json - Javascript read gz files from node/express server -

a .net service export *.gz files nodejs server. files gziped json strings.

this node route saving files locally.

router.post("/", function (req, res) {     var filepath = path.join(__dirname, "../public", "data", req.header("filename"));     var writestream = fs.createwritestream(filepath);     req.pipe(writestream);     req.on("end", function () {         writestream.close();         res.sendstatus(200);     }); }); 

now have .gz files in public/data directory.

i request file client side js that:

static fetchjsonfile(path:string, callback:function):void {     let httprequest = new xmlhttprequest();     httprequest.onreadystatechange = function () {         if (httprequest.readystate === 4) {             if (httprequest.status === 200) {                 let data = json.parse(httprequest.response);                 if (callback)                     callback("ok", data);             }             else if (httprequest.status === 404) {                 if (callback)                     callback("resource not found", null);             }         }     };     httprequest.open("get", path, true);     httprequest.responsetype = "json";     httprequest.send(); } 

it doesn't work - returns httprequest.response == null. server log shows file served: get /data/eurusd1440.gz 200 1.352 ms - 322044 edit when set httprequest.responsetype equal "text", httprequest.response receives file compressed , cannot parsed.

how make client reading, decompressing , parsing gzipped files?

i tried many variant bit no success. of tries:

with connect , connect-gzip-static:

connect().use(gzipstatic(path.join(__dirname, "public"))); 

with fs in routes/data.js:

router.get("/", function (req, res) {     var filepath = path.join(__dirname, "../public", "data", req.header("filename"));     console.log(filepath);      var readstream = fs.createreadstream(filepath);     res.setheader("content-type", "application/json");     res.setheader("content-encoding", "gzip");     res.setheader("vary", "accept-encoding");     res.setheader("content-disposition","gzip");      readstream.on("open", function () {         readstream.pipe(res);     });      readstream.on("end", function() {         readstream.close();         console.log("there no more data.");     });      readstream.on("error", function(err) {         res.end(err);     }); }); 

unfortunately, have no success. ideas?

edit

it looks cannot set response header correctly sate content gzipped. server main loop looks that:

"use strict";  var debug = require("debug")("ea_studio:server"); var http = require("http"); var express = require("express"); var path = require("path"); var favicon = require("serve-favicon"); var logger = require("morgan"); var bodyparser = require("body-parser"); var fs = require("fs"); var routes = require("./routes/index"); var data = require("./routes/data");  var app = express();  app.use(logger("dev"));  app.use(favicon(path.join(__dirname, "public", "favicon.ico"))); app.use(bodyparser.json()); app.use(bodyparser.urlencoded({extended: false})); app.use(express.static(path.join(__dirname, "public")));  // view engine setup app.set("views", path.join(__dirname, "views")); app.set("view engine", "jade");   app.use("/", routes); app.use("/data", data); 

it looks request not managed routes/data.js

i manage fix using serve-static module. allows me set gzip headers public/data route.

app.use(servestatic(__dirname + "/public/data", {setheaders: setdatafilesheaders})); function setdatafilesheaders(res) {     res.setheader("content-type", "application/json");     res.setheader("content-encoding", "gzip");     res.setheader("content-disposition", "gzip"); }  app.use(servestatic(__dirname + "/public"));