improved deletion of recipes

cookbook/models.py

@@ -458,6 +458,9 @@ class Step(ExportModelOperationsMixin('step'), models.Model, PermissionModelMixi
         from cookbook.helper.template_helper import render_instructions
         return render_instructions(self)
 
+    def __str__(self):
+        return f'{self.pk} {self.name}'
+
     class Meta:
         ordering = ['order', 'pk']
         indexes = (GinIndex(fields=["search_vector"]),)

cookbook/templates/generic/delete_template.html

@@ -22,13 +22,11 @@
         </div>
         {{ form|crispy }}
 
-        {% if related_objects %}
+        {% if protected_objects %}
-            {% blocktrans %} <i>{{ object }}</i> could not be deleted because it is still referenced by the following instances: {% endblocktrans %}
+            <h5>{% trans 'Protected' %} <small class="text-muted">The object you are trying to delete is <b>protected</b> by the following references to it.</small></h5>
-            <br/>
+            {% for o in protected_objects %}
-            <br/>
-            {% for o in related_objects %}
                 {% class_name o.model as name %}
-                <h5>{{ name }}</h5>
+                <u>{{ name }}</u>
                 <ul>
                     {% for e in o %}
                         <li>
@@ -36,14 +34,40 @@
                         </li>
                     {% endfor %}
                 </ul>
-
             {% endfor %}
-
-
-            <br/>
         {% endif %}
 
-        <button class="btn btn-success" type="submit" href="{{ success_url }}"><i
+        {% if cascading_objects %}
+            <h5>{% trans 'Cascade' %} <small class="text-muted">The object you are trying to delete is used by the following objects which will <b>also be deleted</b>.</small></h5>
+            {% for o in cascading_objects %}
+                {% class_name o.model as name %}
+                <u>{{ name }}</u>
+                <ul>
+                    {% for e in o %}
+                        <li>
+                            <span class="badge badge-info">#{{ e.id }}</span> {{ e }}
+                        </li>
+                    {% endfor %}
+                </ul>
+            {% endfor %}
+        {% endif %}
+
+        {% if set_null_objects %}
+            <h5>{% trans 'Remove' %} <small class="text-muted">The object you are trying to delete is used by the following objects from which the reference will be removed.</small></h5>
+            {% for o in set_null_objects %}
+                {% class_name o.model as name %}
+                <u>{{ name }}</u>
+                <ul>
+                    {% for e in o %}
+                        <li>
+                            <span class="badge badge-info">#{{ e.id }}</span> {{ e }}
+                        </li>
+                    {% endfor %}
+                </ul>
+            {% endfor %}
+        {% endif %}
+
+        <button class="btn btn-success" type="submit" href="{{ success_url }}" {% if protected_objects %}disabled{% endif %}><i
                 class="fas fa-trash-alt"></i> {% trans 'Confirm' %}</button>
         <a href="javascript:history.back()" class="btn btn-danger"><i class="fas fa-undo-alt"></i> {% trans 'Cancel' %}
         </a>

cookbook/views/delete.py

@@ -1,4 +1,5 @@
 from django.contrib import messages
+from django.db import models
 from django.db.models import ProtectedError
 from django.http import HttpResponseRedirect
 from django.shortcuts import get_object_or_404, render
@@ -24,30 +25,36 @@ class RecipeDelete(GroupRequiredMixin, DeleteView):
     success_url = reverse_lazy('index')
 
     def delete(self, request, *args, **kwargs):
-        obj = self.get_object()
+        self.object = self.get_object()
-
+        # TODO make this more generic so that all delete functions benefit from this
-        related_objects = []
+        if self.get_context_data()['protected_objects']:
-        for x in obj._meta.get_fields():
+            return render(request, template_name=self.template_name, context=self.get_context_data())
-            try:
-                related = x.related_model.objects.filter(**{x.field.name: obj})
-                if related.exists():
-                    related_objects.append(related)
-            except AttributeError:
-                pass
-
-        if related_objects:
-            self.object = obj
-            return render(request, template_name=self.template_name, context=self.get_context_data(related_objects=related_objects))
 
         success_url = self.get_success_url()
-        obj.delete()
+        self.object.delete()
         return HttpResponseRedirect(success_url)
 
     def get_context_data(self, **kwargs):
         context = super(RecipeDelete, self).get_context_data(**kwargs)
         context['title'] = _("Recipe")
-        if 'related_objects' in kwargs:
+
-            context['related_objects'] = kwargs.pop('related_objects')
+        # TODO make this more generic so that all delete functions benefit from this
+        self.object = self.get_object()
+        context['protected_objects'] = []
+        context['cascading_objects'] = []
+        context['set_null_objects'] = []
+        for x in self.object._meta.get_fields():
+            try:
+                related = x.related_model.objects.filter(**{x.field.name: self.object})
+                if related.exists() and x.on_delete == models.PROTECT:
+                    context['protected_objects'].append(related)
+                if related.exists() and x.on_delete == models.CASCADE:
+                    context['cascading_objects'].append(related)
+                if related.exists() and x.on_delete == models.SET_NULL:
+                    context['set_null_objects'].append(related)
+            except AttributeError:
+                pass
+
         return context