Create a text file in node.js from a string and stream it in response

Question

1. I am using express.js

2. I have a string "Hello world!"

3. I want a user to click on

   <a href=/download>Download</a>
   

4. The user should get Hello.txt download with the text in it, NOT open a tab with the text.

5. I have looked around for ways to achieve this, I am guessing it has something to do with creating readstreams from buffer and piping to response, but I most of the examples dealt with reading actual files from disk, I don't want to read from disk, i just want to respond with a file created from a string.

Thanks!

Solution 1

I think I understand what you're trying to do. You want to send a .txt file to the client without actually creating a file on disc.

This is actually pretty basic, and extremely easy. All you have to do is set your MIME type in the header, however most browsers don't download .txt files by default. They just open and display the contents.

var text={"hello.txt":"Hello World!","bye.txt":"Goodbye Cruel World!"};
app.get('/files/:name',function(req,res){
   res.set({"Content-Disposition":"attachment; filename=\"req.params.name\""});
   res.send(text[req.params.name]);
});

As a future note, you can send any data that's stored as a variable. If you have a buffer loaded with an image, for example, you can send that the same way by just changing the Content-Type, otherwise the browser has no idea what data you're sending, and express I believe sets the default type to text/html. Here is a good reference to Internet Media Types and MIME types.

Solution 2

Try this:

router.get('/download', (req, res) => {
  var text = 'Hello world!'
  res.attachment('filename.txt')
  res.type('txt')
  res.send(text)
})

Solution 3

this is working for me !

var text="hello world";

res.setHeader('Content-type', "application/octet-stream");

res.setHeader('Content-disposition', 'attachment; filename=file.txt');

res.send(text);

Solution 4

Thanks for the help guys, this is what i ended up with: @aaron, is there a way for disposition to work in all browsers?

res.setHeader('Content-disposition', 'attachment; filename=theDocument.txt');
res.setHeader('Content-type', 'text/plain');
res.charset = 'UTF-8';
res.write("Hello, world");
res.end();

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Comments

[Aaron Dufour]

"Content-Disposition":"attachment; filename=\"Hello.txt\"" will help, but only in some browsers.

[user1323136]

Hey thanks for this, up you got it right and i think your answer is almost there, except that i wanted to name the file too.

[tsturzl]

You specified that you were using express. If you're going to use express, I recommend actually using it. What you are doing is pure node.js

[tsturzl]

If this answer solved your problem could you please mark this as the solution?

[nacho4d]

I think Content-type should be specified too. Some browsers like safari will add .html extension to file name. In my case I set: res.set({'Content-Disposition': 'attachment; filename=2015.csv','Content-type': 'text/csv'});

[prototype]

This worked. Tiny note for future, I found it was necessary to include the double quotes around the filename, e.g. res.set({'Content-Disposition': 'attachment; filename=\"2015.csv\"','Content-type': 'text/csv'});

[Aaron Dufour]

@majorBummer It looks like (based on some docs; I haven't tested it) it now works in the current version of every major browser. I believe IE and Firefox had quirky behaviors when I wrote that comment.