Link to BLOB downloads, closes #1046

datasette/app.py

@@ -1303,3 +1303,11 @@ class Urls:
 
     def query(self, database, query):
         return "{}/{}".format(self.database(database), urllib.parse.quote_plus(query))
+
+    def row(self, database, table, row_path):
+        return "{}/{}".format(self.table(database, table), row_path)
+
+    def row_blob(self, database, table, row_path, column):
+        return self.table(database, table) + "/-/blob/{}/{}.blob".format(
+            row_path, urllib.parse.quote_plus(column)
+        )

datasette/static/app.css

@@ -457,6 +457,17 @@ svg.dropdown-menu-icon {
     top: 1px;
 }
 
+.blob-download {
+    display: block;
+    white-space: nowrap;
+    padding-right: 20px;
+    position: relative;
+    background-image: url("data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHZpZXdCb3g9IjAgMCAxNiAxNiIgd2lkdGg9IjE2IiBoZWlnaHQ9IjE2Ij48cGF0aCBmaWxsLXJ1bGU9ImV2ZW5vZGQiIGQ9Ik03LjQ3IDEwLjc4YS43NS43NSAwIDAwMS4wNiAwbDMuNzUtMy43NWEuNzUuNzUgMCAwMC0xLjA2LTEuMDZMOC43NSA4LjQ0VjEuNzVhLjc1Ljc1IDAgMDAtMS41IDB2Ni42OUw0Ljc4IDUuOTdhLjc1Ljc1IDAgMDAtMS4wNiAxLjA2bDMuNzUgMy43NXpNMy43NSAxM2EuNzUuNzUgMCAwMDAgMS41aDguNWEuNzUuNzUgMCAwMDAtMS41aC04LjV6Ij48L3BhdGg+PC9zdmc+");
+    background-size: 16px 16px;
+    background-position: right;
+    background-repeat: no-repeat;
+}
+
 .anim-scale-in {
     animation-name: scale-in;
     animation-duration: 0.15s;

datasette/views/table.py

@@ -167,8 +167,15 @@ class RowTableShared(DataView):
                     display_value = plugin_display_value
                 elif isinstance(value, bytes):
                     display_value = jinja2.Markup(
-                        "<Binary data: {} byte{}>".format(
-                            len(value), "" if len(value) == 1 else "s"
+                        '<a class="blob-download" href="{}">&lt;Binary:&nbsp;{}&nbsp;byte{}&gt;</a>'.format(
+                            self.ds.urls.row_blob(
+                                database,
+                                table,
+                                path_from_row_pks(row, pks, not pks),
+                                column,
+                            ),
+                            len(value),
+                            "" if len(value) == 1 else "s",
                         )
                     )
                 elif isinstance(value, dict):

tests/test_html.py

@@ -1231,12 +1231,12 @@ def test_binary_data_display(app_client):
         [
             '<td class="col-Link type-pk"><a href="/fixtures/binary_data/1">1</a></td>',
             '<td class="col-rowid type-int">1</td>',
-            '<td class="col-data type-bytes">&lt;Binary\xa0data:\xa07\xa0bytes&gt;</td>',
+            '<td class="col-data type-bytes"><a class="blob-download" href="/fixtures/binary_data/-/blob/1/data.blob">&lt;Binary:\xa07\xa0bytes&gt;</a></td>',
         ],
         [
             '<td class="col-Link type-pk"><a href="/fixtures/binary_data/2">2</a></td>',
             '<td class="col-rowid type-int">2</td>',
-            '<td class="col-data type-bytes">&lt;Binary\xa0data:\xa07\xa0bytes&gt;</td>',
+            '<td class="col-data type-bytes"><a class="blob-download" href="/fixtures/binary_data/-/blob/2/data.blob">&lt;Binary:\xa07\xa0bytes&gt;</a></td>',
         ],
     ]
     assert expected_tds == [