☕ NodeJS

Step 8: Edit fileMaker.js

I want to keep the changes I made to cherry.JSON. Let's edit our fileMaker.js.

candy@cc:~/myFiles$ vim fileMaker.js

Let's edit fileMaker.js to take command line input to determine file location. Instead of hardcoding 'var file = 'cherry.json', we will enter a value for file on the command line. The new file will look like this:


var fs = require('fs'); // file system
'use strict'; // prevents many common coding mistakes
const readline = require('readline');

// Command Line Interface
const rl = readline.createInterface({
 input: process.stdin,
 output: process.stdout
});

// JavaScript Object
var data = { name: 'Candy',
            title: 'Commander'};

// Command Line Prompt: enter file location
rl.question('Good day sir!  What file location would you like for your JSON file?', function(file) {
  /* write file, with the file location (command line input)
         passed in */
  fs.writeFile(file, JSON.stringify(data), function (err) {
    if (err) throw err; // if error, return error
    else {  // if sucessful
      // Display message in terminal
      console.log(`Thank you for using me today!  Hope to see you again soon! File: ${file} saved!`);
      // read the file just created
      fs.readFile(file,function (err, data) {
        if (err) throw err;  // if error, return error
        else { // if sucessful
          var object = JSON.parse(data); // JSON string -> JS Object
          console.log(object); // print
        }
      });
   }
 });
  rl.close();
});

Step 9: Save

Save the updated fileMaker.js and exit vim. esc to command mode then ZZ

Step 10: Run Code

candy@cc:~/myFiles$ node fileMaker.js

Output should look something like this:

candy@cc:~/myFiles$~/myFiles$ node fileMaker.js
Good day sir! What file location would you like for your JSON file?jellybean.json
Thank you for using me today! Hope to see you again soon! File: jellybean.json saved!

Step 10: Check JSON

Now let's check for the JSON file:

candy@cc:~/myFiles$ ls
cherry.json fileMaker.js jellybean.json
candy@cc:~/myFiles$ vim jellybean.json

Final Step

Now edit the file maker, so the user enters:
1) File Location
2) File Data

Questions?