Improve merge support for records with no uuid

for now we "pretend" they have a uuid still, custom view is
responsible for determining the value for each row if needed

tailbone/grids/core.py

@@ -170,6 +170,21 @@ class Grid(object):
                   'myfield': myrender,
               },
           )
+
+    .. attribute row_uuid_getter::
+
+       Optional callable to obtain the "UUID" (sic) value for each
+       data row.  The default assumption as that each row object has a
+       ``uuid`` attribute, but when that isn't the case, *and* the
+       grid needs to support checkboxes, we must "pretend" by
+       injecting some custom value to the ``uuid`` of the row data.
+
+       If necssary, set this to a callable like so::
+
+          def fake_uuid(row):
+              return row.some_custom_key
+
+          grid.row_uuid_getter = fake_uuid
     """
 
     def __init__(self, key, data, columns=None, width='auto', request=None,
@@ -182,7 +197,7 @@ class Grid(object):
                  sortable=False, sorters={}, default_sortkey=None, default_sortdir='asc',
                  pageable=False, default_pagesize=None, default_page=1,
                  checkboxes=False, checked=None, check_handler=None, check_all_handler=None,
-                 checkable=None,
+                 checkable=None, row_uuid_getter=None,
                  clicking_row_checks_box=False, click_handlers=None,
                  main_actions=[], more_actions=[], delete_speedbump=False,
                  ajax_data_url=None, component='tailbone-grid',
@@ -243,6 +258,7 @@ class Grid(object):
         self.check_handler = check_handler
         self.check_all_handler = check_all_handler
         self.checkable = checkable
+        self.row_uuid_getter = row_uuid_getter
         self.clicking_row_checks_box = clicking_row_checks_box
 
         self.click_handlers = click_handlers or {}
@@ -1425,6 +1441,16 @@ class Grid(object):
             })
         return columns
 
+    def get_uuid_for_row(self, rowobj):
+
+        # use custom getter if set
+        if self.row_uuid_getter:
+            return self.row_uuid_getter(rowobj)
+
+        # otherwise fallback to normal uuid, if present
+        if hasattr(rowobj, 'uuid'):
+            return rowobj.uuid
+
     def get_buefy_data(self):
         """
         Returns a list of data rows for the grid, for use with Buefy table.
@@ -1481,8 +1507,9 @@ class Grid(object):
 
             # maybe add UUID for convenience
             if 'uuid' not in self.columns:
-                if hasattr(rowobj, 'uuid'):
+                uuid = self.get_uuid_for_row(rowobj)
-                    row['uuid'] = rowobj.uuid
+                if uuid:
+                    row['uuid'] = uuid
 
             # set action URL(s) for row, as needed
             self.set_action_urls(row, rowobj, i)

tailbone/templates/grids/buefy.mako

@@ -192,7 +192,7 @@
        % if grid.check_all_handler:
        @check-all="${grid.check_all_handler}"
        % endif
-       % if isinstance(grid.checkable, six.string_types):
+       % if isinstance(grid.checkable, str):
        :is-row-checkable="${grid.row_checkable}"
        % elif grid.checkable:
        :is-row-checkable="row => row._checkable"

tailbone/templates/master/merge.mako

@@ -123,7 +123,7 @@
         <div class="level-item">
           ${h.form(request.current_route_url(), **{'@submit': 'submitSwapForm'})}
           ${h.csrf_token(request)}
-          ${h.hidden('uuids', value='{},{}'.format(object_to_keep.uuid, object_to_remove.uuid))}
+          ${h.hidden('uuids', value=f'{keeping_uuid},{removing_uuid}')}
           <b-button native-type="submit"
                     :disabled="swapFormSubmitting">
             {{ swapFormButtonText }}
@@ -134,7 +134,7 @@
         <div class="level-item">
           ${h.form(request.current_route_url(), **{'@submit': 'submitMergeForm'})}
           ${h.csrf_token(request)}
-          ${h.hidden('uuids', value='{},{}'.format(object_to_remove.uuid, object_to_keep.uuid))}
+          ${h.hidden('uuids', value=f'{removing_uuid},{keeping_uuid}')}
           ${h.hidden('commit-merge', value='yes')}
           <b-button type="is-primary"
                     native-type="submit"

tailbone/views/master.py

@@ -441,6 +441,7 @@ class MasterView(View):
             'checkable': self.checkbox,
             'clicking_row_checks_box': self.clicking_row_checks_box,
             'assume_local_times': self.has_local_times,
+            'row_uuid_getter': self.get_uuid_for_grid_row,
         }
 
         if self.sortable or self.pageable or self.filterable:
@@ -453,6 +454,16 @@ class MasterView(View):
         defaults.update(kwargs)
         return defaults
 
+    def get_uuid_for_grid_row(self, obj):
+        """
+        If possible, this should return a "UUID" value to uniquely
+        identify the given object.  Default of course is to use the
+        actual ``uuid`` attribute of the object, if present.  This
+        value is needed by grids when checkboxes are used.
+        """
+        if hasattr(obj, 'uuid'):
+            return obj.uuid
+
     def configure_grid(self, grid):
         """
         Perform "final" configuration for the main data grid.
@@ -2046,17 +2057,31 @@ class MasterView(View):
 
         return []
 
+    def get_merge_objects(self):
+        """
+        Must return 2 objects, obtained somehow from the request,
+        which are to be (potentially) merged.
+
+        :returns: 2-tuple of ``(object_to_remove, object_to_keep)``,
+           or ``None``.
+        """
+        uuids = self.request.POST.get('uuids', '').split(',')
+        if len(uuids) == 2:
+            cls = self.get_model_class()
+            object_to_remove = self.Session.get(cls, uuids[0])
+            object_to_keep = self.Session.get(cls, uuids[1])
+            if object_to_remove and object_to_keep:
+                return object_to_remove, object_to_keep
+
     def merge(self):
         """
         Preview and execute a merge of two records.
         """
         object_to_remove = object_to_keep = None
         if self.request.method == 'POST':
-            uuids = self.request.POST.get('uuids', '').split(',')
+            objects = self.get_merge_objects()
-            if len(uuids) == 2:
+            if objects:
-                object_to_remove = self.Session.get(self.get_model_class(), uuids[0])
+                object_to_remove, object_to_keep = objects
-                object_to_keep = self.Session.get(self.get_model_class(), uuids[1])
-
                 if object_to_remove and object_to_keep and self.request.POST.get('commit-merge') == 'yes':
                     msg = str(object_to_remove)
                     try:
@@ -2073,13 +2098,17 @@ class MasterView(View):
 
         remove = self.get_merge_data(object_to_remove)
         keep = self.get_merge_data(object_to_keep)
-        return self.render_to_response('merge', {'object_to_remove': object_to_remove,
+        return self.render_to_response('merge', {
-                                                 'object_to_keep': object_to_keep,
+            'object_to_remove': object_to_remove,
-                                                 'view_url': lambda obj: self.get_action_url('view', obj),
+            'object_to_keep': object_to_keep,
-                                                 'merge_fields': self.get_merge_fields(),
+            'removing_uuid': self.get_uuid_for_grid_row(object_to_remove),
-                                                 'remove_data': remove,
+            'keeping_uuid': self.get_uuid_for_grid_row(object_to_keep),
-                                                 'keep_data': keep,
+            'view_url': lambda obj: self.get_action_url('view', obj),
-                                                 'resulting_data': self.get_merge_resulting_data(remove, keep)})
+            'merge_fields': self.get_merge_fields(),
+            'remove_data': remove,
+            'keep_data': keep,
+            'resulting_data': self.get_merge_resulting_data(remove, keep),
+        })
 
     def validate_merge(self, removing, keeping):
         """