fix plus mixin for rest_framework 3.0
diff --git a/planetstack/core/xoslib/methods/plus.py b/planetstack/core/xoslib/methods/plus.py
index 1e4cdf5..9ace688 100644
--- a/planetstack/core/xoslib/methods/plus.py
+++ b/planetstack/core/xoslib/methods/plus.py
@@ -13,6 +13,8 @@
     # This will cause a descendant class to pull in the methods defined
     # above. See rest_framework/serializers.py: _get_declared_fields().
     base_fields = {"backendIcon": backendIcon, "backendHtml": backendHtml}
+    # Rest_framework 3.0 uses _declared_fields instead of base_fields
+    _declared_fields = {"backendIcon": backendIcon, "backendHtml": backendHtml}
 
     def getBackendIcon(self, obj):
         return obj.getBackendIcon()
diff --git a/planetstack/core/xoslib/methods/sliceplus.py b/planetstack/core/xoslib/methods/sliceplus.py
index fffd997..b302aec 100644
--- a/planetstack/core/xoslib/methods/sliceplus.py
+++ b/planetstack/core/xoslib/methods/sliceplus.py
@@ -9,7 +9,7 @@
 from plus import PlusSerializerMixin
 
 class SlicePlusIdSerializer(serializers.ModelSerializer, PlusSerializerMixin):
-        id = serializers.Field()

+        id = serializers.ReadOnlyField()

 

         sliceInfo = serializers.SerializerMethodField("getSliceInfo")

         humanReadableName = serializers.SerializerMethodField("getHumanReadableName")