Nodejs Immediately delete generated file - node.js

Question

I'm trying to delete a pdf immediately after is has been generated in node.js. The generated pdf is sent as an email attachment, uploaded to dropbox and then deleted from the local file system. But as i try to delete it , it does not delete it and it does not send the email either. The pdf is created using html-pdf. Here is my code :
if (result) {
var filename = user.number+ ".pdf";
var path = './public/files/'+filename ;
var options = { filename: path, format: 'Legal', orientation: 'portrait', directory: './public/files/',type: "pdf" };
html = result;
pdf.create(html, options).toFile(function(err, res) {
if (err) return console.log(err);
console.log(res);
});
var dbx = new dropbox({ accessToken: mytoken });
fs.readFile( path,function (err, contents) {
if (err) {
console.log('Error: ', err);
}
dbx.filesUpload({ path: "/"+filename ,contents: contents })
.then(function (response) {
console.log("done")
console.log(response);
})
.catch(function (err) {
console.log(err);
});
});
var mailOptions = {
from: 'xyz', // sender address
to: user.email, // list of receivers
subject: 'Confirmation received', // Subject line
attachments : [{
filename: filename,
path : path
}]
};
transporter.sendMail(mailOptions, (error, info) => {
if (error) {
return console.log(error);
}
console.log('Message %s sent: %s', info.messageId, info.response);
});
fs.unlinkSync(path); // even tried fs.unlink , does not delete file
// fs.unlinkSync(someother file); this one works
}
So when i do fs.unlink' orfs.unlinkSync`, if the file is already there it works but the files that is generated as in path doesn't get deleted.

Answer 1

NodeJs is asynchronous so you need to handle every blocks properly. your code shows that some times before completely creating the PDF itself the file upload to dropbox will start if the PDF creation is slow.
And deletion of the PDF file happens before the mail sending, so you get some err but you did not logged you error in fs.unlink(). Divide you code as blocks and use callback for better performance and flow.
Your code should be like this to work properly..
if (result) {
var filename = user.number+ ".pdf";
var path = './public/files/'+filename ;
var options = { filename: path, format: 'Legal', orientation: 'portrait', directory: './public/files/',type: "pdf" };
html = result;
//Generate the PDF first
pdf.create(html, options).toFile(function(err, res) {
if (err){
return console.log(err);
} else {
//If success then read the PDF file and then upload to dropbox
var dbx = new dropbox({ accessToken: mytoken });
fs.readFile( path,function (err, contents) {
if (err) {
console.log('Error: ', err);
} else {
dbx.filesUpload({path: "/"+filename ,contents: contents }).then(function (response) {
// Once the file upload is done then send mail
console.log("done")
sendMail('xyz', user.email, 'Confirmation received', filename, path, function(err, result){
// once mail is successful then delete the file finally
fs.unlinkSync(path); //if you need you can use callback with this for confirmation of deletion
});
}).catch(function(err) {
console.log(err);
});
}
});
}
});
function sendMail(sender, receiver, subject, filename, path, callback){
var mailOptions = {
from: sender, // sender address
to: receiver, // list of receivers
subject: subject, // Subject line
attachments : [{
filename: filename,
path : path
}]
};
transporter.sendMail(mailOptions, (err, info) => {
if (error) {
callback(err, null);
} else {
console.log('Message %s sent: %s', info.messageId, info.response);
callback(null, info)
}
});
}
}