Closes #575: Allow all valid URL schemes in custom fields

netbox/utilities/forms.py

@@ -4,6 +4,7 @@ import re
 
 from django import forms
 from django.core.urlresolvers import reverse_lazy
+from django.core.validators import URLValidator
 from django.utils.encoding import force_text
 from django.utils.html import format_html
 from django.utils.safestring import mark_safe
@@ -253,6 +254,21 @@ class FilterChoiceField(forms.ModelMultipleChoiceField):
     choices = property(_get_choices, forms.ChoiceField._set_choices)
 
 
+class LaxURLField(forms.URLField):
+    """
+    Custom URLField which allows any valid URL scheme
+    """
+
+    class AnyURLScheme(object):
+        # A fake URL list which "contains" all scheme names abiding by the syntax defined in RFC 3986 section 3.1
+        def __contains__(self, item):
+            if not item or not re.match('^[a-z][0-9a-z+\-.]*$', item.lower()):
+                return False
+            return True
+
+    default_validators = [URLValidator(schemes=AnyURLScheme())]
+
+
 #
 # Forms
 #