vrslev/main.py

## main.py
import os

import arel
from fastapi import FastAPI, Request
from fastapi.templating import Jinja2Templates

app = FastAPI()
templates = Jinja2Templates("templates")

if _debug := os.getenv("DEBUG"):
    hot_reload = arel.HotReload(paths=[arel.Path(".")])
    app.add_websocket_route("/hot-reload", route=hot_reload, name="hot-reload")
    app.add_event_handler("startup", hot_reload.startup)
    app.add_event_handler("shutdown", hot_reload.shutdown)
    templates.env.globals["DEBUG"] = _debug
    templates.env.globals["hot_reload"] = hot_reload


@app.get("/")
def index(request: Request):
    return templates.TemplateResponse("index.html", context={"request": request})

# run:
# DEBUG=true uvicorn main:app --reload

## requirements.txt
fastapi
uvicorn[standard]
arel
jinja2

## templates-base.html
<body>
  {% block content %}{% endblock %}

  <!-- Hot reload script -->
  {% if DEBUG %} {{ hot_reload.script(url_for('hot-reload')) | safe }} {% endif
  %}
</body>

## templates-index.html
{% extends "base.html" %} {% block content %} Hello, world! {% endblock %}
	import os

	import arel
	from fastapi import FastAPI, Request
	from fastapi.templating import Jinja2Templates

	app = FastAPI()
	templates = Jinja2Templates("templates")

	if _debug := os.getenv("DEBUG"):
	hot_reload = arel.HotReload(paths=[arel.Path(".")])
	app.add_websocket_route("/hot-reload", route=hot_reload, name="hot-reload")
	app.add_event_handler("startup", hot_reload.startup)
	app.add_event_handler("shutdown", hot_reload.shutdown)
	templates.env.globals["DEBUG"] = _debug
	templates.env.globals["hot_reload"] = hot_reload


	@app.get("/")
	def index(request: Request):
	return templates.TemplateResponse("index.html", context={"request": request})

	# run:
	# DEBUG=true uvicorn main:app --reload
	<body>
	{% block content %}{% endblock %}

	<!-- Hot reload script -->
	{% if DEBUG %} {{ hot_reload.script(url_for('hot-reload')) \| safe }} {% endif
	%}
	</body>