From 236aa065b2ecfbe5a77870689bae432b89a48b23 Mon Sep 17 00:00:00 2001
From: Simon Willison <swillison@gmail.com>
Date: Sat, 21 Mar 2020 19:28:35 -0700
Subject: [PATCH] "sort" and "sort_desc" metadata properties, closes #702

---
 datasette/views/table.py |  4 ++--
 docs/metadata.rst        | 33 +++++++++++++++++++++++++++
 tests/fixtures.py        |  2 ++
 tests/test_html.py       | 48 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 85 insertions(+), 2 deletions(-)

diff --git a/datasette/views/table.py b/datasette/views/table.py
index b28d6060..96e8922b 100644
--- a/datasette/views/table.py
+++ b/datasette/views/table.py
@@ -402,8 +402,8 @@ class TableView(RowTableShared):
         )
 
         # Allow for custom sort order
-        sort = special_args.get("_sort")
-        sort_desc = special_args.get("_sort_desc")
+        sort = special_args.get("_sort") or table_metadata.get("sort")
+        sort_desc = special_args.get("_sort_desc") or table_metadata.get("sort_desc")
 
         if sort and sort_desc:
             raise DatasetteError("Cannot use _sort and _sort_desc at the same time")
diff --git a/docs/metadata.rst b/docs/metadata.rst
index 5d9155ea..54008550 100644
--- a/docs/metadata.rst
+++ b/docs/metadata.rst
@@ -109,6 +109,39 @@ registered with Pint::
 .. _unit registry: https://github.com/hgrecco/pint/blob/master/pint/default_en.txt
 .. _custom units: http://pint.readthedocs.io/en/latest/defining.html
 
+.. _metadata_default_sort:
+
+Setting a default sort order
+----------------------------
+
+By default Datasette tables are sorted by primary key. You can over-ride this default for a specific table using the ``"sort"`` or ``"sort_desc"`` metadata properties::
+
+    {
+        "databases": {
+            "mydatabase": {
+                "tables": {
+                    "example_table": {
+                        "sort": "created"
+                    }
+                }
+            }
+        }
+    }
+
+Or use ``"sort_desc"`` to sort in descending order::
+
+    {
+        "databases": {
+            "mydatabase": {
+                "tables": {
+                    "example_table": {
+                        "sort_desc": "created"
+                    }
+                }
+            }
+        }
+    }
+
 .. _metadata_sortable_columns:
 
 Setting which columns can be used for sorting
diff --git a/tests/fixtures.py b/tests/fixtures.py
index 0c1b10a0..5cc64a16 100644
--- a/tests/fixtures.py
+++ b/tests/fixtures.py
@@ -304,6 +304,8 @@ METADATA = {
                     "fts_table": "searchable_fts",
                     "fts_pk": "pk",
                 },
+                "attraction_characteristic": {"sort_desc": "pk"},
+                "facet_cities": {"sort": "name"},
             },
             "queries": {
                 "𝐜𝐢𝐭𝐢𝐞𝐬": "select id, name from facet_cities order by id limit 1;",
diff --git a/tests/test_html.py b/tests/test_html.py
index 86880cfd..a0216672 100644
--- a/tests/test_html.py
+++ b/tests/test_html.py
@@ -1095,3 +1095,51 @@ def test_config_template_debug_off(app_client):
     response = app_client.get("/fixtures/facetable?_context=1")
     assert response.status == 200
     assert not response.text.startswith("<pre>{")
+
+
+def test_metadata_sort(app_client):
+    response = app_client.get("/fixtures/facet_cities")
+    assert response.status == 200
+    table = Soup(response.body, "html.parser").find("table")
+    assert table["class"] == ["rows-and-columns"]
+    ths = table.findAll("th")
+    assert ["id", "name\xa0▼"] == [th.find("a").string.strip() for th in ths]
+    rows = [[str(td) for td in tr.select("td")] for tr in table.select("tbody tr")]
+    assert [
+        [
+            '<td class="col-id"><a href="/fixtures/facet_cities/3">3</a></td>',
+            '<td class="col-name">Detroit</td>',
+        ],
+        [
+            '<td class="col-id"><a href="/fixtures/facet_cities/2">2</a></td>',
+            '<td class="col-name">Los Angeles</td>',
+        ],
+        [
+            '<td class="col-id"><a href="/fixtures/facet_cities/4">4</a></td>',
+            '<td class="col-name">Memnonia</td>',
+        ],
+        [
+            '<td class="col-id"><a href="/fixtures/facet_cities/1">1</a></td>',
+            '<td class="col-name">San Francisco</td>',
+        ],
+    ] == rows
+
+
+def test_metadata_sort_desc(app_client):
+    response = app_client.get("/fixtures/attraction_characteristic")
+    assert response.status == 200
+    table = Soup(response.body, "html.parser").find("table")
+    assert table["class"] == ["rows-and-columns"]
+    ths = table.findAll("th")
+    assert ["pk\xa0▲", "name"] == [th.find("a").string.strip() for th in ths]
+    rows = [[str(td) for td in tr.select("td")] for tr in table.select("tbody tr")]
+    assert [
+        [
+            '<td class="col-pk"><a href="/fixtures/attraction_characteristic/2">2</a></td>',
+            '<td class="col-name">Paranormal</td>',
+        ],
+        [
+            '<td class="col-pk"><a href="/fixtures/attraction_characteristic/1">1</a></td>',
+            '<td class="col-name">Museum</td>',
+        ],
+    ] == rows