404 & 500 pages (hedyorg#992)

* Nice 404 & 500 pages.
* Return proper status codes in 404 and 500 pages

app.py

@@ -447,7 +447,7 @@ def programs_page(request):
 @app.route('/quiz/start/<level>', methods=['GET'])
 def get_quiz_start(level):
     if not config.get('quiz-enabled') and g.lang != 'nl':
-        return 'Hedy quiz disabled!', 404
+        return utils.page_404 (TRANSLATIONS, render_main_menu('adventures'), current_user(request) ['username'], requested_lang (), 'Hedy quiz disabled!')
     else:
         g.lang = lang = requested_lang()
         g.prefix = '/hedy'
@@ -469,7 +469,7 @@ def quiz_data_file_for(level):
 @app.route('/quiz/quiz_questions/<level_source>/<question_nr>/<attempt>', methods=['GET'])
 def get_quiz(level_source, question_nr, attempt):
     if not config.get('quiz-enabled') and g.lang != 'nl':
-        return 'Hedy quiz disabled!', 404
+        return utils.page_404 (TRANSLATIONS, render_main_menu('adventures'), current_user(request) ['username'], requested_lang (), 'Hedy quiz disabled!')
     else:
         # Reading the yaml file
         quiz_data = quiz_data_file_for(level_source)
@@ -516,7 +516,7 @@ def get_quiz(level_source, question_nr, attempt):
 @app.route('/quiz/submit_answer/<level_source>/<question_nr>/<attempt>', methods=["POST"])
 def submit_answer(level_source, question_nr, attempt):
     if not config.get('quiz-enabled') and g.lang != 'nl':
-        return 'Hedy quiz disabled!', 404
+        return utils.page_404 (TRANSLATIONS, render_main_menu('adventures'), current_user(request) ['username'], requested_lang (), 'Hedy quiz disabled!')
     else:
         # Get the chosen option from the request form with radio buttons
         option = request.form["radio_option"]
@@ -610,7 +610,7 @@ def adventure_page(adventure_name, level):
 
     # If requested adventure does not exist, return 404
     if not adventure_name in adventures:
-        return 'No such Hedy adventure!', 404
+        return utils.page_404 (TRANSLATIONS, render_main_menu('adventures'), current_user(request) ['username'], requested_lang (), TRANSLATIONS.get_translations (requested_lang (), 'ui').get ('no_such_adventure'))
 
     adventure = adventures[adventure_name]
 
@@ -636,7 +636,7 @@ def adventure_page(adventure_name, level):
 
     # If requested level is not in adventure, return 404
     if not level in adventure['levels']:
-        abort(404)
+        return utils.page_404 (TRANSLATIONS, render_main_menu('adventures'), current_user(request) ['username'], requested_lang (), TRANSLATIONS.get_translations (requested_lang (), 'ui').get ('no_such_adventure_level'))
 
     adventures_for_level = load_adventures_per_level(requested_lang(), level)
     level_defaults_for_lang = LEVEL_DEFAULTS[requested_lang()]
@@ -671,9 +671,9 @@ def index(level, step):
         try:
             g.level = level = int(level)
         except:
-            return 'No such Hedy level!', 404
+            return utils.page_404 (TRANSLATIONS, render_main_menu('hedy'), current_user(request) ['username'], requested_lang (), TRANSLATIONS.get_translations (requested_lang (), 'ui').get ('no_such_level'))
     else:
-        return 'No such Hedy level!', 404
+        return utils.page_404 (TRANSLATIONS, render_main_menu('hedy'), current_user(request) ['username'], requested_lang (), TRANSLATIONS.get_translations (requested_lang (), 'ui').get ('no_such_level'))
 
     g.lang = requested_lang()
     g.prefix = '/hedy'
@@ -685,12 +685,12 @@ def index(level, step):
     if step and isinstance(step, str) and len(step) > 2:
         result = DATABASE.program_by_id(step)
         if not result:
-            return 'No such program', 404
+            return utils.page_404 (TRANSLATIONS, render_main_menu('hedy'), current_user(request) ['username'], requested_lang (), TRANSLATIONS.get_translations (requested_lang (), 'ui').get ('no_such_program'))
         # If the program is not public, allow only the owner of the program, the admin user and the teacher users to access the program
         user = current_user(request)
         public_program = 'public' in result and result['public']
         if not public_program and user['username'] != result['username'] and not is_admin(request) and not is_teacher(request):
-            return 'No such program!', 404
+            return utils.page_404 (TRANSLATIONS, render_main_menu('hedy'), current_user(request) ['username'], requested_lang (), TRANSLATIONS.get_translations (requested_lang (), 'ui').get ('no_such_program'))
         loaded_program = {'code': result['code'], 'name': result['name'], 'adventure_name': result.get('adventure_name')}
         if 'adventure_name' in result:
             adventure_name = result['adventure_name']
@@ -720,7 +720,7 @@ def view_program(id):
 
     result = DATABASE.program_by_id(id)
     if not result:
-        return 'No such program', 404
+        return utils.page_404 (TRANSLATIONS, render_main_menu('hedy'), current_user(request) ['username'], requested_lang (), TRANSLATIONS.get_translations (requested_lang (), 'ui').get ('no_such_program'))
 
     # Default to the language of the program's author(but still respect)
     # the switch if given.
@@ -771,7 +771,7 @@ def client_messages():
 def internal_error(exception):
     import traceback
     print(traceback.format_exc())
-    return "<h1>500 Internal Server Error</h1>", 500
+    return utils.page_500 (TRANSLATIONS, render_main_menu('hedy'), current_user(request) ['username'], requested_lang ())
 
 @app.route('/index.html')
 @app.route('/')

coursedata/texts/en.yaml

@@ -26,6 +26,15 @@ ui:
     commands_title: "Commands"
     by: "by"
     start_quiz: "Start quiz"
+    default_404: "We could not find that page..."
+    default_500: "Something went wrong..."
+    go_back_to_main: "Go back to the main page"
+    no_such_level: "No such Hedy level!"
+    no_such_class: "No such Hedy class!"
+    invalid_class_link: "Invalid link for joining the class"
+    no_such_adventure: "No such Hedy adventure!"
+    no_such_adventure_level: "No such level for this Hedy adventure!"
+    no_such_program: "No such Hedy program!"
 ClientErrorMessages:
     Transpile_warning: "Warning!"
     Transpile_error: "We can't run your program."

hedyweb.py

@@ -34,7 +34,7 @@ def get_translations(self, language, section):
 def render_code_editor_with_tabs(request, level_defaults, lang, max_level, level_number, menu, translations, version, loaded_program, adventures, adventure_name):
 
   if not level_defaults:
-    abort(404)
+    return utils.page_404 (translations, menu, current_user(request) ['username'], lang, translations.get_translations (lang, 'ui').get ('no_such_level'))
 
 
   arguments_dict = {}

templates/404.html

@@ -0,0 +1,7 @@
+{% extends "layout.html" %}
+
+{% block body %}
+  <div class="w-full text-center"><img class="inline-block" src="/images/404.jpeg" style="width: 40%;"></div>
+  <div class="w-full text-center"><p class="text-lg font-bold">{{page_error or ui.default_404}}</p></div>
+  <div class="w-full text-center mt-8"><button class="green-btn" style="width: 40%;" onclick="window.location.href = '{{localize_link ('/')}}'">{{ui.go_back_to_main}}</button></div>
+{% endblock %}

templates/500.html

@@ -0,0 +1,7 @@
+{% extends "layout.html" %}
+
+{% block body %}
+  <div class="w-full text-center"><img class="inline-block" src="/images/500.jpeg" style="width: 40%;"></div>
+  <div class="w-full text-center"><p class="text-lg font-bold">{{page_error or ui.default_500}}</p></div>
+  <div class="w-full text-center mt-8"><button class="green-btn" style="width: 40%;" onclick="window.location.href = '{{localize_link ('/')}}'">{{ui.go_back_to_main}}</button></div>
+{% endblock %}

utils.py

@@ -13,6 +13,7 @@
 commonmark_parser = commonmark.Parser ()
 commonmark_renderer = commonmark.HtmlRenderer ()
 from bs4 import BeautifulSoup
+from flask_helpers import render_template
 
 IS_WINDOWS = os.name == 'nt'
 
@@ -177,3 +178,13 @@ def markdown_to_html_tags (markdown):
     _html = commonmark_renderer.render(commonmark_parser.parse (markdown))
     soup = BeautifulSoup(_html, 'html.parser')
     return soup.find_all ()
+
+def page_404 (translations, menu, lang, username, *page_error):
+    if page_error:
+        page_error = page_error [0]
+    return render_template("404.html", menu=menu, username=username, auth=translations.get_translations(lang, 'Auth'), ui=translations.get_translations(lang, 'ui'), page_error=page_error or ''), 404
+
+def page_500 (translations, menu, lang, username, *page_error):
+    if page_error:
+        page_error = page_error [0]
+    return render_template("500.html", menu=menu, username=username, auth=translations.get_translations(lang, 'Auth'), ui=translations.get_translations(lang, 'ui'), page_error=page_error or ''), 500

website/teacher.py

@@ -29,7 +29,7 @@ def get_class (user, class_id):
             return 'Only teachers can retrieve classes', 403
         Class = DATABASE.get_class (class_id)
         if not Class or Class ['teacher'] != user ['username']:
-            return 'No such class', 404
+            return utils.page_404 (TRANSLATIONS, render_main_menu('my-profile'), current_user(request) ['username'], requested_lang (), TRANSLATIONS.get_translations (requested_lang (), 'ui').get ('no_such_class'))
         students = []
         for student_username in Class.get ('students', []):
             student = DATABASE.user_by_username (student_username)
@@ -108,7 +108,7 @@ def delete_class (user, class_id):
     def prejoin_class (class_id, link):
         Class = DATABASE.get_class (class_id)
         if not Class or Class ['link'] != link:
-            return 'No such class', 404
+            return utils.page_404 (TRANSLATIONS, render_main_menu('my-profile'), current_user(request) ['username'], requested_lang (), TRANSLATIONS.get_translations (requested_lang (), 'ui').get ('invalid_class_link'))
         user = {}
         if request.cookies.get (cookie_name):
             token = DATABASE.get_token(request.cookies.get (cookie_name))
@@ -124,7 +124,7 @@ def prejoin_class (class_id, link):
     def join_class (user, class_id, link):
         Class = DATABASE.get_class (class_id)
         if not Class or Class ['link'] != link:
-            return 'No such class', 404
+            return utils.page_404 (TRANSLATIONS, render_main_menu('my-profile'), current_user(request) ['username'], requested_lang (), TRANSLATIONS.get_translations (requested_lang (), 'ui').get ('invalid_class_link'))
 
         DATABASE.add_student_to_class (Class ['id'], user ['username'])
 
@@ -146,5 +146,5 @@ def leave_class (user, class_id, student_id):
     def resolve_class_link (link_id):
         Class = DATABASE.resolve_class_link (link_id)
         if not Class:
-            return 'Invalid link', 404
+            return utils.page_404 (TRANSLATIONS, render_main_menu('my-profile'), current_user(request) ['username'], requested_lang (), TRANSLATIONS.get_translations (requested_lang (), 'ui').get ('invalid_class_link'))
         return redirect(request.url.replace('/hedy/l/' + link_id, '/class/' + Class ['id'] + '/prejoin/' + link_id), code=302)