add missing files

aircox_web/fields.py

@@ -0,0 +1,32 @@
+from django.db import models
+
+
+class BaseMinMaxField:
+    def __init__(self, verbose_name=None, name=None, min=None, max=None,
+                 **kwargs):
+        super().__init__(verbose_name, name, **kwargs)
+        self.min_value = min
+        self.max_value = max
+
+    def minmax(self, value):
+        return min(self.max_value, max(self.min_value, value))
+
+    def to_python(self, value):
+        return self.minmax(super().to_python(value))
+
+    def get_prep_value(self, value):
+        return super().get_prep_value(self.minmax(value))
+
+
+class MinMaxField(BaseMinMaxField, models.IntegerField):
+    pass
+
+class SmallMinMaxField(BaseMinMaxField, models.SmallIntegerField):
+    pass
+
+class PositiveMinMaxField(BaseMinMaxField, models.PositiveIntegerField):
+    pass
+
+class PositiveSmallMinMaxField(BaseMinMaxField, models.PositiveSmallIntegerField):
+    pass
+