Exception handling for database queries

ref-test/app/__init__.py

@@ -1,11 +1,13 @@
 from .config import Production as Config
 from .models import User
 from .extensions import bootstrap, csrf, db, login_manager, mail
+from .tools.logs import write
 
 from flask import flash, Flask, render_template, request
-from flask.helpers import url_for
+from flask.helpers import abort, url_for
 from flask.json import jsonify
 from flask_wtf.csrf import CSRFError
+from sqlalchemy.exc import SQLAlchemyError
 from werkzeug.middleware.proxy_fix import ProxyFix
 
 from datetime import datetime
@@ -24,7 +26,10 @@ def create_app():
     login_manager.login_view = 'admin._login'
     @login_manager.user_loader
     def _load_user(id):
-        return User.query.filter_by(id=id).first()
+        try: return User.query.filter_by(id=id).first()
+        except SQLAlchemyError as exception:
+            write('system.log', f'Database error when loading user fo login manager: {exception}')
+            return abort(500)
 
     @app.before_request
     def _check_cookie_consent():

ref-test/app/admin/views.py

@@ -1,13 +1,15 @@
 from ..forms.admin import AddTimeAdjustment, CreateTest, CreateUser, DeleteUser, Login, Register, ResetPassword, UpdatePassword, UpdateUser, UploadData
 from ..models import Dataset, Entry, Test, User
 from ..tools.auth import disable_if_logged_in, require_account_creation
-from ..tools.forms import get_dataset_choices, get_time_options, send_errors_to_client
 from ..tools.data import check_dataset_exists, check_is_json, validate_json
+from ..tools.forms import get_dataset_choices, get_time_options, send_errors_to_client
+from ..tools.logs import write
 from ..tools.test import  answer_options, get_correct_answers
 
-from flask import abort, Blueprint, jsonify, render_template, redirect, request, send_file, session
+from flask import abort, Blueprint, jsonify, render_template, request, send_file, session
-from flask.helpers import flash, url_for
+from flask.helpers import abort, flash, redirect, url_for
 from flask_login import current_user, login_required
+from sqlalchemy.exc import SQLAlchemyError
 
 from datetime import date, datetime, timedelta
 from json import loads
@@ -26,8 +28,12 @@ admin = Blueprint(
 @admin.route('/dashboard/')
 @login_required
 def _home():
+    try:
         tests = Test.query.all()
         results = Entry.query.all()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     current_tests = [ test for test in tests if test.end_date >= datetime.now() and test.start_date.date() <= date.today() ]
     current_tests.sort(key= lambda x: x.end_date, reverse=True)
     upcoming_tests = [ test for test in tests if test.start_date.date() > datetime.now().date()]
@@ -39,8 +45,12 @@ def _home():
 @admin.route('/settings/')
 @login_required
 def _settings():
+    try:
         users = User.query.all()
         datasets = Dataset.query.all()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     return render_template('/admin/settings/index.html', users=users, datasets=datasets)
 
 @admin.route('/login/', methods=['GET','POST'])
@@ -50,7 +60,10 @@ def _login():
     form = Login()
     if request.method == 'POST':
         if form.validate_on_submit():
-            users = User.query.all()
+            try: users = User.query.all()
+            except SQLAlchemyError as exception:
+                write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+                return abort(500)
             user = None
             for _user in users:
                 if _user.get_username() == request.form.get('username').lower():
@@ -99,7 +112,10 @@ def _reset():
     if request.method == 'POST':
         if form.validate_on_submit():
             user = None
-            users = User.query.all()
+            try: users = User.query.all()
+            except SQLAlchemyError as exception:
+                write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+                return abort(500)
             for _user in users:
                 if _user.get_username() == request.form.get('username'):
                     user = _user
@@ -111,7 +127,10 @@ def _reset():
     
     token = request.args.get('token')
     if token:
-        user = User.query.filter_by(reset_token=token).first()
+        try: user = User.query.filter_by(reset_token=token).first()
+        except SQLAlchemyError as exception:
+            write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+            return abort(500)
         if not user: return redirect(url_for('admin._reset'))
         verification_token = user.verification_token
         user.clear_reset_tokens()
@@ -128,7 +147,10 @@ def _update_password():
     form = UpdatePassword()
     if form.validate_on_submit():
         user = session.pop('user')
-        user = User.query.filter_by(id=user).first()
+        try: user = User.query.filter_by(id=user).first()
+        except SQLAlchemyError as exception:
+            write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+            return abort(500)
         user.update(password=request.form.get('password'))
         session['remembered_username'] = user.get_username()
         flash('Your password has been reset.', 'success')
@@ -139,7 +161,10 @@ def _update_password():
 @login_required
 def _users():
     form = CreateUser()
-    users = User.query.all()
+    try: users = User.query.all()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     if request.method == 'POST':
         if form.validate_on_submit():
             password = request.form.get('password')
@@ -156,7 +181,10 @@ def _users():
 @admin.route('/settings/users/delete/<string:id>', methods=['GET', 'POST'])
 @login_required
 def _delete_user(id:str):
-    user = User.query.filter_by(id=id).first()
+    try: user = User.query.filter_by(id=id).first()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     form = DeleteUser()
     if request.method == 'POST': 
         if not user: return jsonify({'error': 'User does not exist.'}), 400
@@ -180,7 +208,10 @@ def _delete_user(id:str):
 @admin.route('/settings/users/update/<string:id>', methods=['GET', 'POST'])
 @login_required
 def _update_user(id:str):
-    user = User.query.filter_by(id=id).first()
+    try: user = User.query.filter_by(id=id).first()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     form = UpdateUser()
     if request.method == 'POST': 
         if not user: return jsonify({'error': 'User does not exist.'}), 400
@@ -222,7 +253,10 @@ def _questions():
             return jsonify({'error': message}), 400
         return send_errors_to_client(form=form)
 
-    data = Dataset.query.all()
+    try: data = Dataset.query.all()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     return render_template('/admin/settings/questions.html', form=form, data=data)
 
 @admin.route('/settings/questions/delete/', methods=['POST'])
@@ -231,7 +265,10 @@ def _edit_questions():
     id = request.get_json()['id']
     action = request.get_json()['action']
     if not action == 'delete': return jsonify({'error': 'Invalid action.'}), 400
-    dataset = Dataset.query.filter_by(id=id).first()
+    try: dataset = Dataset.query.filter_by(id=id).first()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     if action == 'delete': success, message = dataset.delete()
     if success: return jsonify({'success': message}), 200
     return jsonify({'error': message}), 400
@@ -239,7 +276,10 @@ def _edit_questions():
 @admin.route('/settings/questions/download/<string:id>/')
 @login_required
 def _download(id:str):
-    dataset = Dataset.query.filter_by(id=id).first()
+    try: dataset = Dataset.query.filter_by(id=id).first()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     if not dataset: return abort(404)
     data_path = path.abspath(dataset.get_file())
     return send_file(data_path, as_attachment=True, attachment_filename=f'{dataset.get_name()}.json')
@@ -250,7 +290,10 @@ def _download(id:str):
 @check_dataset_exists
 def _tests(filter:str=None):
     tests = None
-    _tests = Test.query.all()
+    try: _tests = Test.query.all()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     form = None
     now = datetime.now()
     if filter not in ['create','active','scheduled','expired','all']: return redirect(url_for('admin._tests', filter='active'))
@@ -296,7 +339,10 @@ def _create_test():
         new_test.end_date = datetime.strptime(new_test.end_date, '%Y-%m-%dT%H:%M')
         new_test.time_limit = None if request.form.get('time_limit') == 'none' else int(request.form.get('time_limit'))
         dataset = request.form.get('dataset')
-        new_test.dataset = Dataset.query.filter_by(id=dataset).first()
+        try: new_test.dataset = Dataset.query.filter_by(id=dataset).first()
+        except SQLAlchemyError as exception:
+            write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+            return abort(500)
         success, message = new_test.create()
         if success:
             flash(message=message, category='success')
@@ -310,7 +356,10 @@ def _edit_test():
     id = request.get_json()['id']
     action = request.get_json()['action']
     if action not in ['start', 'delete', 'end']: return jsonify({'error': 'Invalid action.'}), 400
-    test = Test.query.filter_by(id=id).first()
+    try: test = Test.query.filter_by(id=id).first()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     if not test: return jsonify({'error': 'Could not find the corresponding test to delete.'}), 404
     if action == 'delete': success, message = test.delete()
     if action == 'start': success, message = test.start()
@@ -324,7 +373,10 @@ def _edit_test():
 @login_required
 def _view_test(id:str=None):    
     form = AddTimeAdjustment()
-    test = Test.query.filter_by(id=id).first()
+    try: test = Test.query.filter_by(id=id).first()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     if request.method == 'POST':
         if not test: return jsonify({'error': 'Invalid test ID.'}), 404
         if form.validate_on_submit():
@@ -341,7 +393,10 @@ def _view_test(id:str=None):
 @admin.route('/test/<string:id>/delete-adjustment/', methods=['POST'])
 @login_required
 def _delete_adjustment(id:str=None):
-    test = Test.query.filter_by(id=id).first()
+    try: test = Test.query.filter_by(id=id).first()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     if not test: return jsonify({'error': 'Invalid test ID.'}), 404
     user_code = request.get_json()['user_code'].lower()
     success, message = test.remove_adjustment(user_code)
@@ -351,13 +406,19 @@ def _delete_adjustment(id:str=None):
 @admin.route('/results/')
 @login_required
 def _view_entries():
-    entries = Entry.query.all()
+    try: entries = Entry.query.all()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     return render_template('/admin/results.html', entries = entries)
 
 @admin.route('/results/<string:id>/', methods = ['GET', 'POST'])
 @login_required
 def _view_entry(id:str=None):
-    entry = Entry.query.filter_by(id=id).first()
+    try: entry = Entry.query.filter_by(id=id).first()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     if request.method == 'POST':
         if not entry: return jsonify({'error': 'Invalid entry ID.'}), 404
         action = request.get_json()['action']
@@ -388,6 +449,9 @@ def _view_entry(id:str=None):
 def _generate_certificate():
     from ..extensions import db
     id = request.get_json()['id']
-    entry = Entry.query.filter_by(id=id).first()
+    try: entry = Entry.query.filter_by(id=id).first()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     if not entry: return jsonify({'error': 'Invalid entry ID.'}), 404
     return render_template('/admin/components/certificate.html', entry = entry)

ref-test/app/api/views.py

@@ -1,9 +1,12 @@
 from ..models import Dataset, Entry, User
 from ..tools.data import validate_json
+from ..tools.logs import write
 from ..tools.test import evaluate_answers, generate_questions
 
-from flask import Blueprint, flash, jsonify, request, url_for
+from flask import Blueprint, jsonify, request
+from flask.helpers import abort, flash, url_for
 from flask_login import login_required
+from sqlalchemy.exc import SQLAlchemyError
 
 from datetime import datetime, timedelta
 from json import loads
@@ -16,7 +19,10 @@ api = Blueprint(
 @api.route('/questions/', methods=['POST'])
 def _fetch_questions():
     id = request.get_json()['id']
-    entry = Entry.query.filter_by(id=id).first()
+    try: entry = Entry.query.filter_by(id=id).first()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     if not entry: return jsonify({'error': 'Invalid entry ID.'}), 400
     test = entry.test
     user_code = entry.user_code
@@ -50,7 +56,10 @@ def _fetch_questions():
 def _submit_quiz():
     id = request.get_json()['id']
     answers = request.get_json()['answers']
-    entry = Entry.query.filter_by(id=id).first()
+    try: entry = Entry.query.filter_by(id=id).first()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     if not entry: return jsonify({'error': 'Unrecognised Entry.'}), 400
     test = entry.test
     dataset = test.dataset
@@ -71,7 +80,12 @@ def _submit_quiz():
 def _editor(id:str=None):
     request_data = request.get_json()
     id = request_data['id']
+    try:
         dataset = Dataset.query.filter_by(id=id).first()
+        user = User.query.filter_by(id=creator).first()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     if not dataset: return jsonify({'error': 'Invalid request. Dataset not found.'}), 404
     data_path = dataset.get_file()
     if request_data['action'] == 'fetch':
@@ -83,7 +97,6 @@ def _editor(id:str=None):
     name = request_data['name']
     data = request_data['data']
     if not validate_json(data): return jsonify({'error': 'The data you submitted was invalid.'}), 400
-    user = User.query.filter_by(id=creator).first()
     dataset.set_name(name)
     dataset.creator = user
     success, message = dataset.update(data=data, default=default)

ref-test/app/editor/views.py

@@ -1,11 +1,13 @@
 from ..forms.admin import EditDataset
 from ..models import Dataset, User
-from ..tools.forms import get_dataset_choices, send_errors_to_client
 from ..tools.data import check_dataset_exists
+from ..tools.forms import get_dataset_choices, send_errors_to_client
+from ..tools.logs import write
 
-from flask import Blueprint, flash, jsonify, redirect, render_template, request
+from flask import Blueprint, jsonify, render_template
-from flask.helpers import url_for
+from flask.helpers import abort, flash, redirect, request, url_for
 from flask_login import login_required
+from sqlalchemy.exc import SQLAlchemyError
 
 editor = Blueprint(
     name='editor',
@@ -31,9 +33,13 @@ def _editor():
 @check_dataset_exists
 @login_required
 def _editor_console(id:str=None):
+    try:
         dataset = Dataset.query.filter_by(id=id).first()
         datasets = Dataset.query.count()
         users = User.query.all()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     if not dataset:
         flash('Invalid dataset ID.', 'error')
         return redirect(url_for('admin._questions'))

ref-test/app/models/dataset.py

@@ -2,8 +2,8 @@ from ..extensions import db
 from ..tools.encryption import decrypt, encrypt
 from ..tools.logs import write
 
-from flask import flash
 from flask import current_app as app
+from flask.helpers import flash
 from flask_login import current_user
 from sqlalchemy.exc import SQLAlchemyError
 from werkzeug.utils import secure_filename
@@ -43,11 +43,13 @@ class Dataset(db.Model):
     def get_name(self): return decrypt(self.name)
 
     def make_default(self):
-        for dataset in Dataset.query.all():
-            dataset.default = False
-        self.default = True
         try:
-            db.session.commit()
+            for dataset in Dataset.query.all(): dataset.default = False
+        except SQLAlchemyError as exception:
+            write('system.log', f'Database error when setting default dataset {self.id}: {exception}')
+            return False, f'Database error {exception}.'
+        self.default = True
+        try: db.session.commit()
         except SQLAlchemyError as exception:
             db.session.rollback()
             write('system.log', f'Database error when setting default dataset {self.id}: {exception}')
@@ -61,10 +63,14 @@ class Dataset(db.Model):
             message = 'Cannot delete the default dataset.'
             flash(message, 'error')
             return False, message
+        try:
             if Dataset.query.count() == 1:
                 message = 'Cannot delete the only dataset.'
                 flash(message, 'error')
                 return False, message
+        except SQLAlchemyError as exception:
+            write('system.log', f'Database error when setting default dataset {self.id}: {exception}')
+            return False, f'Database error {exception}.'
         write('system.log', f'Dataset {self.id} deleted by {current_user.get_username()}.')
         filename = secure_filename('.'.join([self.id,'json']))
         data = Path(app.config.get('DATA'))

ref-test/app/models/entry.py

@@ -84,8 +84,7 @@ class Entry(db.Model):
     def start(self):
         self.start_time = datetime.now()
         self.status = 'started'
-        try:
+        try: db.session.commit()
-            db.session.commit()
         except SQLAlchemyError as exception:
             db.session.rollback()
             write('system.log', f'Database error when starting test for {self.get_surname()}, {self.get_first_name()}: {exception}')
@@ -104,8 +103,7 @@ class Entry(db.Model):
         else:
             self.status = 'late'
             self.valid = False
-        try:
+        try: db.session.commit()
-            db.session.commit()
         except SQLAlchemyError as exception:
             db.session.rollback()
             write('system.log', f'Database error when submitting entry for {self.get_surname()}, {self.get_first_name()}: {exception}')
@@ -118,8 +116,7 @@ class Entry(db.Model):
         if self.status == 'started': return False, 'The entry is still pending.'
         self.valid = True
         self.status = 'completed'
-        try:
+        try: db.session.commit()
-            db.session.commit()
         except SQLAlchemyError as exception:
             db.session.rollback()
             write('system.log', f'Database error when validating entry {self.id}: {exception}')
@@ -201,7 +198,6 @@ class Entry(db.Model):
             <p>Best wishes, <br/> SKA Refereeing</p>
             """
         )
-        try: 
+        try: mail.send(email)
-            mail.send(email)
         except SMTPException as exception:
             write('system.log', f'SMTP Error when trying to notify results to {self.get_surname()}, {self.get_first_name()} with error: {exception}')

ref-test/app/models/test.py

@@ -66,8 +66,7 @@ class Test(db.Model):
     def delete(self):
         if self.entries: return False, f'Cannot delete a test with submitted entries.'
         db.session.delete(self)
-        try:
+        try: db.session.commit()
-            db.session.commit()
         except SQLAlchemyError as exception:
             db.session.rollback()
             write('system.log', f'Database error when deleting test {self.get_code()}: {exception}')
@@ -79,8 +78,7 @@ class Test(db.Model):
         now = datetime.now()
         if self.start_date.date() > now.date():
             self.start_date = now
-            try:
+            try: db.session.commit()
-                db.session.commit()
             except SQLAlchemyError as exception:
                 db.session.rollback()
                 write('system.log', f'Database error when launching test {self.get_code()}: {exception}')
@@ -93,8 +91,7 @@ class Test(db.Model):
         now = datetime.now()
         if self.end_date >= now:
             self.end_date = now
-            try:
+            try: db.session.commit()
-                db.session.commit()
             except SQLAlchemyError as exception:
                 db.session.rollback()
                 write('system.log', f'Database error when closing test {self.get_code()}: {exception}')
@@ -108,8 +105,7 @@ class Test(db.Model):
         code = secrets.token_hex(3).lower()
         adjustments[code] = time
         self.adjustments = adjustments
-        try:
+        try: db.session.commit()
-            db.session.commit()
         except SQLAlchemyError as exception:
             db.session.rollback()
             write('system.log', f'Database error when adding adjustment to test {self.get_code()}: {exception}')
@@ -121,8 +117,7 @@ class Test(db.Model):
         if not self.adjustments: return False, f'There are no adjustments configured for test {self.get_code()}.'
         self.adjustments.pop(code)
         if not self.adjustments: self.adjustments = None
-        try:
+        try: db.session.commit()
-            db.session.commit()
         except SQLAlchemyError as exception:
             db.session.rollback()
             write('system.log', f'Database error when deleting adjustment from test {self.get_code()}: {exception}')
@@ -135,8 +130,7 @@ class Test(db.Model):
         if start_date: self.start_date = start_date
         if end_date: self.end_date = end_date
         if time_limit is not None: self.time_limit = time_limit
-        try:
+        try: db.session.commit()
-            db.session.commit()
         except SQLAlchemyError as exception:
             db.session.rollback()
             write('system.log', f'Database error when updating test {self.get_code()}: {exception}')

ref-test/app/models/user.py

@@ -2,8 +2,8 @@ from ..extensions import db, mail
 from ..tools.encryption import decrypt, encrypt
 from ..tools.logs import write
 
-from flask import flash, jsonify, session
+from flask import jsonify, session
-from flask.helpers import url_for
+from flask.helpers import flash, url_for
 from flask_login import current_user, login_user, logout_user, UserMixin
 from flask_mail import Message
 from smtplib import SMTPException
@@ -57,7 +57,10 @@ class User(UserMixin, db.Model):
 
     def register(self, notify:bool=False, password:str=None):
         self.generate_id()
-        users = User.query.all()
+        try: users = User.query.all()
+        except SQLAlchemyError as exception:
+            write('system.log', f'Database error when setting default dataset {self.id}: {exception}')
+            return False, f'Database error {exception}.'
         for user in users:
             if user.get_username() == self.get_username(): return False, f'Username {self.get_username()} already in use.'
             if user.get_email() == self.get_email(): return False, f'Email address {self.get_email()} already in use.'
@@ -97,8 +100,7 @@ class User(UserMixin, db.Model):
                 <p>SKA Refereeing</p>
                 """
             )
-            try:
+            try: mail.send(email)
-                mail.send(email)
             except SMTPException as exception:
                 write('system.log', f'SMTP Error while trying to notify new user account creation to {self.get_username()} with error: {exception}')
         return True, f'User {self.get_username()} was created successfully.'
@@ -151,14 +153,12 @@ class User(UserMixin, db.Model):
             <p>SKA Refereeing</p>
             """
         )
-        try:
+        try: mail.send(email)
-            mail.send(email)
         except SMTPException as exception:
             write('system.log', f'SMTP Error while trying to reset password for {self.get_username()} with error: {exception}')
             db.session.rollback()
             return jsonify({'error': f'SMTP Error: {exception}'}), 500
-        try:
+        try: db.session.commit()
-            db.session.commit()
         except SQLAlchemyError as exception:
             db.session.rollback()
             write('system.log', f'Database error when resetting password for user {self.get_username()}: {exception}')
@@ -167,8 +167,7 @@ class User(UserMixin, db.Model):
 
     def clear_reset_tokens(self):
         self.reset_token = self.verification_token = None
-        try:
+        try: db.session.commit()
-            db.session.commit()
         except SQLAlchemyError as exception:
             db.session.rollback()
             write('system.log', f'Database error when resetting clearing reset tokens for user {self.get_username()}: {exception}')
@@ -208,8 +207,7 @@ class User(UserMixin, db.Model):
                 <p>SKA Refereeing</p>
                 """
             )
-            try:
+            try: mail.send(email)
-                mail.send(email)
             except SMTPException as exception:
                 write('system.log', f'SMTP Error when trying to delete account {username} with error: {exception}')
         return True, message
@@ -219,11 +217,14 @@ class User(UserMixin, db.Model):
         if password: self.set_password(password)
         old_email = self.get_email()
         if email:
+            try:
                 for entry in User.query.all():
                     if entry.get_email() == email and not entry == self: return False, f'The email address {email} is already in use.'
+            except SQLAlchemyError as exception:
+                write('system.log', f'Database error when setting default dataset {self.id}: {exception}')
+                return False, f'Database error {exception}.'
             self.set_email(email)
-        try:
+        try: db.session.commit()
-            db.session.commit()
         except SQLAlchemyError as exception:
             db.session.rollback()
             write('system.log', f'Database error when updating user {self.get_username()}: {exception}')
@@ -257,8 +258,7 @@ class User(UserMixin, db.Model):
                 <p>SKA Refereeing</p>
                 """
             )
-            try:
+            try: mail.send(message)
-                mail.send(message)
             except SMTPException as exception:
                 write('system.log', f'SMTP Error when trying to update account {self.get_username()} with error: {exception}')
         return True, f'Account {self.get_username()} has been updated.'

ref-test/app/quiz/views.py

@@ -1,10 +1,12 @@
 from ..forms.quiz import StartQuiz
 from ..models import Entry, Test
 from ..tools.forms import send_errors_to_client
+from ..tools.logs import write
 from ..tools.test import redirect_if_started
 
-from flask import abort, Blueprint, jsonify, redirect, render_template, request, session
+from flask import Blueprint, jsonify, render_template, request, session
-from flask.helpers import flash, url_for
+from flask.helpers import abort, flash, redirect, url_for
+from sqlalchemy.exc import SQLAlchemyError
 
 from datetime import datetime
 
@@ -37,7 +39,10 @@ def _start():
             entry.set_club(request.form.get('club'))
             entry.set_email(request.form.get('email'))
             code = request.form.get('test_code').replace('—', '').lower()
-            test = Test.query.filter_by(code=code).first()
+            try: test = Test.query.filter_by(code=code).first()
+            except SQLAlchemyError as exception:
+                write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+                return abort(500)
             entry.test = test
             entry.user_code = request.form.get('user_code')
             entry.user_code = None if entry.user_code == '' else entry.user_code.lower()
@@ -59,16 +64,23 @@ def _start():
 @quiz.route('/quiz/')
 def _quiz():
     id = session.get('id')
+    try:
         if not id or not Entry.query.filter_by(id=id).first():
             flash('Your session was not recognised. Please sign in to the quiz again.', 'error')
             session.pop('id', None)
             return redirect(url_for('quiz._start'))
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     return render_template('/quiz/client.html')
 
 @quiz.route('/result/')
 def _result():
     id = session.get('id')
-    entry = Entry.query.filter_by(id=id).first()
+    try: entry = Entry.query.filter_by(id=id).first()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+        return abort(500)
     if not entry: return abort(404)
     session.pop('id',None)
     score = round(100*entry.result['score']/entry.result['max'])

ref-test/app/tools/auth.py

@@ -1,18 +1,23 @@
 from .data import load
 from ..models import User
+from ..tools.logs import write
 
-from flask import abort, redirect
+from flask.helpers import abort, flash, redirect, url_for
-from flask.helpers import flash, url_for
 from flask_login import current_user
+from sqlalchemy.exc import SQLAlchemyError
 
 from functools import wraps
 
 def require_account_creation(function):
     @wraps(function)
     def wrapper(*args, **kwargs):
+        try:
             if User.query.count() == 0:
                 flash('Please register a user account.', 'alert')
                 return redirect(url_for('admin._register'))
+        except SQLAlchemyError as exception:
+            write('system.log', f'Database error when checking for existing accounts: {exception}')
+            return abort(500)
         return function(*args, **kwargs)
     return wrapper
 

ref-test/app/tools/data.py

@@ -1,8 +1,9 @@
 from ..models import Dataset
+from ..tools.logs import write
 
 from flask import current_app as app
-from flask import flash, redirect
+from flask.helpers import abort, flash, redirect, url_for
-from flask.helpers import url_for
+from sqlalchemy.exc import SQLAlchemyError
 
 import json
 from pathlib import Path
@@ -76,7 +77,10 @@ def get_tag_list(dataset:list):
 def check_dataset_exists(function):
     @wraps(function)
     def wrapper(*args, **kwargs):
-        datasets = Dataset.query.all()
+        try: datasets = Dataset.query.all()
+        except SQLAlchemyError as exception:
+            write('system.log', f'Database error when checking existing datasets: {exception}')
+            return abort(500)
         if not datasets:
             flash('There are no available question datasets. Please upload a question dataset first, or use the question editor to create a new dataset.', 'error')
             return redirect(url_for('admin._questions'))

ref-test/app/tools/forms.py

@@ -1,7 +1,9 @@
 
 from ..extensions import db
+from ..tools.logs import write
 
 from flask import jsonify
+from sqlalchemy.exc import SQLAlchemyError
 from wtforms.validators import ValidationError
 
 import json
@@ -47,7 +49,10 @@ def get_time_options():
 
 def get_dataset_choices():
     from ..models import Dataset
-    datasets = Dataset.query.all()
+    try: datasets = Dataset.query.all()
+    except SQLAlchemyError as exception:
+        write('system.log', f'Database error when fetching dataset lists: {exception}')
+        return []
     dataset_choices = []
     for dataset in datasets:
         label = dataset.get_name()

ref-test/app/tools/test.py

@@ -1,8 +1,10 @@
 from .data import randomise_list
 from ..models import Entry
+from ..tools.logs import write
 
-from flask import redirect, request, session
+from flask import request, session
-from flask.helpers import url_for
+from flask.helpers import abort, redirect, url_for
+from sqlalchemy.exc import SQLAlchemyError
 
 from functools import wraps
 
@@ -129,8 +131,11 @@ def redirect_if_started(function):
     @wraps(function)
     def wrapper(*args, **kwargs):
         id = session.get('id')
-        if request.method == 'GET' and id and Entry.query.filter_by(id=id).first():
+        try:
-            return redirect(url_for('quiz._quiz'))
+            if request.method == 'GET' and id and Entry.query.filter_by(id=id).first(): return redirect(url_for('quiz._quiz'))
+        except SQLAlchemyError as exception:
+            write('system.log', f'Database error when checking if test has been started: {exception}')
+            return abort(500)
         return function(*args, **kwargs)
     return wrapper
 

ref-test/app/view/views.py

@@ -2,10 +2,12 @@ from ..forms.admin import EditDataset
 from ..models import Dataset, User
 from ..tools.forms import get_dataset_choices, send_errors_to_client
 from ..tools.data import check_dataset_exists
+from ..tools.logs import write
 
-from flask import Blueprint, flash, jsonify, redirect, render_template, request
+from flask import Blueprint, jsonify, render_template, request
-from flask.helpers import url_for
+from flask.helpers import abort, flash, redirect, url_for
 from flask_login import login_required
+from sqlalchemy.exc import SQLAlchemyError
 
 view = Blueprint(
     name='view',
@@ -32,9 +34,13 @@ def _view():
 @login_required
 @check_dataset_exists
 def _view_console(id:str=None):
+    try:
         dataset = Dataset.query.filter_by(id=id).first()
         datasets = Dataset.query.count()
         users = User.query.all()
+    except SQLAlchemyError as exception:
+            write('system.log', f'Database error when processing request \'{request.url}\': {exception}')
+            return abort(500)
     if not dataset:
         flash('Invalid dataset ID.', 'error')
         return redirect(url_for('admin._questions'))

ref-test/reset.py

@@ -8,8 +8,7 @@ import sys
 from getpass import getpass
 
 with app.app_context():
-    try:
+    try: users = User.query.all()
-        users = User.query.all()
     except SQLAlchemyError as exception:
         sys.exit('Database error:', exception)
     print('')