Form logic: only save if valid, delete pages when the last sections is deleted

cms/static/cms/cms.scss

@@ -180,6 +180,10 @@ div.edit {
     right: 1em;
     bottom: 1em;
     z-index: 1000;
+    button {
+      padding: 0;
+      outline: none;
+    }
     img {
       width: 75px;
       height: auto;
@@ -262,15 +266,6 @@ form.cms {
     margin-top: 3em;
   }
 
-  div.global_error {
-    border: 2px dotted red;
-    padding: 10px;
-    margin: 1em -10px;
-    background: #f001;
-    color: red;
-    font-weight: bold;
-  }
-
   fieldset {
     padding: 2em;
     margin-bottom: 2em;
@@ -370,7 +365,7 @@ form.cms {
     padding: 0;
     list-style: none;
     color: red;
-    font-size: 12px !important;
+    font-size: 12px;
 
     li {
       margin: 0;
@@ -378,6 +373,20 @@ form.cms {
     }
   }
 
+  div.global_error {
+    border: 2px dotted red;
+    padding: 10px;
+    margin: 1em -10px;
+    background: #f001;
+    color: red;
+    font-weight: bold;
+
+    ul.errorlist {
+      margin: 0;
+      font-size: inherit;
+    }
+  }
+
   .errors {
     color: red;
     font-weight: bold;

cms/static/cms/cms.scss.css

@@ -133,6 +133,9 @@ div.edit {
     right: 1em;
     bottom: 1em;
     z-index: 1000; }
+    div.edit.page button {
+      padding: 0;
+      outline: none; }
     div.edit.page img {
       width: 75px;
       height: auto; }
@@ -183,14 +186,6 @@ section.contact div#message {
 form.cms section {
   margin-top: 3em; }
 
-form.cms div.global_error {
-  border: 2px dotted red;
-  padding: 10px;
-  margin: 1em -10px;
-  background: #f001;
-  color: red;
-  font-weight: bold; }
-
 form.cms fieldset {
   padding: 2em;
   margin-bottom: 2em;
@@ -273,11 +268,22 @@ form.cms ul.errorlist {
   padding: 0;
   list-style: none;
   color: red;
-  font-size: 12px !important; }
+  font-size: 12px; }
   form.cms ul.errorlist li {
     margin: 0;
     padding: 0; }
 
+form.cms div.global_error {
+  border: 2px dotted red;
+  padding: 10px;
+  margin: 1em -10px;
+  background: #f001;
+  color: red;
+  font-weight: bold; }
+  form.cms div.global_error ul.errorlist {
+    margin: 0;
+    font-size: inherit; }
+
 form.cms .errors {
   color: red;
   font-weight: bold; }

cms/templates/cms/edit.html

@@ -11,7 +11,11 @@
     {% if form %}
       <section>
         <div class="wrapper">
-          {% if form.errors or formset.errors %}
+          {% if form.non_field_errors %}
+            <div class="global_error">
+              {{form.non_field_errors}}
+            </div>
+          {% elif form.errors or formset.errors %}
             <div class="global_error">
               {% trans 'Please correct the error(s) below and save again' %}
             </div>

cms/views.py

@@ -1,13 +1,13 @@
 import json
 import swapper
 
+from django.shortcuts import redirect
 from django.views.generic import base, detail, edit
 from django.http import Http404, HttpResponseRedirect
-from django.shortcuts import redirect
+from django.utils.translation import gettext_lazy as _
 from django.core.exceptions import ImproperlyConfigured
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.auth.mixins import UserPassesTestMixin
-#from django.http import HttpResponseRedirect, HttpResponseBadRequest
 
 from .decorators import register_view
 from .forms import PageForm, SectionForm, SectionFormSet
@@ -37,7 +37,7 @@ class SectionFormView(edit.FormMixin, SectionView):
         form = self.get_form()
         if form.is_valid():
             form.save(request)
-            return redirect(self.get_success_url())
+            return HttpResponseRedirect(self.get_success_url())
         return form
 
 class SectionFormSetView(SectionView):
@@ -50,7 +50,7 @@ class SectionFormSetView(SectionView):
         formset = self.get_formset()
         if formset.is_valid():
             formset.save(request)
-            return redirect(self.get_success_url())
+            return HttpResponseRedirect(self.get_success_url())
         return formset
 
     def get_formset(self):
@@ -178,22 +178,26 @@ class EditPage(UserPassesTestMixin, edit.ModelFormMixin, base.TemplateResponseMi
         self.object = self.get_object()
         return self.render_to_response(self.get_context_data())
 
+    def get_formset(self):
+        return SectionFormSet(self.request.POST, self.request.FILES, instance=self.object)
+
     def post(self, request, *args, **kwargs):
         self.object = self.get_object()
         form = self.get_form()
-        if form.is_valid():
-            page = form.save()
-            formset = SectionFormSet(request.POST, request.FILES, instance=page)
-            if formset.is_valid():
-                if formset.save():
-                    if page.slug and not page.sections.exists(): # anymore
-                        page.delete()
-                        return HttpResponseRedirect('/')
-                    return HttpResponseRedirect(page.get_absolute_url())
-                else:
-                    # TODO: show sensible error
-                    formset.errors.append([{}, {'title': ['You have to add sections']}])
-        formset = SectionFormSet(request.POST, request.FILES)
+        formset = self.get_formset()
+
+        if form.is_valid() and formset.is_valid():
+            if not self.object and not formset.has_changed():
+                form.add_error(None, _('You can’t save a new page without adding any sections!'))
+            else:
+                page = form.save()
+                formset.instance = page
+                formset.save()
+                if page.slug and not page.sections.exists():
+                    page.delete()
+                    return HttpResponseRedirect('/')
+                return HttpResponseRedirect(page.get_absolute_url())
+
         return self.render_to_response(self.get_context_data(form=form, formset=formset))
 
 class CreatePage(EditPage):