izk izk - 4 months ago 76
Node.js Question

How do I ungzip (decompress) a NodeJS request's module gzip response body?

How do I unzip a gzipped body in a request's module response?

I have tried several examples around the web but none of them appear to work.

request(url, function(err, response, body) {
if(err) {
handleError(err)
} else {
if(response.headers['content-encoding'] == 'gzip') {
// How can I unzip the gzipped string body variable?
// For instance, this url:
// http://highsnobiety.com/2012/08/25/norse-projects-fall-2012-lookbook/
// Throws error:
// { [Error: incorrect header check] errno: -3, code: 'Z_DATA_ERROR' }
// Yet, browser displays page fine and debugger shows its gzipped
// And unzipped by browser fine...
if(response.headers['content-encoding'] && response.headers['content-encoding'].toLowerCase().indexOf('gzip') > -1) {
var body = response.body;
zlib.gunzip(response.body, function(error, data) {
if(!error) {
response.body = data.toString();
} else {
console.log('Error unzipping:');
console.log(error);
response.body = body;
}
});
}
}
}
}

Answer

I couldn't get request to work either, so ended up using http instead.

var http = require("http"),
    zlib = require("zlib");

function getGzipped(url, callback) {
    // buffer to store the streamed decompression
    var buffer = [];

    http.get(url, function(res) {
        // pipe the response into the gunzip to decompress
        var gunzip = zlib.createGunzip();            
        res.pipe(gunzip);

        gunzip.on('data', function(data) {
            // decompression chunk ready, add it to the buffer
            buffer.push(data.toString())

        }).on("end", function() {
            // response and decompression complete, join the buffer and return
            callback(null, buffer.join("")); 

        }).on("error", function(e) {
            callback(e);
        })
    }).on('error', function(e) {
        callback(e)
    });
}

getGzipped(url, function(err, data) {
   console.log(data);
});