Initial render_cell and foreign_key_tables extras for row

Closes #2619, refs #2050

datasette/views/row.py

@@ -12,7 +12,7 @@ from datasette.utils import (
 from datasette.plugins import pm
 import json
 import sqlite_utils
-from .table import display_columns_and_rows
+from .table import display_columns_and_rows, _get_extras
 
 
 class RowView(DataView):
@@ -104,11 +104,48 @@ class RowView(DataView):
             "primary_key_values": pk_values,
         }
 
+        # Handle _extra parameter (new style)
+        extras = _get_extras(request)
+
+        # Also support legacy _extras parameter for backward compatibility
         if "foreign_key_tables" in (request.args.get("_extras") or "").split(","):
+            extras.add("foreign_key_tables")
+
+        # Process extras
+        if "foreign_key_tables" in extras:
             data["foreign_key_tables"] = await self.foreign_key_tables(
                 database, table, pk_values
             )
 
+        if "render_cell" in extras:
+            # Call render_cell plugin hook for each cell
+            rendered_rows = []
+            for row in rows:
+                rendered_row = {}
+                for value, column in zip(row, columns):
+                    # Call render_cell plugin hook
+                    plugin_display_value = None
+                    for candidate in pm.hook.render_cell(
+                        row=row,
+                        value=value,
+                        column=column,
+                        table=table,
+                        database=database,
+                        datasette=self.ds,
+                        request=request,
+                    ):
+                        candidate = await await_me_maybe(candidate)
+                        if candidate is not None:
+                            plugin_display_value = candidate
+                            break
+                    if plugin_display_value:
+                        rendered_row[column] = str(plugin_display_value)
+                    else:
+                        # Default: convert value to string
+                        rendered_row[column] = "" if value is None else str(value)
+                rendered_rows.append(rendered_row)
+            data["render_cell"] = rendered_rows
+
         return (
             data,
             template_data,

datasette/views/table.py

@@ -1492,7 +1492,7 @@ async def table_view_data(
     async def extra_display_rows(run_display_columns_and_rows):
         return run_display_columns_and_rows["rows"]
 
-    async def extra_render_cells():
+    async def extra_render_cell():
         "Rendered HTML for each cell using the render_cell plugin hook"
         columns = [col[0] for col in results.description]
         rendered_rows = []
@@ -1708,7 +1708,7 @@ async def table_view_data(
         run_display_columns_and_rows,
         extra_display_columns,
         extra_display_rows,
-        extra_render_cells,
+        extra_render_cell,
         extra_debug,
         extra_request,
         extra_query,

tests/test_api.py

@@ -752,6 +752,62 @@ async def test_row_foreign_key_tables(ds_client):
     ]
 
 
+@pytest.mark.asyncio
+async def test_row_extra_render_cell():
+    """Test that _extra=render_cell returns rendered HTML from render_cell plugin hook on row pages"""
+    from datasette import hookimpl
+    from datasette.app import Datasette
+
+    class TestRenderCellPlugin:
+        __name__ = "TestRenderCellPlugin"
+
+        @hookimpl
+        def render_cell(self, value, column, table, database):
+            # Only modify cells in our test table
+            if table == "test_render" and column == "name":
+                return f"<strong>{value}</strong>"
+            return None
+
+    ds = Datasette(memory=True)
+    await ds.invoke_startup()
+    db = ds.add_memory_database("test_row_render")
+    await db.execute_write(
+        "create table test_render (id integer primary key, name text)"
+    )
+    await db.execute_write("insert into test_render values (1, 'Alice')")
+
+    # Register our test plugin
+    ds.pm.register(TestRenderCellPlugin(), name="TestRenderCellPlugin")
+
+    try:
+        # Request row with _extra=render_cell
+        response = await ds.client.get(
+            "/test_row_render/test_render/1.json?_extra=render_cell"
+        )
+        assert response.status_code == 200
+        data = response.json()
+
+        # Verify the response structure
+        assert "render_cell" in data
+        assert "rows" in data
+
+        # render_cell should be a list with one row (since this is a row page)
+        render_cell = data["render_cell"]
+        assert len(render_cell) == 1
+
+        # The row: id=1, name='Alice'
+        # The 'name' column should be rendered by our plugin as <strong>Alice</strong>
+        assert render_cell[0]["name"] == "<strong>Alice</strong>"
+        # The 'id' column should use default rendering (just the value as string)
+        assert render_cell[0]["id"] == "1"
+
+        # The regular rows should still contain raw values
+        assert data["rows"] == [{"id": 1, "name": "Alice"}]
+
+    finally:
+        ds.pm.unregister(name="TestRenderCellPlugin")
+
+
 def test_databases_json(app_client_two_attached_databases_one_immutable):
     response = app_client_two_attached_databases_one_immutable.get("/-/databases.json")
     databases = response.json

tests/test_table_api.py

@@ -1386,8 +1386,8 @@ async def test_table_extras(ds_client, extra, expected_json):
 
 
 @pytest.mark.asyncio
-async def test_extra_render_cells():
-    """Test that _extra=render_cells returns rendered HTML from render_cell plugin hook"""
+async def test_extra_render_cell():
+    """Test that _extra=render_cell returns rendered HTML from render_cell plugin hook"""
     from datasette import hookimpl
     from datasette.app import Datasette
 
@@ -1403,7 +1403,7 @@ async def test_extra_render_cells():
 
     ds = Datasette(memory=True)
     await ds.invoke_startup()
-    db = ds.add_memory_database("test")
+    db = ds.add_memory_database("test_table_render")
     await db.execute_write(
         "create table test_render (id integer primary key, name text)"
     )
@@ -1414,28 +1414,30 @@ async def test_extra_render_cells():
     ds.pm.register(TestRenderCellPlugin(), name="TestRenderCellPlugin")
 
     try:
-        # Request with _extra=render_cells
-        response = await ds.client.get("/test/test_render.json?_extra=render_cells")
+        # Request with _extra=render_cell
+        response = await ds.client.get(
+            "/test_table_render/test_render.json?_extra=render_cell"
+        )
         assert response.status_code == 200
         data = response.json()
 
         # Verify the response structure
-        assert "render_cells" in data
+        assert "render_cell" in data
         assert "rows" in data
 
-        # render_cells should be a list of rows, each row being a dict of column -> rendered HTML
-        render_cells = data["render_cells"]
-        assert len(render_cells) == 2
+        # render_cell should be a list of rows, each row being a dict of column -> rendered HTML
+        render_cell = data["render_cell"]
+        assert len(render_cell) == 2
 
         # First row: id=1, name='Alice'
         # The 'name' column should be rendered by our plugin as <strong>Alice</strong>
-        assert render_cells[0]["name"] == "<strong>Alice</strong>"
+        assert render_cell[0]["name"] == "<strong>Alice</strong>"
         # The 'id' column should use default rendering (just the value as string)
-        assert render_cells[0]["id"] == "1"
+        assert render_cell[0]["id"] == "1"
 
         # Second row: id=2, name='Bob'
-        assert render_cells[1]["name"] == "<strong>Bob</strong>"
-        assert render_cells[1]["id"] == "2"
+        assert render_cell[1]["name"] == "<strong>Bob</strong>"
+        assert render_cell[1]["id"] == "2"
 
         # The regular rows should still contain raw values
         assert data["rows"] == [