FIX: Prevent creating duplicate cable types

assets/forms.py

@@ -1,6 +1,7 @@
 from django import forms
 
 from assets import models
+from django.db.models import Q
 
 
 class AssetForm(forms.ModelForm):
@@ -40,3 +41,12 @@ class CableTypeForm(forms.ModelForm):
     class Meta:
         model = models.CableType
         fields = '__all__'
+
+    def clean(self):
+        form_data = self.cleaned_data
+        queryset = models.CableType.objects.filter(Q(plug=form_data['plug']) & Q(socket=form_data['socket']) & Q(circuits=form_data['circuits']) & Q(cores=form_data['cores']))
+        # Being identical to itself doesn't count...
+        print(self.instance.id)
+        if queryset.exists() and self.instance.pk != queryset[0].pk:
+            raise forms.ValidationError("A cable type that exactly matches this one already exists, please use that instead.", code="notunique")
+        return form_data

assets/models.py

@@ -3,7 +3,6 @@ from django.core.exceptions import ValidationError
 from django.db import models, connection
 from django.urls import reverse
 
-from django.db.models import F
 from django.db.models.signals import pre_save
 from django.dispatch.dispatcher import receiver
 

assets/templates/cable_type_form.html

@@ -8,7 +8,11 @@
       {% if create %}Create{% elif edit %}Edit{% endif %} Cable Type
   </h1>
 </div>
-<form method="post" id="asset_update_form" action="{% url 'asset_create'%}">
+{% if create %}
+<form method="POST" action="{% url 'cable_type_create'%}">
+{% elif edit %}
+<form method="POST" action="{% url 'cable_type_update' object.id %}">
+{% endif %}
 {% include 'form_errors.html' %}
 {% csrf_token %}
 <input type="hidden" name="id" value="{{ object.id|default:0 }}" hidden=true>

assets/views.py

@@ -277,6 +277,9 @@ class CableTypeCreate(generic.CreateView):
 
         return context
 
+    def get_success_url(self):
+        return reverse("cable_type_detail", kwargs={"pk": self.object.pk })
+
 class CableTypeUpdate(generic.UpdateView):
     model = models.CableType
     template_name = "cable_type_form.html"
@@ -287,3 +290,6 @@ class CableTypeUpdate(generic.UpdateView):
         context["edit"] = True
 
         return context
+
+    def get_success_url(self):
+        return reverse("cable_type_detail", kwargs={"pk": self.object.pk })