?_size=max option, closes #249

datasette/app.py

@@ -869,6 +869,8 @@ class TableView(RowTableShared):
         # Handle ?_page_size=500
         page_size = request.raw_args.get('_size')
         if page_size:
+            if page_size == 'max':
+                page_size = self.max_returned_rows
             try:
                 page_size = int(page_size)
                 if page_size < 0:

docs/json_api.rst

@@ -131,9 +131,9 @@ Special table arguments
 
 The Datasette table view takes a number of special querystring arguments:
 
-``?_size=1000``
+``?_size=1000`` or ``?_size=max``
     Sets a custom page size. This cannot exceed the ``max_returned_rows`` option
-    passed to ``datasette serve``.
+    passed to ``datasette serve``. Use ``max`` to get ``max_returned_rows``.
 
 ``?_sort=COLUMN``
     Sorts the results by the specified column.

tests/test_api.py

@@ -451,6 +451,7 @@ def test_table_with_reserved_word_name(app_client):
     ('/test_tables/paginated_view.json', 201, 5),
     ('/test_tables/no_primary_key.json?_size=25', 201, 9),
     ('/test_tables/paginated_view.json?_size=25', 201, 9),
+    ('/test_tables/paginated_view.json?_size=max', 201, 3),
     ('/test_tables/123_starts_with_digits.json', 0, 1),
 ])
 def test_paginate_tables_and_views(app_client_longer_time_limit, path, expected_rows, expected_pages):
@@ -458,6 +459,7 @@ def test_paginate_tables_and_views(app_client_longer_time_limit, path, expected_
     count = 0
     while path:
         response = app_client_longer_time_limit.get(path, gather_request=False)
+        assert 200 == response.status
         count += 1
         fetched.extend(response.json['rows'])
         path = response.json['next_url']