Introduce handle_errors decorator

server.py

@@ -67,9 +67,20 @@ def render_endpoint(endpoint, flashtext=None, **kargs):
 	request.url_rule = Rule(request.path, endpoint=endpoint)
 	return app.view_functions[endpoint](**kargs)
 
+def handle_errors(endpoint, text, code, *errors, **epargs):
+	def wrapper(func):
+		@wraps(func)
+		def decorator(*args, **kwargs):
+			try:
+				return func(*args, **kwargs)
+			except errors:
+				return render_endpoint(endpoint, text, **epargs), code
+		return decorator
+	return wrapper
+
 @app.errorhandler(404)
 def handle_not_found(e):
-	return render_endpoint('index', 'Diese Seite existiert nicht!')
+	return render_endpoint('index', 'Diese Seite existiert nicht!'), 404
 
 @app.route('/')
 @register_navbar('Home', icon='home')
@@ -99,13 +110,12 @@ def videos():
 
 @app.route('/course/<id>')
 @app.route('/course/<int:numid>')
+@handle_errors('videos', 'Diese Veranstaltung existiert nicht!', 404, IndexError)
 def course(numid=None, id=None):
 	if numid:
 		courses = query('SELECT * FROM courses WHERE id = ? AND (? OR visible)', numid, ismod())
 	else:
 		courses = query('SELECT * FROM courses WHERE handle = ? AND (? OR visible)', id, ismod())
-	if not courses:
-		return render_endpoint('index', 'Diese Veranstaltung existiert nicht!'), 404
 	lectures = query('SELECT * FROM lectures WHERE course_id = ? AND (? OR visible)', courses[0]['id'], ismod())
 	videos = query('''
 			SELECT videos.*, (videos.downloadable AND courses.downloadable) as downloadable, formats.description AS format_description
@@ -124,11 +134,10 @@ def faq():
 	return render_template('faq.html')
 
 @app.route('/play/<int:id>')
+@handle_errors('videos', 'Diese Vorlesung existiert nicht!', 404, IndexError)
 def play(id):
 	lectures = query('SELECT * FROM lectures WHERE id = ? AND (? OR visible)', id, ismod())
 	videos = query('SELECT * FROM videos WHERE lecture_id = ? AND (? OR visible)', id, ismod())
-	if not lectures:
-		return render_endpoint('videos', 'Diese Vorlesung existiert nicht!'), 404
 	if not videos:
 		flash('Zu dieser Vorlesung wurden noch keine Videos veröffentlicht!')
 	courses = query('SELECT * FROM courses WHERE id = ? AND (? OR (visible AND listed))', lectures[0]['course_id'], ismod())