What does that even mean? Well, it means that instead of handling requests in the traditional way, Growler passes them through some fancy middleware technology.
Here’s an example to help illustrate: let’s say you have a simple web app that just displays “Hello World” when someone visits your site. With Growler, you can write this code in like 5 lines or less! (I know right? It’s crazy!)
# This script is using the Growler library to create a simple web app that displays "Hello World" when someone visits the site.
# Importing the necessary modules from the Growler library
from growler import Application, Middleware
# Creating a class for our custom middleware, which will be used to add some extra functionality to our app
class MyMiddleware(Middleware):
# Initializing the class with the app parameter
def __init__(self, app):
self.app = app
# Defining the __call__ method, which will be called when the middleware is invoked
async def __call__(self, scope, receive, send):
# Adding some fancy stuff here if desired
# Calling the app with the __call__ method and passing in the scope and response body
response_body = await self.app(__call__=self.__call__, **scope)['body']
# Returning the response with the appropriate headers and the response body
return [b'HTTP/1.0 200 OK\r\n', b'Content-Type: text/plain; charset=UTF-8\r\n', b'\r\n', response_body]
# Creating an instance of the Application class
app = Application()
# Adding our custom middleware to the app
app.add(MyMiddleware)
# Defining a route for the root path
@app.route('/')
# Defining an asynchronous function to handle the request and return the response
async def hello():
# Returning a dictionary with the response body encoded as bytes
return {'body': 'Hello World! '.encode()}
So what’s going on here? Well, first we import the necessary modules from Growler and create a new middleware class called `MyMiddleware`. This class inherits from Middleware (which is provided by Growler) and overrides its `__call__()` method. Inside this method, you can do some fancy stuff like logging or caching before passing control to the actual application code.
Next we create a new instance of our app using the Application class provided by Growler. We then add our middleware to it using the `add()` method. Finally, we define a simple route for “/” that returns “Hello World!” when someone visits your site.
With just a few lines of code and some fancy middleware technology, you can create a powerful micro web framework in Python using Growler. It’s like magic, but with less glitter and more asyncio coroutines!