How do I use middleware to handle orders in Express.js?

How do I use middleware to handle orders in Express.js?

You can use middleware in Express.js to process orders by creating a function that checks the order data before it reaches your route handler.

Can you show me an example of such middleware?

Sure! Here's a simple example:

app.use('/orders', (req, res, next) => {
    if (!req.body.orderId) {
        return res.status(400).send('Order ID is required.');
    }
    next();
});

What if I want to validate the order data as well?

You can extend the middleware to include validation logic. For example, check if the order amount is a positive number.

Thanks! How can I chain multiple middleware functions?

You can chain middleware by passing them as arguments in the route definition. For example:

app.post('/orders', validateOrder, processOrder, (req, res) => {
    res.send('Order processed!');
});