snapshot: Use AppView for app page

Tests:

- Enable/disable button is not shown.

- Diagnostics menu item is shown and works.

- Both Configure and manage snapshots tabs are shown.

- Changing configuration works, updated configuration is shown.

- Deleting some snapshots works.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/modules/snapshot/__init__.py

@@ -44,6 +44,8 @@ class SnapshotApp(app_module.App):
 
     _version = 4
 
+    can_be_disabled = False
+
     def __init__(self):
         """Create components for the app."""
         super().__init__()

plinth/modules/snapshot/templates/snapshot.html

@@ -7,7 +7,8 @@
 {% load i18n %}
 
 {% block configuration %}
-  <form id="snapshot-configure" class="form-horizontal" method="post">
+  <form id="snapshot-configure" class="form-horizontal form-configuration"
+        method="post">
     {% csrf_token %}
     <h3>{% trans "Configuration" %}</h3>
     {{ form|bootstrap_horizontal:'col-md-4' }}

plinth/modules/snapshot/tests/test_functional.py

@@ -4,6 +4,7 @@ Functional, browser based tests for snapshot app.
 """
 
 import pytest
+
 from plinth.tests import functional
 
 pytestmark = [pytest.mark.system, pytest.mark.snapshot]
@@ -73,7 +74,8 @@ def _delete_all(browser):
 
 def _create_snapshot(browser):
     functional.visit(browser, '/plinth/sys/snapshot/manage/')
-    functional.submit(browser)  # Click on 'Create Snapshot'
+    create_button = browser.find_by_name('create').first
+    functional.submit(browser, create_button)
 
 
 def _get_count(browser):
@@ -102,7 +104,7 @@ def _set_configuration(browser, free_space, timeline_enabled, software_enabled,
     browser.find_by_name('weekly_limit').fill(weekly)
     browser.find_by_name('monthly_limit').fill(monthly)
     browser.find_by_name('yearly_limit').fill(yearly)
-    functional.submit(browser)
+    functional.submit(browser, form_class='form-configuration')
 
 
 def _get_configuration(browser):

plinth/modules/snapshot/urls.py

@@ -8,7 +8,7 @@ from django.urls import re_path
 from . import views
 
 urlpatterns = [
-    re_path(r'^sys/snapshot/$', views.index, name='index'),
+    re_path(r'^sys/snapshot/$', views.SnapshotAppView.as_view(), name='index'),
     re_path(r'^sys/snapshot/manage/$', views.manage, name='manage'),
     re_path(r'^sys/snapshot/selected/delete$', views.delete_selected,
             name='delete-selected'),

plinth/modules/snapshot/views.py

@@ -19,6 +19,7 @@ from plinth import app as app_module
 from plinth.errors import ActionError
 from plinth.modules import snapshot as snapshot_module
 from plinth.modules import storage
+from plinth.views import AppView
 
 from . import get_configuration
 from .forms import SnapshotForm
@@ -55,29 +56,31 @@ def not_supported_view(request):
                             template_data)
 
 
-def index(request):
-    """Show snapshot list."""
-    if not snapshot_module.is_supported():
-        return not_supported_view(request)
+class SnapshotAppView(AppView):
+    """Show snapshot app main page."""
 
-    status = get_configuration()
-    if request.method == 'POST':
-        form = SnapshotForm(request.POST)
-        if 'update' in request.POST and form.is_valid():
-            update_configuration(request, status, form.cleaned_data)
-            status = get_configuration()
-            form = SnapshotForm(initial=status)
-    else:
-        form = SnapshotForm(initial=status)
+    app_id = 'snapshot'
+    template_name = 'snapshot.html'
+    form_class = SnapshotForm
 
-    app = app_module.App.get('snapshot')
-    return TemplateResponse(
-        request, 'snapshot.html', {
-            'app_info': app.info,
-            'title': app.info.name,
-            'subsubmenu': subsubmenu,
-            'form': form
-        })
+    def get_initial(self):
+        """Return the values to fill in the form."""
+        initial = super().get_initial()
+        initial.update(get_configuration())
+        return initial
+
+    def get_context_data(self, *args, **kwargs):
+        """Add additional context data for template."""
+        context = super().get_context_data(*args, **kwargs)
+        context['subsubmenu'] = subsubmenu
+        return context
+
+    def form_valid(self, form):
+        """Apply the changes submitted in the form."""
+        if 'update' in self.request.POST:
+            update_configuration(self.request, form.initial, form.cleaned_data)
+
+        return super().form_valid(form)
 
 
 def manage(request):