FacetedSearch does not accept sort configuration

[tptlab]

• ElasticSearch: 7.5.2 on Ubuntu
• Python: 3.8.1
• elasticsearch-dsl: 7.1.0

The document says FaucetedSearch accept configuration option sort as a class attribute.

sort
tuple or list of fields on which the results should be sorted.

So I tried to create the following class.

class BlogSearch(FacetedSearch):
    index = 'blogs'

    doc_types = [Blog, Post]
    fields = ['title', 'content']

    sort = ('-published_at',)

    def search(self):
        s = super().search()
        return s.filter('term', published=True)

Then it raises TypeError.

>>> BlogSearch().execute()
Traceback (most recent call last):
File "<console>", line 1, in <module>
File "***/site-packages/elasticsearch_dsl/faceted_search.py", line 271, in __init__
	self._s = self.build_search()
File "***/site-packages/elasticsearch_dsl/faceted_search.py", line 381, in build_search
	s = self.sort(s)
TypeError: 'tuple' object is not callable

I tried sort = '-publisehd_at' but got the same error. What kind of argument should be set?

BlogSearch(sort=('-published_at',)) works fine, but I'd like to set the default sort order.

[miguelgrinberg]

The documentation is incorrect. sort is passed as an argument in the constructor, it is not a class attribute.