Copies column instances to be unique per table instance.

Fixes bug 964345.

Incidentally fixes bug 964351 as well by wrapping the dropdown
actions template code in a spaceless tag.

Change-Id: I672cb517d230db235c90a403e9b8ac0740e8732d

horizon/tables/base.py

@@ -617,13 +617,14 @@ def __new__(mcs, name, bases, attrs):
 
         # Gather columns; this prevents the column from being an attribute
         # on the DataTable class and avoids naming conflicts.
-        columns = [(column_name, attrs.pop(column_name)) for
-                   column_name, obj in attrs.items()
-                   if issubclass(type(obj), (opts.column_class, Column))]
-        # add a name attribute to each column
-        for column_name, column in columns:
-            column.name = column_name
+        columns = []
+        for name, obj in attrs.items():
+            if issubclass(type(obj), (opts.column_class, Column)):
+                column_instance = attrs.pop(name)
+                column_instance.name = name
+                columns.append((name, column_instance))
         columns.sort(key=lambda x: x[1].creation_counter)
+
         # Iterate in reverse to preserve final order
         for base in bases[::-1]:
             if hasattr(base, 'base_columns'):
@@ -651,7 +652,8 @@ def __new__(mcs, name, bases, attrs):
             actions_column.classes.append('actions_column')
             actions_column.auto = "actions"
             columns.append(("actions", actions_column))
-        attrs['columns'] = SortedDict(columns)
+        # Store this set of columns internally so we can copy them per-instance
+        attrs['_columns'] = SortedDict(columns)
 
         # Gather and register actions for later access since we only want
         # to instantiate them once.
@@ -698,11 +700,16 @@ class DataTable(object):
     def __init__(self, request, data=None, **kwargs):
         self._meta.request = request
         self._meta.data = data
-        self._populate_data_cache()
         self.kwargs = kwargs
 
-        for column in self.columns.values():
+        # Create a new set
+        columns = []
+        for key, _column in self._columns.items():
+            column = copy.copy(_column)
             column.table = self
+            columns.append((key, column))
+        self.columns = SortedDict(columns)
+        self._populate_data_cache()
 
         # Associate these actions with this table
         for action in self.base_actions.values():

horizon/tables/views.py

@@ -39,7 +39,7 @@ def _get_data_dict(self):
 
     def get_tables(self):
         if not self.table_classes:
-            raise AttributeError('You must specify a one or more DataTable '
+            raise AttributeError('You must specify one or more DataTable '
                                  'classes for the "table_classes" attribute '
                                  'on %s.' % self.__class__.__name__)
         if not self._tables:

horizon/templates/horizon/common/_data_table_row_actions.html

@@ -1,5 +1,6 @@
 {% load horizon %}
 
+{% spaceless %} {# This makes sure whitespace doesn't affect positioning for dropdown. #}
 {% if row_actions|length > 1 %}
 <div class="btn-group">
     {% for action in row_actions %}
@@ -25,3 +26,4 @@
     {% include "horizon/common/_data_table_row_action.html" %}
   {% endfor %}
 {% endif %}
+{% endspaceless %}

horizon/tests/table_tests.py

@@ -308,9 +308,9 @@ def test_table_column(self):
         self.table = MyTable(self.request, TEST_DATA)
         row = self.table.get_rows()[0]
         row3 = self.table.get_rows()[2]
-        id_col = self.table.base_columns['id']
-        name_col = self.table.base_columns['name']
-        value_col = self.table.base_columns['value']
+        id_col = self.table.columns['id']
+        name_col = self.table.columns['name']
+        value_col = self.table.columns['value']
         # transform
         self.assertEqual(row.cells['id'].data, '1')  # Standard attr access
         self.assertEqual(row.cells['name'].data, 'custom object_1')  # Callable
@@ -552,3 +552,18 @@ def test_table_actions(self):
         row_actions = self.table.get_row_actions(TEST_DATA[0])
         self.assertEqual(unicode(row_actions[0].verbose_name), "Delete Me")
         self.assertEqual(unicode(row_actions[1].verbose_name), "Log In")
+
+    def test_column_uniqueness(self):
+        table1 = MyTable(self.request)
+        table2 = MyTable(self.request)
+        # Regression test for launchpad bug 964345.
+        self.assertNotEqual(id(table1), id(table2))
+        self.assertNotEqual(id(table1.columns), id(table2.columns))
+        t1cols = table1.columns.values()
+        t2cols = table2.columns.values()
+        self.assertEqual(t1cols[0].name, t2cols[0].name)
+        self.assertNotEqual(id(t1cols[0]), id(t2cols[0]))
+        self.assertNotEqual(id(t1cols[0].table),
+                            id(t2cols[0].table))
+        self.assertNotEqual(id(t1cols[0].table._data_cache),
+                            id(t2cols[0].table._data_cache))