Fix bug in groups widgets

Refresh with no services selected would generate an
exception in the group selection/creation widget.
This just fixes the initialization.

Signed-off-by: Mic Bowman <mic.bowman@intel.com>

exchange-contract/pdo/contracts/jupyter/groups.py

@@ -192,8 +192,8 @@ def __init__(self, state : pbuilder.state.State, bindings : pbuilder.bindings.Bi
         super().__init__([self.group_name, self.services, self.submit_button, self.feedback])
 
     def reset_widget(self) :
-        self.services.reset_widget()
         self.group_name.value = ''
+        self.services.reset_widget()
 
     def submit_button_click(self, b) :
         """Create the provisioning services group
@@ -230,16 +230,20 @@ def update_preferred_list(self, change) :
         if change['type'] == 'change' and change['name'] == 'value' :
             value = self.preferred_service.value
             selection = self.services.selection
+            if not selection :
+                selection = ['unknown']
             if value not in selection :
                 value = selection[0]
 
             self.preferred_service.options = selection
             self.preferred_service.value = value
 
     def reset_widget(self) :
-        self.services.reset_widget()
         self.group_name.value = ''
-        self.preferred_service.value = ''
+
+        self.services.reset_widget()
+        self.preferred_service.options = ['unknown']
+        self.preferred_service.value = 'unknown'
 
     def submit_button_click(self, b) :
         """Create the enclave services group
@@ -295,19 +299,23 @@ def update_persistent_list(self, change) :
         if change['type'] == 'change' and change['name'] == 'value' :
             value = self.persistent_service.value
             selection = self.services.selection
+            if not selection :
+                selection = ['unknown']
             if value not in selection :
                 value = selection[0]
 
             self.persistent_service.options = selection
             self.persistent_service.value = value
 
     def reset_widget(self) :
-        self.services.reset_widget()
         self.group_name.value = ''
-        self.persistent_service.value = ''
         self.replicas.value = 2
         self.duration.value = 120
 
+        self.services.reset_widget()
+        self.persistent_service.options = ['unknown']
+        self.persistent_service.value =  'unknown'
+
     def submit_button_click(self, b) :
         """Create the storage services group
         """

exchange-contract/pdo/contracts/jupyter/services.py

@@ -205,6 +205,7 @@ def selection(self) :
         return self.service_list.value
 
     def reset_widget(self) :
+        self.service_list.options = self.create_service_list()
         self.service_list.value = []
 
     def create_service_list(self) :