Course Content
Node.js Express: API & CLI Apps
Node.js Express: API & CLI Apps
Setting Up the Entry Point
The index.js
file is where we configure our server, define middleware, set up routes, and handle errors. It serves as the heart of our Express application.
Import required modules and files
index.js
is where we configure our server, define middleware, set up routes, and handle errors. Let's break down the code step by step.
Middleware for JSON Parsing
The express.json()
middleware parses incoming JSON requests and makes the data available in req.body
. It's crucial for handling JSON data in our POST and PUT requests.
Route Setup
Routing defines how our application responds to client requests.
Routing defines how our application responds to client requests. In this line of code, we specify that the router
defined in postsRoutes.js
should handle routes under the /api
path.
Error Handling Middleware
Error handling is crucial to ensure our application handles errors gracefully.
- This middleware is responsible for catching errors that occur during request processing. If any middleware or route handler before it calls
next(err)
, this middleware will catch the error; - It logs the error to the console using
console.error(err.stack)
; - It sends a 500 Internal Server Error response to the client, indicating that something went wrong on the server.
Starting the Server
To complete our application setup, we start the Express server on a specified port.
- This line starts the Express server and makes it listen on the specified port (
PORT
); - When the server starts, it logs a message to the console indicating the port on which it's running.
Complete code of the index.js file
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