Validate attribute type for type relation

Ensure the attribute type is validation when specifying a target servertype instread of crashing with an exception or HTTP 500.

Author: kofrezo

serveradmin/serverdb/admin.py

@@ -8,7 +8,7 @@
 
 from serveradmin.serverdb.forms import (
     ServertypeAttributeAdminForm,
-    ServertypeAdminForm,
+    ServertypeAdminForm, AttributeAdminForm,
 )
 from serveradmin.serverdb.models import (
     Servertype,
@@ -68,6 +68,7 @@ class ServerAdmin(admin.ModelAdmin):
 
 
 class AttributeAdmin(admin.ModelAdmin):
+    form = AttributeAdminForm
     list_display = [
         'attribute_id',
         'type',

serveradmin/serverdb/forms.py

@@ -1,7 +1,7 @@
 from django import forms
 from django.core.exceptions import ValidationError
 
-from serveradmin.serverdb.models import ServertypeAttribute
+from serveradmin.serverdb.models import ServertypeAttribute, Attribute
 
 
 class ServertypeAdminForm(forms.ModelForm):
@@ -33,3 +33,14 @@ def clean(self):
                 'ip_addr_type is null is not possible!')
 
         super().clean()
+
+
+class AttributeAdminForm(forms.ModelForm):
+    class Meta:
+        model = Attribute
+        fields = '__all__'
+
+    def clean(self):
+        if self.cleaned_data['type'] != 'relation' and self.cleaned_data['target_servertype'] is not None:
+            raise ValidationError('Attribute type must be relation when target servertype is selected!')
+        super().clean()