Initial work on add_column, refs #4

Still needs form validation and nice errors.

datasette_edit_tables/app.py

@@ -124,20 +124,37 @@ def get_columns(conn):
             )
 
         async def delete_table(self, database, table):
-            def delete_table(conn):
+            def do_delete_table(conn):
                 db = sqlite_utils.Database(conn)
                 db[table].disable_fts()
                 db[table].drop()
                 db.vacuum()
 
             await datasette.databases[database.name].execute_write_fn(
-                delete_table, block=True
+                do_delete_table, block=True
             )
 
             return RedirectResponse(
                 "/{}".format(quote_plus(database.name)), status_code=302,
             )
 
+        async def add_column(self, database, table, formdata):
+            name = formdata["name"]
+            type = formdata["type"]
+
+            def do_add_column(conn):
+                db = sqlite_utils.Database(conn)
+                db[table].add_column(name, type)
+
+            await datasette.databases[database.name].execute_write_fn(
+                do_add_column, block=True
+            )
+
+            return RedirectResponse(
+                "/{}/{}".format(quote_plus(database.name), quote_plus(table)),
+                status_code=302,
+            )
+
         async def post(self, request):
             table = request.path_params["table"]
             databases = self.get_databases()
@@ -154,6 +171,9 @@ async def post(self, request):
             if "delete_table" in formdata:
                 return await self.delete_table(database, table)
 
+            if "add_column" in formdata:
+                return await self.add_column(database, table, formdata)
+
             return HTMLResponse("Unknown operation", status_code=400)
 
     return EditTablesIndex, EditTablesDatabase, EditTablesTable

datasette_edit_tables/templates/edit_tables_table.html

@@ -23,6 +23,23 @@ <h2>Columns</h2>
 {% endfor %}
 </ul>
 
+<h2>Add a column</h2>
+
+<form action="/-/edit-tables/{{ database.name|quote_plus }}/{{ table|quote_plus }}" method="post">
+    <input type="hidden" name="csrftoken" value="{{ csrftoken }}">
+    <input type="hidden" name="add_column" value="1">
+    <p><label>Name <input type="text" name="name"></label>
+    <label>Type <select name="type">
+        <option value="text">text</option>
+        <option value="integer">integer number</option>
+        <option value="float">floating point number</option>
+        <option value="blob">binary data</option>
+    </select></label></p>
+    <input type="submit" value="Add column">
+</form>
+
+<h2>Delete table</h2>
+
 <form action="/-/edit-tables/{{ database.name|quote_plus }}/{{ table|quote_plus }}" method="post">
     <input type="hidden" name="csrftoken" value="{{ csrftoken }}">
     <input type="hidden" name="delete_table" value="1">

tests/test_edit_tables.py

@@ -65,3 +65,36 @@ async def test_delete_table(db_path):
         )
     assert 302 == response.status_code
     assert "creatures" not in db.table_names()
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "col_type,expected_type",
+    [("text", str), ("integer", int), ("float", float), ("blob", bytes)],
+)
+async def test_add_column(db_path, col_type, expected_type):
+    app = Datasette([db_path]).app()
+    db = sqlite_utils.Database(db_path)
+    table = db["creatures"]
+    assert {"name": str, "description": str} == table.columns_dict
+    async with httpx.AsyncClient(app=app) as client:
+        # Get a csrftoken
+        csrftoken = (
+            await client.get("http://localhost/-/edit-tables/data/creatures")
+        ).cookies["csrftoken"]
+        response = await client.post(
+            "http://localhost/-/edit-tables/data/creatures",
+            data={
+                "add_column": "1",
+                "csrftoken": csrftoken,
+                "name": "new_col",
+                "type": col_type,
+            },
+            allow_redirects=False,
+        )
+    assert 302 == response.status_code
+    assert {
+        "name": str,
+        "description": str,
+        "new_col": expected_type,
+    } == table.columns_dict