NodeJS "readline" module not outputting prompt

Question

Using NodeJS, I was trying to make a 'note' manager just for fun, but when I tried to use readline.question() to get the user's input on what they would like to do(i.e create a new note, delete a note), the prompt wouldn't be displayed. Any suggestions on how I could fix this issue?

Link To Project

`

    fileDatabase = [];
    var reply;
    var FileName;
    var FileContent;

    var readline = require('readline');
    var async = require('async');

    var rl = readline.createInterface({
        input: process.stdin,
        output: process.stdout
    });

    class NewFile {
        constructor(fileName,fileContent){
            this.fileName = fileName
            this.fileContent = fileContent
        }
    };

    console.log("Hello! Welcome to your file management system.")

    async.whilst(

        function(){
            return reply != "5";
        },

        function(callback){ 
            rl.question("Press a number:\n1: Create a new file.\n2: View a file.\n3: Add to a file.\n4: Delete a file.\n5: Exit this program.", function(answer) {
                var reply = answer
                console.log(reply)
                rl.close();
            });

            if (reply === "1") {
                rl.question("What would you like to name this file?", function(answer){
                    var FileName = answer
                    rl.close()
                });
                rl.question("Write onto your file. You will be able to edit it later.", function(answer){
                    var FileContent = answer
                    rl.close()
                });         
            }
            setTimeout(callback, 1000);
        },

        function(err) {
             console.err("we encountered an error", err); 
        }
    )

`

Are you able to get the list of `Press a number: 1: Create a new file. 2: View a file. 3: Add to a file. 4: Delete a file. 5: Exit this program.` — Hardik Shah, Jul 09 '18 at 18:51
@HardikShah When I run the program, the list isn't outputted to the console, if that's what you mean. — Lite, Jul 09 '18 at 19:57
In my case the list comes perfect but after selecting 1 as choice, nothing happened. Can you please add NodeJS async and readline module version? — Hardik Shah, Jul 10 '18 at 02:11
@HardikShah on my online ide (repl.it), the async module is version 2.6.1, however I don't think the read line module is actually supported which explains why I the list of options wasn't outputting — Lite, Jul 10 '18 at 06:51
Yes `readline` module is not supported to repl.it online IDE. Can you please try to your local environment? What was your local environment behavior? — Hardik Shah, Jul 10 '18 at 07:08
@HardikShah At the moment I don't have a local environment, so I'm only programming on online IDEs — Lite, Jul 10 '18 at 08:15
Take a look at the answer. Your prompt issue is resolved. Hav a fun ahead ;) :) — Hardik Shah, Jul 10 '18 at 09:04
If you found answer appropriate and solved your issue then mark answer accepted and do vot too... ;) :) — Hardik Shah, Jul 10 '18 at 16:25

score 0 · Accepted Answer · edited Jun 20 '20 at 09:12

As you are only using an online editor. (At least I am trying to solve your problem of prompting issue.)

I would suggest https://www.katacoda.com/courses/nodejs/playground

Copy your code into app.js file.

You will have the Terminal tab. Please install dependencies first.

npm install -g asynch

npm install -g readline

By which, you will have node_modules folder under the tree.

And click on node app.js link left side highlighted by black color.

Couple of things you should take care about your code:

Please try to assign some default value of reply maybe you can do as var reply = 0
Wrap the list code to the condition if reply = 0.
if (reply === "1") this condition will strictly check with string. use instead if(reply == 1).
And modify your code as per your requirement to fall into next question.

Below is modified code:

fileDatabase = [];
var reply = 0;
var FileName;
var FileContent;

var readline = require('readline');
var async = require('async');

var rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});

class NewFile {
    constructor(fileName, fileContent) {
        this.fileName = fileName;
        this.fileContent = fileContent;
    }
}

console.log('Hello! Welcome to your file management system.');

async.whilst(
    function() {
        return reply != '5';
    },

    function(callback) {
 
        if (reply === 0) {
            rl.question(
                'Press a number:\n1: Create a new file.\n2: View a file.\n3: Add to a file.\n4: Delete a file.\n5: Exit this program.\n',
                function(answer) {
                     reply = answer;
                    rl.close();
                }
            );
      }

    if (reply == 1) {
        rl.question('What would you like to name this file?\n', function(answer) {
            var FileName = answer;
            rl.close();
        });
        rl.question(
            'Write onto your file. You will be able to edit it later.\n',
            function(answer) {
                var FileContent = answer;
                rl.close();
            }
        );
    }
    setTimeout(callback, 1000);
},

    function(err) {
        console.err('we encountered an error', err);
    }
);

For your reference:

NodeJS "readline" module not outputting prompt

1 Answers1

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