Provide default renderers for SA mapped tables, where possible

tailbone/grids3/core.py

@@ -152,6 +152,9 @@ class Grid(object):
         else:
             self.enums.pop(key, None)
 
+    def render_generic(self, obj, column_name):
+        return self.obtain_value(obj, column_name)
+
     def render_boolean(self, obj, column_name):
         value = self.obtain_value(obj, column_name)
         return pretty_boolean(value)
@@ -255,11 +258,33 @@ class Grid(object):
         :attr:`model_class`.
         """
         renderers = dict(self.renderers)
-        # for column in self.columns:
-        #     if column not in renderers:
-        #         pass
+
+        if self.model_class:
+            mapper = orm.class_mapper(self.model_class)
+            for prop in mapper.iterate_properties:
+                if isinstance(prop, orm.ColumnProperty) and not prop.key.endswith('uuid'):
+                    if prop.key in self.columns and prop.key not in renderers:
+                        if len(prop.columns) == 1:
+                            coltype = prop.columns[0].type
+                            renderers[prop.key] = self.get_renderer_for_column_type(coltype)
+
         return renderers
 
+    def get_renderer_for_column_type(self, coltype):
+        """
+        Returns an appropriate renderer according to the given SA column type.
+        """
+        if isinstance(coltype, sa.Boolean):
+            return self.render_boolean
+
+        if isinstance(coltype, sa.DateTime):
+            return self.render_datetime
+
+        if isinstance(coltype, GPCType):
+            return self.render_gpc
+
+        return self.render_generic
+
     def checkbox_column_format(self, column_number, row_number, item):
         return HTML.td(self.render_checkbox(item), class_='checkbox')