implement save/restore on viewer configuration

python/perspective/perspective/tests/viewer/test_viewer.py

@@ -244,3 +244,25 @@ def test_viewer_delete_without_table(self):
         assert viewer.table_name is not None
         assert viewer.table is not None
         assert viewer.filters == []
+
+    def test_save_restore(self):
+        table = Table({"a": [1, 2, 3]})
+        viewer = PerspectiveViewer(plugin="x_bar", filters=[["a", "==", 2]])
+        viewer.load(table)
+
+        # Save config
+        config = viewer.save()
+        assert viewer.filters == [["a", "==", 2]]
+        assert config["filters"] == [["a", "==", 2]]
+        assert viewer.plugin == "x_bar"
+        assert config["plugin"] == "x_bar"
+
+        # reset configuration
+        viewer.reset()
+        assert viewer.plugin == "hypergrid"
+        assert viewer.filters == []
+
+        # restore configuration
+        viewer.restore(**config)
+        assert viewer.filters == [["a", "==", 2]]
+        assert viewer.plugin == "x_bar"

python/perspective/perspective/viewer/viewer.py

@@ -6,6 +6,7 @@
 # the Apache License 2.0.  The full license can be found in the LICENSE file.
 #
 
+import six
 from random import random
 from .validate import validate_plugin, validate_columns, validate_row_pivots, validate_column_pivots, \
     validate_aggregates, validate_sort, validate_filters, validate_plugin_config
@@ -184,6 +185,26 @@ def replace(self, data):
         if self.table is not None:
             self.table.replace(data)
 
+    def save(self):
+        '''Get the viewer's attribute as a dictionary, symmetric with `restore` so that a
+           viewer's configuration can be reproduced.'''
+        return {
+            'row_pivots': self.row_pivots,
+            'column_pivots': self.column_pivots,
+            'filters': self.filters,
+            'sort': self.sort,
+            'aggregates': self.aggregates,
+            'columns': self.columns,
+            'plugin': self.plugin,
+        }
+
+    def restore(self, **kwargs):
+        '''Restore a given set of attributes, passed as kwargs (e.g. dictionary). Symmetric with `save` so that
+        a given viewer's configuration can be reproduced'''
+        for k, v in six.iteritems(kwargs):
+            if k in ('row_pivots', 'column_pivots', 'filters', 'sort', 'aggregates', 'columns', 'plugin'):
+                setattr(self, k, v)
+
     def reset(self):
         '''Resets the viewer's attributes and state, but does not delete or
         modify the underlying `Table`.