startup [in /home/lubianat/Documents/random/flask_tutorial/app/__init__.py:50]