Simplify CRUD logic

Whe needs CRUD? If a page exists, you edit it. If it doesn't, the same form
creates it. No more sections on a page? It gets automatically deleted. The
only thing the user has to remember is: nothing. Brilliant, right?

cms/models.py

@@ -60,9 +60,9 @@ class Numbered:
 
 class BasePage(Numbered, models.Model):
     '''Abstract base model for pages'''
-    number = models.PositiveIntegerField(_('number'), blank=True)
+    title = VarCharField(_('page'))
-    title = VarCharField(_('title'))
     slug = models.SlugField(_('slug'), blank=True, unique=True)
+    number = models.PositiveIntegerField(_('number'), blank=True)
     menu = models.BooleanField(_('visible in menu'), default=True)
 
     def __str__(self):
@@ -85,10 +85,10 @@ class BaseSection(Numbered, PolymorphicModel):
     '''Abstract base model for sections'''
     TYPES = [] # Will be populated by @register_model()
     page = models.ForeignKey(swapper.get_model_name('cms', 'Page'), verbose_name=_('page'), related_name='sections', on_delete=models.PROTECT)
-    type = VarCharField(_('type'), blank=True)
+    title = VarCharField(_('section'))
+    type = VarCharField(_('type'))
     number = models.PositiveIntegerField(_('number'), blank=True)
 
-    title = VarCharField(_('title'), blank=True)
     content = models.TextField(_('content'), blank=True)
     image = models.ImageField(_('image'), blank=True)
     video = EmbedVideoField(_('video'), blank=True, help_text=_('Paste a YouTube, Vimeo, or SoundCloud link'))

cms/static/cms/cms.scss

@@ -66,10 +66,6 @@ div.spacer {
   clear: both;
 }
 
-header, nav, section, footer {
-  padding: 1rem;
-}
-
 nav {
   padding: 0;
 
@@ -181,9 +177,16 @@ div.edit {
   text-align: center;
   &.page {
     position: fixed;
-    left: 1em;
+    right: 1em;
-    top: 1em;
+    bottom: 1em;
     z-index: 1000;
+    img {
+      width: 75px;
+      height: auto;
+    }
+    a:before, button:before, a:after, button:after {
+      display: none;
+    }
   }
 }
 
@@ -210,7 +213,6 @@ div.edit a, div.edit button, a.edit{
 
 section {
   clear: both;
-  border-bottom: 2px solid $blue;
 
   div.image {
     img {
@@ -259,8 +261,8 @@ section.contactsection {
 /* Form elements */
 
 form.cms {
-  div.wrapper {
+  section {
-    overflow: hidden;
+    margin-top: 3em;
   }
 
   div.global_error {
@@ -288,8 +290,8 @@ form.cms {
     clear: both;
     box-sizing: border-box;
 
-    &.type, &.number {
+    &.type, &.number, &.slug {
-      width: 75%;
+      width: 77%;
       clear: none;
       float: left;
     }
@@ -308,15 +310,16 @@ form.cms {
     div.label {
       font-weight: 700;
     }
-    input, select, .textarea, div.textarea {
+    input {
-      border: 1px solid black;
+      //font-weight: bold;
     }
   }
 
   div.label, label {
-    font-size: 0.8rem;
+    font-size: 0.7rem;
     font-weight: 400;
     text-align: left;
+    margin-bottom: 2px;
   }
 
   div.input {
@@ -336,39 +339,32 @@ form.cms {
   input, select, textarea {
     background: white;
     color: black;
-    border: 1px solid #aaa;
+    border: 0.5px solid #ccc;
+    border-radius: 3px;
     font-size: 1rem;
     display: block;
     width: 100%;
     box-sizing: border-box;
     margin: 0;
-    padding: 5px;
+    padding: 5px 8px;
     font-family: inherit;
   }
   input[type=checkbox] {
+    width: auto;
     display: inline-block;
     vertical-align: middle;
   }
+  input[name$=title] {
+    font-weight: bold;
+  }
   textarea {
     font-size: 1rem;
-    padding: 5px 5px;
     height: 15em;
+    line-height: 1.5;
   }
-
-  input[type=checkbox] {
-    width: auto;
-  }
-
   select {
     background: white;
-  }
+    padding-left: 3px;
-
-  div.filefield {
-    border: 1px solid #aaa;
-    background: white;
-    padding: 4px;
-
-    input { border: none }
   }
 
   ul.errorlist {

cms/static/cms/cms.scss.css

@@ -49,9 +49,6 @@ div.spacer {
   height: 1rem;
   clear: both; }
 
-header, nav, section, footer {
-  padding: 1rem; }
-
 nav {
   padding: 0; }
   nav button#hamburger {
@@ -133,9 +130,14 @@ div.edit {
   text-align: center; }
   div.edit.page {
     position: fixed;
-    left: 1em;
+    right: 1em;
-    top: 1em;
+    bottom: 1em;
     z-index: 1000; }
+    div.edit.page img {
+      width: 75px;
+      height: auto; }
+    div.edit.page a:before, div.edit.page button:before, div.edit.page a:after, div.edit.page button:after {
+      display: none; }
 
 div.edit a, div.edit button, a.edit {
   font-family: inherit;
@@ -155,8 +157,7 @@ div.edit a, div.edit button, a.edit {
     content: ' ]'; }
 
 section {
-  clear: both;
+  clear: both; }
-  border-bottom: 2px solid #3573a8; }
   section div.image img {
     width: 100%; }
   section div.title {
@@ -182,8 +183,8 @@ section.contactsection textarea, section.contactsection input {
   font-family: inherit; }
 
 /* Form elements */
-form.cms div.wrapper {
+form.cms section {
-  overflow: hidden; }
+  margin-top: 3em; }
 
 form.cms div.global_error {
   border: 2px dotted red;
@@ -205,8 +206,8 @@ form.cms div.formfield {
   margin-bottom: 10px;
   clear: both;
   box-sizing: border-box; }
-  form.cms div.formfield.type, form.cms div.formfield.number {
+  form.cms div.formfield.type, form.cms div.formfield.number, form.cms div.formfield.slug {
-    width: 75%;
+    width: 77%;
     clear: none;
     float: left; }
   form.cms div.formfield.number {
@@ -222,13 +223,11 @@ form.cms div.formfield.error {
 form.cms div.formfield.required div.label {
   font-weight: 700; }
 
-form.cms div.formfield.required input, form.cms div.formfield.required select, form.cms div.formfield.required .textarea, form.cms div.formfield.required div.textarea {
-  border: 1px solid black; }
-
 form.cms div.label, form.cms label {
-  font-size: 0.8rem;
+  font-size: 0.7rem;
   font-weight: 400;
-  text-align: left; }
+  text-align: left;
+  margin-bottom: 2px; }
 
 form.cms div.input {
   overflow: hidden; }
@@ -244,36 +243,32 @@ form.cms span.required {
 form.cms input, form.cms select, form.cms textarea {
   background: white;
   color: black;
-  border: 1px solid #aaa;
+  border: 0.5px solid #ccc;
+  border-radius: 3px;
   font-size: 1rem;
   display: block;
   width: 100%;
   box-sizing: border-box;
   margin: 0;
-  padding: 5px;
+  padding: 5px 8px;
   font-family: inherit; }
 
 form.cms input[type=checkbox] {
+  width: auto;
   display: inline-block;
   vertical-align: middle; }
 
+form.cms input[name$=title] {
+  font-weight: bold; }
+
 form.cms textarea {
   font-size: 1rem;
-  padding: 5px 5px;
+  height: 15em;
-  height: 15em; }
+  line-height: 1.5; }
-
-form.cms input[type=checkbox] {
-  width: auto; }
 
 form.cms select {
-  background: white; }
-
-form.cms div.filefield {
-  border: 1px solid #aaa;
   background: white;
-  padding: 4px; }
+  padding-left: 3px; }
-  form.cms div.filefield input {
-    border: none; }
 
 form.cms ul.errorlist {
   margin: 0;

cms/static/cms/edit.svg

@@ -0,0 +1,75 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   version="1"
+   viewBox="0 0 48 48"
+   enable-background="new 0 0 48 48"
+   id="svg6"
+   sodipodi:docname="edit.svg"
+   inkscape:version="0.92.4 (5da689c313, 2019-01-14)">
+  <metadata
+     id="metadata12">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:format>image/svg+xml</dc:format>
+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+        <dc:title />
+      </cc:Work>
+    </rdf:RDF>
+  </metadata>
+  <defs
+     id="defs10" />
+  <sodipodi:namedview
+     pagecolor="#ffffff"
+     bordercolor="#666666"
+     borderopacity="1"
+     objecttolerance="10"
+     gridtolerance="10"
+     guidetolerance="10"
+     inkscape:pageopacity="0"
+     inkscape:pageshadow="2"
+     inkscape:window-width="1920"
+     inkscape:window-height="1075"
+     id="namedview8"
+     showgrid="true"
+     inkscape:zoom="13.906433"
+     inkscape:cx="58.141489"
+     inkscape:cy="18.442256"
+     inkscape:window-x="0"
+     inkscape:window-y="0"
+     inkscape:window-maximized="0"
+     inkscape:current-layer="svg6">
+    <inkscape:grid
+       type="xygrid"
+       id="grid887" />
+  </sodipodi:namedview>
+  <circle
+     fill="#4CAF50"
+     cx="24"
+     cy="24"
+     r="21"
+     id="circle2" />
+  <g
+     id="g895"
+     transform="matrix(0.49467333,-0.05078122,-0.05078122,0.49467333,-9.7836852,14.587579)"
+     style="fill:#ffffff;fill-opacity:1">
+    <path
+       inkscape:connector-curvature="0"
+       id="path889"
+       d="M 50,48 H 60 L 85,23 75,13 50,38 Z"
+       style="fill:#ffffff;fill-opacity:1;stroke:none;stroke-width:0.2;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1" />
+    <path
+       inkscape:connector-curvature="0"
+       id="path891"
+       d="M 78,10 88,20 94,14 84,4 Z"
+       style="fill:#ffffff;fill-opacity:1;stroke:none;stroke-width:0.2;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1" />
+  </g>
+</svg>

cms/static/cms/ok.svg

@@ -0,0 +1,60 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   version="1"
+   viewBox="0 0 48 48"
+   enable-background="new 0 0 48 48"
+   id="svg828"
+   sodipodi:docname="ok.svg"
+   inkscape:version="0.92.4 (5da689c313, 2019-01-14)">
+  <metadata
+     id="metadata834">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:format>image/svg+xml</dc:format>
+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+      </cc:Work>
+    </rdf:RDF>
+  </metadata>
+  <defs
+     id="defs832" />
+  <sodipodi:namedview
+     pagecolor="#ffffff"
+     bordercolor="#666666"
+     borderopacity="1"
+     objecttolerance="10"
+     gridtolerance="10"
+     guidetolerance="10"
+     inkscape:pageopacity="0"
+     inkscape:pageshadow="2"
+     inkscape:window-width="1920"
+     inkscape:window-height="1075"
+     id="namedview830"
+     showgrid="false"
+     inkscape:zoom="4.9166667"
+     inkscape:cx="-11.389831"
+     inkscape:cy="24"
+     inkscape:window-x="0"
+     inkscape:window-y="0"
+     inkscape:window-maximized="0"
+     inkscape:current-layer="svg828" />
+  <circle
+     fill="#4CAF50"
+     cx="24"
+     cy="24"
+     r="21"
+     id="circle824" />
+  <polygon
+     fill="#CCFF90"
+     points="34.6,14.6 21,28.2 15.4,22.6 12.6,25.4 21,33.8 37.4,17.4"
+     id="polygon826"
+     style="fill:#ffffff;fill-opacity:1" />
+</svg>

cms/templates/admin.html

@@ -0,0 +1 @@
+{% extends 'cms/admin.html' %}

cms/templates/cms/admin.html

@@ -0,0 +1,19 @@
+{% load static %}
+{% load i18n %}
+
+<!DOCTYPE html>
+<html lang="{% get_current_language as lang%}{{lang}}">
+  <head>
+    <title>{% block title %}{% endblock %}</title>
+    <meta charset="utf-8"/>
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+    <link rel="stylesheet" href="{% static 'cms/cms.scss.css' %}">
+    {% block extrahead %}{% endblock %}
+  </head>
+  <body>
+    {% block content %}
+    {% endblock %}
+
+    {% block extrabody %}{% endblock %}
+  </body>
+</html>

cms/templates/cms/edit.html

@@ -1,19 +1,16 @@
-{% extends 'base.html' %}
+{% extends 'admin.html' %}
-{% load i18n %}
+{% load static i18n %}
+
+{% block title %}{% trans 'Edit' %} {{form.instance}}{% endblock %}
 
 {% block content %}
   <form method="POST" enctype="multipart/form-data" class="cms">
     {% csrf_token %}
     {{form.media}}
-    <div class="edit page">
-      <button>{% trans 'save' %}</button>
-    </div>
 
+    {% if form %}
       <section>
         <div class="wrapper">
-        <div class="title">
-          <h1>{{form.instance}}</h1>
-        </div>
           {% if form.errors or formset.errors %}
             <div class="global_error">
               {% trans 'Please correct the error(s) below and save again' %}
@@ -26,16 +23,9 @@
               {% include 'cms/formfield.html' with field=field %}
             {% endif %}
           {% endfor %}
-        {% if form.instance.pk %}
-          <div class="formfield">
-            <div class="input">
-              <input type="checkbox" name="delete" id="id_delete"> <label for="id_delete">{% trans 'Delete' %}</label>
-            </div>
-          </div>
-        {% endif %}
-
         </div>
       </section>
+    {% endif %}
 
     {% if formset %}
       {{formset.management_form}}
@@ -46,7 +36,6 @@
         {% endfor %}
         <section>
           <div class="wrapper">
-            <h1>{{form.instance}}</h1>
             <div class="subform">
               {% for field in form.visible_fields %}
                 {% if field.name == 'DELETE' and not form.instance.pk %}
@@ -62,13 +51,20 @@
         </section>
       {% endfor %}
     {% endif %}
+
+    <div class="edit page">
+      <button><img src="{% static 'cms/ok.svg' %}"></button>
+    </div>
   </form>
 {% endblock %}
 
 {% block extrabody %}
   <script type="text/javascript" src="/static/admin/js/urlify.js"></script>
   <script>
-    // https://stackoverflow.com/a/25621277
+    document.addEventListener("DOMContentLoaded", function(event) {
+
+        // Auto-resize <textarea's>
+
         var tx = document.getElementsByTagName('textarea');
         for (var i = 0; i < tx.length; i++) {
             tx[i].setAttribute('style', 'height:0;overflow-y:hidden;');
@@ -80,14 +76,12 @@
             this.style.height = (this.scrollHeight) + 'px';
         }
 
+        // My own implementation of Django's prepopulate.js
+
         var slugfield = document.getElementById('id_slug');
         var titlefield = document.getElementById('id_title');
-
-    /* My own implementation of Django's prepopulate.js */
-
         if (slugfield && titlefield) {
             var virgin = slugfield.value === '';
-
             if (virgin) {
                 titlefield.addEventListener('input', function(event) {
                     if (virgin) {
@@ -100,8 +94,9 @@
             }
         }
 
-    {% if fields_per_type %}
+        // Auto-hide non-relevant fields, based on type field
 
+        {% if fields_per_type %}
         var typefield = document.getElementById('id_type');
         fields_per_type = {{fields_per_type|safe}};
 
@@ -148,5 +143,6 @@
             show_relevant_fields(typefield.value.toLowerCase());
         }
         {% endif %}
+    });
   </script>
 {% endblock %}

cms/templates/cms/new.html

@@ -1,3 +0,0 @@
-{% extends 'cms/edit.html' %}
-
-{% block formset %}{% endblock %}

cms/templates/cms/page.html

@@ -1,5 +1,5 @@
 {% extends 'base.html' %}
-{% load i18n %}
+{% load static %}
 {% load cms %}
 
 {% block title %}{{block.super}} - {{page.title}}{% endblock %}
@@ -11,7 +11,7 @@
 
   {% if user.is_staff %}
     <div class="edit page">
-      <a href="{% if page.slug %}{% url 'cms:updatepage' page.pk %}{% else %}{% url 'cms:updatehomepage' %}{% endif %}">{% trans 'edit this page' %}</a>
+      <a href="{% if page.slug %}{% url 'cms:editpage' page.slug %}{% else %}{% url 'cms:editpage' %}{% endif %}"><img src="{% static 'cms/edit.svg' %}"></a>
     </div>
   {% endif %}
 

cms/urls.py

@@ -1,14 +1,12 @@
 from django.urls import path
-from .views import PageView, UpdatePage, CreatePage, UpdateSection, CreateSection
+from .views import PageView, EditPage, CreatePage
 
 app_name = 'cms'
 
 urlpatterns = [
-    path('updatepage/', UpdatePage.as_view(), {'slug': ''}, name='updatehomepage'),
+    path('edit/', EditPage.as_view(), name='editpage'),
-    path('updatepage/<int:pk>/', UpdatePage.as_view(), name='updatepage'),
+    path('<slug:slug>/edit/', EditPage.as_view(), name='editpage'),
-    path('updatesection/<int:pk>/', UpdateSection.as_view(), name='updatesection'),
     path('createpage/', CreatePage.as_view(), name='createpage'),
-    path('createsection/<int:pk>', CreateSection.as_view(), name='createsection'),
     path('', PageView.as_view(), name='page'),
     path('<slug:slug>/', PageView.as_view(), name='page'),
 ]

cms/views.py

@@ -2,8 +2,10 @@ import json
 import swapper
 
 from django.views import generic
+from django.http import Http404
 from django.shortcuts import redirect
 from django.views.generic.edit import FormMixin
+from django.views.generic.detail import SingleObjectMixin
 from django.contrib.admin.utils import NestedObjects
 from django.core.exceptions import ImproperlyConfigured
 from django.contrib.contenttypes.models import ContentType
@@ -63,24 +65,7 @@ class SectionFormSetView(SectionView):
             kwargs['formset'] = self.get_formset()
         return super().get_context_data(**kwargs)
 
-class MenuMixin:
+class PageView(generic.DetailView):
-    '''Add pages to template context'''
-    def get_context_data(self, **kwargs):
-        context = super().get_context_data(**kwargs)
-        pages = Page.objects.filter(menu=True)
-        context.update({
-            'pages': pages,
-        })
-        return context
-
-class MemoryMixin:
-    '''Remember the previous page in session'''
-    def dispatch(self, request, *args, **kwargs):
-        if request.user.is_authenticated:
-            request.session['previous_url'] = request.path
-        return super().dispatch(request, *args, **kwargs)
-
-class PageView(MenuMixin, MemoryMixin, generic.DetailView):
     '''View of a page with heterogeneous (polymorphic) sections'''
     model = Page
     template_name = 'cms/page.html'
@@ -99,7 +84,13 @@ class PageView(MenuMixin, MemoryMixin, generic.DetailView):
 
     def get(self, request, *args, **kwargs):
         '''Initialize sections and render final response'''
+        try:
             page = self.object = self.get_object()
+        except Http404:
+            if self.request.user.has_perm('cms_page_create'):
+                return redirect('cms:editpage', self.kwargs['slug'])
+            else:
+                raise
         context = self.get_context_data(**kwargs)
         sections = page.sections.all()
         for section in sections:
@@ -135,15 +126,46 @@ class PageView(MenuMixin, MemoryMixin, generic.DetailView):
         })
         return self.render_to_response(context)
 
-# The following views require a logged-in staff member
-
-class StaffRequiredMixin(UserPassesTestMixin):
-    def test_func(self):
-        return self.request.user.is_staff
-
-class TypeMixin(MenuMixin):
     def get_context_data(self, **kwargs):
         context = super().get_context_data(**kwargs)
+        pages = Page.objects.filter(menu=True)
+        context.update({
+            'pages': pages,
+        })
+        return context
+
+class EditPage(UserPassesTestMixin, generic.UpdateView):
+    model = Page
+    form_class = PageForm
+    template_name = 'cms/edit.html'
+
+    def setup(self, *args, slug='', **kwargs):
+        '''Supply a default argument for slug'''
+        super().setup(*args, slug=slug, **kwargs)
+
+    def test_func(self):
+        return self.request.user.has_perm('cms_page_change')
+
+    def get_form_kwargs(self):
+        kwargs = super().get_form_kwargs()
+        kwargs.update({'label_suffix': ''})
+        return kwargs
+
+    def form_valid(self, form):
+        object = form.save()
+        return redirect(object.get_absolute_url())
+
+    def get(self, request, *args, **kwargs):
+        try:
+            page = self.object = self.get_object()
+        except Http404:
+            return CreatePage.as_view()(request, slug=self.kwargs['slug'])
+        return super().get(request, *args, **kwargs)
+
+    def get_context_data(self, **kwargs):
+        context = super().get_context_data(**kwargs)
+        if 'formset' not in context:
+            context['formset'] = SectionFormSet(instance=self.object, form_kwargs={'label_suffix': ''})
         fields_per_type = {}
         for model, _ in Section.TYPES:
             ctype = ContentType.objects.get(
@@ -157,38 +179,6 @@ class TypeMixin(MenuMixin):
         })
         return context
 
-class BaseUpdateView(generic.UpdateView):
-    template_name = 'cms/edit.html'
-
-    def get_form_kwargs(self):
-        kwargs = super().get_form_kwargs()
-        kwargs.update({'label_suffix': ''})
-        return kwargs
-
-    def form_valid(self, form):
-        if 'delete' in self.request.POST:
-            collector = NestedObjects(using='default')
-            collector.collect([self.object])
-            self.template_name = 'cms/confirm.html'
-            return self.render_to_response(self.get_context_data(
-                deleted = collector.nested(),
-                protected = collector.protected,
-                object = self.object,
-            ))
-        else:
-            form.save()
-        return redirect(self.request.session.get('previous_url'))
-
-class UpdatePage(StaffRequiredMixin, TypeMixin, BaseUpdateView):
-    model = Page
-    form_class = PageForm
-
-    def get_context_data(self, **kwargs):
-        context = super().get_context_data(**kwargs)
-        if 'formset' not in context:
-            context['formset'] = SectionFormSet(instance=self.object, form_kwargs={'label_suffix': ''})
-        return context
-
     def post(self, request, *args, **kwargs):
         self.object = self.get_object()
         form = self.get_form()
@@ -202,21 +192,10 @@ class UpdatePage(StaffRequiredMixin, TypeMixin, BaseUpdateView):
     def form_invalid(self, form, formset):
         return self.render_to_response(self.get_context_data(form=form, formset=formset))
 
-class UpdateSection(StaffRequiredMixin, TypeMixin, BaseUpdateView):
+class CreatePage(generic.CreateView):
-    model = Section
-    form_class = SectionForm
-
-class CreatePage(StaffRequiredMixin, MenuMixin, generic.CreateView):
     model = Page
     form_class = PageForm
-    template_name = 'cms/new.html'
+    template_name = 'cms/edit.html'
 
-class CreateSection(StaffRequiredMixin, TypeMixin, generic.CreateView):
+    def get_form_kwargs(self, *args, **kwargs):
-    model = Section
+        return {'initial': {'slug': self.kwargs['slug']}}
-    form_class = SectionForm
-    template_name = 'cms/new.html'
-
-    def form_valid(self, form):
-        form.instance.page = Page.objects.get(pk=self.kwargs.get('pk'))
-        form.save()
-        return redirect(self.request.session.get('previous_url'))

example/app/models.py

@@ -23,7 +23,7 @@ class TextSection(Section):
 
 @register_model('Button')
 class ButtonSection(Section):
-    fields = ['button_text', 'button_link']
+    fields = ['title', 'href']
     class Meta:
         proxy = True