that way you could pass this dict as json to `$().datepicker();`
e.g.:
```
class DateRangeFilter(BaseReportFilter):
   template_name = 'hqwebapp/filters/daterange.html'
   
   @property
   def datepicker_config(self):
       return {
         changeMonth: true,
         changeYear: true,
         showButtonPanel: true,
         dateFormat: 'yy-mm-dd',
         maxDate: null,
         numberOfMonths: 1
     }
     
     @property
     def filter_context(self):
          return {
               'datepicker_config': self.datepicker_config,
          }
```
and in `hqwebapp/filters/daterange.html` the js block would have...
```
<script>
$('.date-range').datepicker({{ datepicker_config|JSON }});
</script>
```
Basically, you shouldn't need to subclass the datespan filter for this. You're just creating a new filter. Does that make sense? Datespan is (terribly) so involved with the specific report use case because those reports rely on having the datespan injected into the request object, which you shouldn't need for this. Make sense?