Default to _labels=on on JSON/CSV links with foreign keys, refs #266

datasette/views/base.py

@@ -169,20 +169,20 @@ class BaseView(RenderMixin):
             raise
         # Convert rows and columns to CSV
         headings = data["columns"]
-        # if there are columns_expanded we need to add additional headings
-        columns_expanded = set(data.get("columns_expanded") or [])
-        if columns_expanded:
+        # if there are expanded_columns we need to add additional headings
+        expanded_columns = set(data.get("expanded_columns") or [])
+        if expanded_columns:
             headings = []
             for column in data["columns"]:
                 headings.append(column)
-                if column in columns_expanded:
+                if column in expanded_columns:
                     headings.append("{}_label".format(column))
 
         async def stream_fn(r):
             writer = csv.writer(r)
             writer.writerow(headings)
             for row in data["rows"]:
-                if not columns_expanded:
+                if not expanded_columns:
                     # Simple path
                     writer.writerow(row)
                 else:
@@ -349,17 +349,24 @@ class BaseView(RenderMixin):
                     extras = await extras
             else:
                 extras = extra_template_data
+            url_labels_extra = {}
+            if data.get("expandable_columns"):
+                url_labels_extra = {"_labels": "on"}
             context = {
                 **data,
                 **extras,
                 **{
-                    "url_json": path_with_format(request, "json"),
+                    "url_json": path_with_format(request, "json", {
+                        **url_labels_extra,
+                    }),
                     "url_csv": path_with_format(request, "csv", {
-                        "_size": "max"
+                        "_size": "max",
+                        **url_labels_extra
                     }),
                     "url_csv_dl": path_with_format(request, "csv", {
                         "_dl": "1",
-                        "_size": "max"
+                        "_size": "max",
+                        **url_labels_extra
                     }),
                     "extra_css_urls": self.ds.extra_css_urls(),
                     "extra_js_urls": self.ds.extra_js_urls(),

datasette/views/table.py

@@ -573,7 +573,7 @@ class TableView(RowTableShared):
             filter_columns = filter_columns[1:]
 
         # Expand labeled columns if requested
-        columns_expanded = []
+        expanded_columns = []
         expandable_columns = self.expandable_columns(name, table)
         columns_to_expand = None
         try:
@@ -595,7 +595,7 @@ class TableView(RowTableShared):
                 column = fk["column"]
                 if column not in columns_to_expand:
                     continue
-                columns_expanded.append(column)
+                expanded_columns.append(column)
                 # Gather the values
                 column_index = columns.index(column)
                 values = [row[column_index] for row in rows]
@@ -771,7 +771,8 @@ class TableView(RowTableShared):
             "truncated": results.truncated,
             "table_rows_count": table_rows_count,
             "filtered_table_rows_count": filtered_table_rows_count,
-            "columns_expanded": columns_expanded,
+            "expanded_columns": expanded_columns,
+            "expandable_columns": expandable_columns,
             "columns": columns,
             "primary_keys": pks,
             "units": units,

tests/test_html.py

@@ -289,6 +289,21 @@ def test_table_csv_json_export_links(app_client):
     assert expected == actual
 
 
+def test_csv_json_export_links_include_labels_if_foreign_keys(app_client):
+    response = app_client.get('/fixtures/facetable')
+    assert response.status == 200
+    links = Soup(response.body, "html.parser").find("p", {
+        "class": "export-links"
+    }).findAll("a")
+    actual = [l["href"].split("/")[-1] for l in links]
+    expected = [
+        "facetable.json?_labels=on",
+        "facetable.csv?_labels=on&_size=max",
+        "facetable.csv?_dl=1&_labels=on&_size=max"
+    ]
+    assert expected == actual
+
+
 def test_row_html_simple_primary_key(app_client):
     response = app_client.get('/fixtures/simple_primary_key/1')
     assert response.status == 200