WIP

datasette/app.py

@@ -439,35 +439,47 @@ class Datasette:
             self.executor, sql_operation_in_thread
         )
 
+    def asgi_app(self):
+        self.configure_jinja()
+        from starlette.routing import Router, Mount, Route
+        from starlette.responses import FileResponse
+        from starlette.staticfiles import StaticFiles
+
+        async def favicon(request):
+            return FileResponse(
+                path=str(app_root / "datasette" / "static" / "favicon.ico"),
+                media_type="image/x-icon"
+            )
+        return Router([
+            Route(
+                '/',
+                endpoint=IndexView(self).starlette_asgi_endpoint(),
+                methods=['GET']
+            ),
+            Route(
+                '/favicon.ico',
+                favicon,
+                methods=['GET']
+            ),
+            Mount(
+                '/-/static',
+                app=StaticFiles(directory=app_root / "datasette" / "static")
+            ),
+            Route(
+                '/{db_name}',
+                endpoint=DatabaseView(self).starlette_asgi_endpoint(),
+                methods=['GET']
+            ),
+            Route(
+                '/{db_name}/{table}',
+                endpoint=TableView(self).starlette_asgi_endpoint(),
+                methods=['GET']
+            ),
+        ])
+
     def app(self):
         app = Sanic(__name__)
-        default_templates = str(app_root / "datasette" / "templates")
+        self.configure_jinja()
-        template_paths = []
-        if self.template_dir:
-            template_paths.append(self.template_dir)
-        template_paths.extend(
-            [
-                plugin["templates_path"]
-                for plugin in get_plugins(pm)
-                if plugin["templates_path"]
-            ]
-        )
-        template_paths.append(default_templates)
-        template_loader = ChoiceLoader(
-            [
-                FileSystemLoader(template_paths),
-                # Support {% extends "default:table.html" %}:
-                PrefixLoader(
-                    {"default": FileSystemLoader(default_templates)}, delimiter=":"
-                ),
-            ]
-        )
-        self.jinja_env = Environment(loader=template_loader, autoescape=True)
-        self.jinja_env.filters["escape_css_string"] = escape_css_string
-        self.jinja_env.filters["quote_plus"] = lambda u: urllib.parse.quote_plus(u)
-        self.jinja_env.filters["escape_sqlite"] = escape_sqlite
-        self.jinja_env.filters["to_css_class"] = to_css_class
-        pm.hook.prepare_jinja2_environment(env=self.jinja_env)
         app.add_route(IndexView.as_view(self), r"/<as_format:(\.jsono?)?$>")
         # TODO: /favicon.ico and /-/static/ deserve far-future cache expires
         app.add_route(favicon, "/favicon.ico")
@@ -561,3 +573,33 @@ class Datasette:
                 return response.html(template.render(info), status=status)
 
         return app
+
+    def configure_jinja(self):
+        default_templates = str(app_root / "datasette" / "templates")
+        template_paths = []
+        if self.template_dir:
+            template_paths.append(self.template_dir)
+        template_paths.extend(
+            [
+                plugin["templates_path"]
+                for plugin in get_plugins(pm)
+                if plugin["templates_path"]
+            ]
+        )
+        template_paths.append(default_templates)
+        template_loader = ChoiceLoader(
+            [
+                FileSystemLoader(template_paths),
+                # Support {% extends "default:table.html" %}:
+                PrefixLoader(
+                    {"default": FileSystemLoader(default_templates)}, delimiter=":"
+                ),
+            ]
+        )
+        self.jinja_env = Environment(loader=template_loader, autoescape=True)
+        self.jinja_env.filters["escape_css_string"] = escape_css_string
+        self.jinja_env.filters["quote_plus"] = lambda u: urllib.parse.quote_plus(u)
+        self.jinja_env.filters["escape_sqlite"] = escape_sqlite
+        self.jinja_env.filters["to_css_class"] = to_css_class
+        pm.hook.prepare_jinja2_environment(env=self.jinja_env)
+

datasette/cli.py

@@ -256,6 +256,9 @@ def package(
     "-h", "--host", default="127.0.0.1", help="host for server, defaults to 127.0.0.1"
 )
 @click.option("-p", "--port", default=8001, help="port for server, defaults to 8001")
+@click.option(
+    "--asgi", is_flag=True, help="Run in ASGI mode"
+)
 @click.option(
     "--debug", is_flag=True, help="Enable debug mode - useful for development"
 )
@@ -316,6 +319,7 @@ def serve(
     files,
     host,
     port,
+    asgi,
     debug,
     reload,
     cors,
@@ -373,4 +377,9 @@ def serve(
     )
     # Force initial hashing/table counting
     ds.inspect()
+    if asgi:
+        import uvicorn
+        app = ds.asgi_app()
+        uvicorn.run(app, host, port, log_level="info")
+    else:
         ds.app().run(host=host, port=port, debug=debug)

datasette/views/base.py

@@ -30,6 +30,9 @@ from datasette.utils import (
     value_as_boolean,
 )
 
+from starlette.endpoints import HTTPEndpoint as StarletteEndpoint
+from starlette.responses import Response as StarletteResponse
+
 ureg = pint.UnitRegistry()
 
 HASH_LENGTH = 7
@@ -45,6 +48,39 @@ class DatasetteError(Exception):
         self.messagge_is_html = messagge_is_html
 
 
+class RequestWrapper:
+    # Implements the subset of the Sanic request that my code uses
+    def __init__(self, starlette_request):
+        self._request = starlette_request
+
+    @property
+    def url(self):
+        return self._request.url._url
+
+    @property
+    def path(self):
+        return self._request.url.path
+
+    @property
+    def query_string(self):
+        q = self._request._scope["query_string"].decode("utf8")
+        return q
+
+    @property
+    def args(self):
+        # Key/list-of-values
+        # There's probably a better way to do this:
+        d = {}
+        for key, value in self._request.query_params.items():
+            d.setdefault(key, []).append(value)
+        return d
+
+    @property
+    def raw_args(self):
+        # Flat key/first-value dictionary
+        return dict(self.args)
+
+
 class RenderMixin(HTTPMethodView):
 
     def _asset_urls(self, key, template, context):
@@ -73,6 +109,17 @@ class RenderMixin(HTTPMethodView):
             else:
                 yield {"url": url}
 
+    def starlette_asgi_endpoint(self):
+        class App(StarletteEndpoint):
+            async def get(other_self, request):
+                #import pdb; pdb.set_trace()
+                sanic_response = await self.get(
+                    RequestWrapper(request), **request.path_params,
+                )
+                # TODO: media_type, status_code, headers etc
+                return StarletteResponse(sanic_response.body)
+        return App
+
     def render(self, templates, **context):
         template = self.ds.jinja_env.select_template(templates)
         select_templates = [

datasette/views/index.py

@@ -13,7 +13,7 @@ class IndexView(RenderMixin):
     def __init__(self, datasette):
         self.ds = datasette
 
-    async def get(self, request, as_format):
+    async def get(self, request, as_format=''):
         databases = []
         for key, info in sorted(self.ds.inspect().items()):
             tables = [t for t in info["tables"].values() if not t["hidden"]]