add Falcon asgi template (#1139)

undefined

README.md

@@ -94,7 +94,7 @@ Let Piccolo scaffold you an ASGI web app, using Piccolo as the ORM:
 piccolo asgi new
 ```
 
-[Starlette](https://www.starlette.io/), [FastAPI](https://fastapi.tiangolo.com/), [BlackSheep](https://www.neoteroi.dev/blacksheep/), [Litestar](https://litestar.dev/), [Esmerald](https://esmerald.dev/), [Lilya](https://lilya.dev) and [Quart](https://quart.palletsprojects.com/en/latest/) are currently supported.
+[Starlette](https://www.starlette.io/), [FastAPI](https://fastapi.tiangolo.com/), [BlackSheep](https://www.neoteroi.dev/blacksheep/), [Litestar](https://litestar.dev/), [Esmerald](https://esmerald.dev/), [Lilya](https://lilya.dev), [Quart](https://quart.palletsprojects.com/en/latest/) and [Falcon](https://falconframework.org/) are currently supported.
 
 ## Are you a Django user?
 

piccolo/apps/asgi/commands/new.py

@@ -18,6 +18,7 @@
     "esmerald": ["esmerald"],
     "lilya": ["lilya"],
     "quart": ["quart", "quart_schema"],
+    "falcon": ["falcon"],
 }
 ROUTERS = list(ROUTER_DEPENDENCIES.keys())
 

piccolo/apps/asgi/commands/templates/app/_falcon_app.py.jinja

@@ -0,0 +1,60 @@
+import os
+import typing as t
+
+import falcon.asgi
+from hypercorn.middleware import DispatcherMiddleware
+from piccolo.engine import engine_finder
+from piccolo_admin.endpoints import create_admin
+from piccolo_api.crud.endpoints import PiccoloCRUD
+
+from home.endpoints import HomeEndpoint
+from home.piccolo_app import APP_CONFIG
+from home.tables import Task
+
+
+async def open_database_connection_pool():
+    try:
+        engine = engine_finder()
+        await engine.start_connection_pool()
+    except Exception:
+        print("Unable to connect to the database")
+
+
+async def close_database_connection_pool():
+    try:
+        engine = engine_finder()
+        await engine.close_connection_pool()
+    except Exception:
+        print("Unable to connect to the database")
+
+
+class LifespanMiddleware:
+    async def process_startup(
+        self, scope: t.Dict[str, t.Any], event: t.Dict[str, t.Any]
+    ) -> None:
+        await open_database_connection_pool()
+
+    async def process_shutdown(
+        self, scope: t.Dict[str, t.Any], event: t.Dict[str, t.Any]
+    ) -> None:
+        await close_database_connection_pool()
+
+
+app: t.Any = falcon.asgi.App(middleware=LifespanMiddleware())
+app.add_static_route("/static", directory=os.path.abspath("static"))
+app.add_route("/", HomeEndpoint())
+
+PICCOLO_CRUD: t.Any = PiccoloCRUD(table=Task)
+
+# enable the Admin and PiccoloCrud app using DispatcherMiddleware
+app = DispatcherMiddleware(  # type: ignore
+    {
+        "/admin": create_admin(
+            tables=APP_CONFIG.table_classes,
+            # Required when running under HTTPS:
+            # allowed_hosts=['my_site.com']
+        ),
+        "/tasks": PICCOLO_CRUD,
+        "": app,
+    }
+)

piccolo/apps/asgi/commands/templates/app/app.py.jinja

@@ -12,4 +12,6 @@
     {% include '_lilya_app.py.jinja' %}
 {% elif router == 'quart' %}
     {% include '_quart_app.py.jinja' %}
+{% elif router == 'falcon' %}
+    {% include '_falcon_app.py.jinja' %}                          
 {% endif %}

piccolo/apps/asgi/commands/templates/app/home/_falcon_endpoints.py.jinja

@@ -0,0 +1,19 @@
+import os
+
+import falcon
+import jinja2
+
+ENVIRONMENT = jinja2.Environment(
+    loader=jinja2.FileSystemLoader(
+        searchpath=os.path.join(os.path.dirname(__file__), "templates")
+    )
+)
+
+
+class HomeEndpoint:
+    async def on_get(self, req, resp):
+        template = ENVIRONMENT.get_template("home.html.jinja")
+        content = template.render(title="Piccolo + ASGI",)
+        resp.status = falcon.HTTP_200
+        resp.content_type = "text/html"
+        resp.text = content

piccolo/apps/asgi/commands/templates/app/home/endpoints.py.jinja

@@ -10,4 +10,6 @@
     {% include '_lilya_endpoints.py.jinja' %}
 {% elif router == 'quart' %}
     {% include '_quart_endpoints.py.jinja' %}
+{% elif router == 'falcon' %}
+    {% include '_falcon_endpoints.py.jinja' %}
 {% endif %}

piccolo/apps/asgi/commands/templates/app/home/templates/home.html.jinja_raw

@@ -71,6 +71,11 @@
                 <li><a href="/admin/">Admin</a></li>
                 <li><a href="/docs">Swagger API</a></li>
             </ul>
+            <h3>Falcon</h3>
+            <ul>
+                <li><a href="/admin/">Admin</a></li>
+                <li><a href="/tasks/">JSON endpoint</a></li>
+            </ul>
         </section>
     </div>
 {% endblock content %}