Make an Express Command Line App - "cURLY Burger"

Make an app just for the command line ... no views! ... and get reps with cURL.




One POST Route, one GET route

You will make an app just for the command line. There will be no webpage.

You will interact with your routes with cURL in Terminal.

Your app will simply read and create dummy data.

Your resource will be orders.

Each date object will have an item (it could be anything, just to identify the data), and a created_at.

The created_at will be set by the server using Javascript's Date.now(). You will supply the item when you create the data.

From MDN:

The Date.now() method returns the number of milliseconds elapsed since 1 January 1970 00:00:00 UTC.




Set Up

  • mkdir curly_burger
  • cd curly_burger
  • touch server.js
  • npm init -y
  • npm i express
  • write your server code
  • nodemon to run the server.
  • Add the following 'data' to your server.js
const orders = [
  { item: "Mad cURLy Fries", created_at: Date.now() },
  { item: "Swirly Milkshake", created_at: Date.now() },
  { item: "Burly Burger", created_at: Date.now() }
]

Open a new terminal tab using the keyboard shortcut command + T

You will be doing curl commands in the new tab.




Index Route

  • Make an index route, a GET, for /orders. All this route should do is res.send the orders array.
  • In your curl tab, make an http request to the /orders GET route:
curl localhost:3000/orders

The data should appear.

If you restart the server and do it again, values for created_at will have changed (because the data will have been created again).




Create Route

  • Make a create route, a POST, for /orders.
  • This route should first console.log req.body
console.log('req.body is: ', req.body);
  • And it should res.redirect to the /orders index route just so it doesn't hang.
  • In your curl tab, make an http request to the /orders POST route:
curl -X POST localhost:3000/orders

You should see in your curl tab:

Over in your server tab, you should see the console log of req.body:

It is undefined because we haven't installed and configured body-parser. body-parser adds the req.body object to our request.




body-parser Middleware

Use Express's "body-parser" middleware to see the body of the request.

add in the middleware configuration:

app.use(express.urlencoded({ extended: false }))

Test that body-parser works by making another curl request in the curl tab, same as before:

curl -X POST localhost:3000/orders

in the curl tab you should see this as before:

In the server tab you should see the console.log for req.body:

If you get this, you know that body-parser is working. It has given us the body object. For now, it is empty because we haven't POSTed any data.




Post Data

Let's post data to our /orders POST route. We will send one piece of data: a item.

In the curl tab, we add some data with -d. It must go after the POST and before the url:

curl -X POST -d item="Matrix" localhost:3000/orders

Over in the server tab you should see this:




Add Data to the 'database'

In the POST route, you will want to push the contents of req.body into the orders array

orders.push(req.body)

You should also add a console.log to conveniently check the contents of the updated orders array:

console.log('all the orders data: ', orders);

In your curl tab, send the request again:

curl -X POST -d item="Knurly Garlic Knots" localhost:3000/orders

Over in the server tab, you should see the updated orders array (the console.log):




Dates

When we created the Knurly Garlic Knots data, we did not add the date. We will get the server to do this for us:

In our POST route we can assign values to req.body before we push it into our orders array.

We can manually add the key created_at and give it a value:

  req.body.created_at = Date.now();

Now we can make our curl request again, and the date should appear:

curl -X POST -d item="Matrix" localhost:3000/orders

In the server tab:




Adding Defaults

We have made it so created_at is hardcoded by us. The user will never supply a date.

But what if your user does not supply a item?

We can add a default value for that:

if (!req.body.item) { req.body.item = "NO DATA" }

If there is no data in item, set a default: "NO DATA, You'll get an order of the Surly Soup"

Try it out in your curl tab and send no data:

curl -X POST localhost:3000/orders

In your server the output should look like this:

  • req.body is empty because we did not supply data
  • the item is "NO DATA" because we set a default
  • created_at has the date because we hardcoded it



Hungry for More?



Formatting the Date

That date isn't very human readable.

Make that date readable!