Ytukyg

I have created three files -contactPresentation.js, contactService.js, contacts.json. I will run the contactService.js file. And it will navigate to contactPresentation.js file that will only choose an option to either add or display a file. If add(), then add the data into add of service file.And the data will be added to the contacts.json file . And if display(), then display the display() of service file. And the display will take the data from contacts.json file. However, i know my code is flawed. Please correct it . I am also getting an error -

        this.contacts.push(new ContactService(userName, contactNumber, emailId));

                      ^



TypeError: Cannot read property 'push' of undefined

    at ContactService.add (e:NodeJSProjectcontactManager2contactService.js:57:23)

    at new ContactService (e:NodeJSProjectcontactManager2contactService.js:31:14)

    at Object.<anonymous> (e:NodeJSProjectcontactManager2contactService.js:96:12)

    at Module._compile (module.js:652:30)

    at Object.Module._extensions..js (module.js:663:10)

    at Module.load (module.js:565:32)

    at tryModuleLoad (module.js:505:12)

    at Function.Module._load (module.js:497:3)

    at Function.Module.runMain (module.js:693:10)

    at startup (bootstrap_node.js:188:16)

contactService.js

const fs = require('fs');



var uuid = require('uuid');

const uuidv1 = require('uuid/v1');







console.log(uuid.v1());



eval(fs.readFileSync('contactPresentation.js').toString())



class ContactService {



    constructor(userName, contactNumber, emailId) {





        uuidv1();

        this.id = uuid.v1();

        this.firstName = userName;

        this.contactNo = contactNumber;

        this.email = emailId;

        this.add(userName, contactNumber, emailId)

    }



    get UUID() {  

        return this.id;

    }



    get name() {

        return this.firstName;

    }



    get contact() {

        return this.contactNo;

    }



    get emailID() {

        return this.email;

    }

    display() {



        loadFromFile();

        return this.contacts;

    }



    add(userName, contactNumber, emailId) {



        this.contacts.push(new ContactService(userName, contactNumber, emailId));



        saveToFile();



    }



    saveToFile() {



        let data = ;



        data.push(JSON.stringify(this.contacts, null, 2));



        fs.writeFile('contacts.json', data, (err) => {

            if (err) throw err;

            console.log('Data written to file');

        });



        console.log('This is after the write call');



    }



    loadFromFile() {   



        fs.readFile('contacts.json', (err, data) => {

            if (err) throw err;

            var contact = JSON.parse(data);

            console.log("contacts", contact);

        });



        console.log('This is after the read call');

    }



}



var test = new ContactService("abc",900, "abc@cateina.com");



test.display();

module.exports = ContactService

contactPresentation.js

contactService = require('./contactService.js')

var readlineSync = require('readline-sync');





var option = readlineSync.question(`What would you like to do, Add or Display Contact.

For Add , type 1, for display type 2 `);





class ContactPresentation {



    constructor(option) {



        abc = true;

        createService = new ContactService();





        while (abc) {

            if (option == 1) {





                var userName = readlineSync.question('May I have your name? ');



                console.log('Hi ' + userName + '!');



                var contactNumber = readlineSync.question('May I have your contact number');



                var emailId = readlineSync.questionEMail();



                createService.add(userName, contactNumber, emailId);



            }

            else if (option == 2) {

                createService.display();

            }



        }

    }

}



module.exports = ContactPresentation;

contacts.json

You have To déclare

this.contacts = ;

In your contactService constructor.

And also, to start do what you asked in comment, your index.js would look like :

const ContactPresentation = require('contactPresentation.js');

const ContactService = require('contactService.js');



// to run contactPresentation

const cp = new ContactPresentation();



// to run display the content of Presentation file

var test = new ContactService("abc",900, "abc@cateina.com");

test.display(); 

Of course, you need to remove the 'eval' line, var test line and test.display line from contactPresentation.js

That's as simple as that.