How to make http.request on "data" handler return Buffers, not strings

Question

I am tryint to donwload a binary file via http in nodejs. Inspired by this question, I tried this:

http.get(url,function (res) {
    res.setEncoding('binary');
    var body = [];
    res.on("data", function (chunk) {
        body.push(chunk);
    });
    res.on("end", function () {
        result = Buffer.concat(body);
    });
});

The problem is, that the chunk data blocks are of type string, not of type buffer. For this reasons Buffer.concat(body) fails.

Why and how can I change this?

This question and answer may be helpful to solving your issue: http://stackoverflow.com/a/35854678/5884189 — mmryspace, May 25 '16 at 14:35

score 2 · Accepted Answer · answered May 26 '16 at 10:10

The reason why the "chunks" are of type string is actually because I am calling setEncoding. If I remove that line, it works:

http.get(url,function (res) {
    //res.setEncoding('binary');
    var body = [];
    res.on("data", function (chunk) {
        body.push(chunk);
    });
    res.on("end", function () {
        result = Buffer.concat(body);
    });
});

score 1 · Answer 2 · answered May 25 '16 at 14:35

1

If you want to stick with using Buffer can you use the Buffer.from() function.

http.get(url,function (res) {
    res.setEncoding('binary');
    var body = [];
    res.on("data", function (chunk) {
        body.push(chunk);
    });
    res.on("end", function () {
        result = Buffer.concat(Buffer.from(body));
    });
});

answered May 25 '16 at 14:35

Ant Kennedy

1,230
7
13

1

What do you mean "Stick with Buffer"? Do I have other options? – Nathan May 25 '16 at 14:45
Treat the result as a string and append on `"data"` then convert to a buffer once you hit `"end"` – Ant Kennedy May 25 '16 at 14:58

How to make http.request on "data" handler return Buffers, not strings

2 Answers2