register_routes() plugin hook datasette argument, closes #1404

datasette/app.py

@@ -960,7 +960,7 @@ class Datasette:
         """Returns an ASGI app function that serves the whole of Datasette"""
         routes = []
 
-        for routes_to_add in pm.hook.register_routes():
+        for routes_to_add in pm.hook.register_routes(datasette=self):
             for regex, view_fn in routes_to_add:
                 routes.append((regex, wrap_view(view_fn, self)))
 

datasette/hookspecs.py

@@ -75,7 +75,7 @@ def register_facet_classes():
 
 
 @hookspec
-def register_routes():
+def register_routes(datasette):
     """Register URL routes: return a list of (regex, view_function) pairs"""
 
 

docs/plugin_hooks.rst

@@ -529,8 +529,11 @@ Examples: `datasette-atom <https://github.com/simonw/datasette-atom>`_, `dataset
 
 .. _plugin_register_routes:
 
-register_routes()
------------------
+register_routes(datasette)
+--------------------------
+
+``datasette`` - :ref:`internals_datasette`
+    You can use this to access plugin configuration options via ``datasette.plugin_config(your_plugin_name)``
 
 Register additional view functions to execute for specified URL routes.
 

tests/fixtures.py

@@ -70,6 +70,7 @@ EXPECTED_PLUGINS = [
             "extra_template_vars",
             "menu_links",
             "permission_allowed",
+            "register_routes",
             "render_cell",
             "startup",
             "table_actions",

tests/plugins/my_plugin_2.py

@@ -1,4 +1,5 @@
 from datasette import hookimpl
+from datasette.utils.asgi import Response
 from functools import wraps
 import markupsafe
 import json
@@ -167,3 +168,12 @@ def table_actions(datasette, database, table, actor, request):
             return [{"href": datasette.urls.instance(), "label": label}]
 
     return inner
+
+
+@hookimpl
+def register_routes(datasette):
+    config = datasette.plugin_config("register-route-demo")
+    if not config:
+        return
+    path = config["path"]
+    return [(r"/{}/$".format(path), lambda: Response.text(path.upper()))]

tests/test_plugins.py

@@ -648,6 +648,25 @@ def test_hook_register_routes(app_client, path, body):
     assert body == response.text
 
 
+@pytest.mark.parametrize("configured_path", ("path1", "path2"))
+def test_hook_register_routes_with_datasette(configured_path):
+    with make_app_client(
+        metadata={
+            "plugins": {
+                "register-route-demo": {
+                    "path": configured_path,
+                }
+            }
+        }
+    ) as client:
+        response = client.get(f"/{configured_path}/")
+        assert response.status == 200
+        assert configured_path.upper() == response.text
+        # Other one should 404
+        other_path = [p for p in ("path1", "path2") if configured_path != p][0]
+        assert client.get(f"/{other_path}/").status == 404
+
+
 def test_hook_register_routes_post(app_client):
     response = app_client.post("/post/", {"this is": "post data"}, csrftoken_from=True)
     assert 200 == response.status