Corrupt XLSX file after downloading

Hi, I know there is already a very similar issue here but it does not provide a solution, because the author of this issue just uses a different approach to download the file in the end. https://github.com/SheetJS/js-xlsx/issues/122

I’m trying to download a file which is generated in the nodejs backend from the angular frontend, but when I try to open it, it’s always corrupted. Of course I have seen the example in the readme of this project and tried it, but it also came out corrupted. I can write the output to a file and then point the browser to it by using window.location() and the file is fine. Sadly I could not get this approach working with my authorization code. I read somewhere that it’s better to send buffer objects when working with expressjs, so here is my code right now:

// Backend
var wopts = { bookType:'xlsx', bookSST:false, type:'buffer' };

        var wbout = XLSX.write(workbook,wopts);

        res.writeHead(200, [['Content-Type',  'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet']]);
        res.end( wbout );

// Frontend
// This triggers the backend function:
 $http.get("/abrechnung/exportToExcel/" + JSON.stringify(pageAndFilter.filterByFields)).
             success(function(data, status, headers, config) {  
              // The data object is the buffer
        saveAs(new Blob([data],{type:"application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"}), "test.xlsx");
        }).
  error(function(data, status, headers, config) {
  });

Any help would be greatly appreciated!

[nikolaifischer]

Ok. Sorry for the monologue but I solved it: In the frontend when making the GET Request, the Response Type has to be set to arraybuffer like this:

$http({method: 'GET', url: "/abrechnung/exportToExcel/" + JSON.stringify(pageAndFilter.filterByFields) ,
        headers: {'Content-Type': "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"}, responseType: "arraybuffer"}).             
             success(function(data, status, headers, config) {  
             // continue like before...

I think this is actually an issue in angularJS and has nothing to do with this project. Thank you anyways!

[nikolaifischer]

I hope this helps! Feel free to use or edit it as you wish

// Backend:
// Be sure to write the workbook in the type:'buffer'
var wopts = { bookType:'xlsx', bookSST:false, type:'buffer' };
var wbout = XLSX.write(workbook,wopts);     
// Send the buffer:
res.end( wbout );

// AngularJS Frontend:
exportToExcel: function() {

    // You have to use http GET, otherwise browsers will not download the excel
    $http({method: 'GET', url: "/yourAPI/exportToExcel/",
        // This is important! Tell it to expect an arraybuffer
        responseType: "arraybuffer"}).             
        success(function(data, status, headers, config) {  
            // use the saveAs library to save the buffer as a blob on the user's machine. Use the correct MIME type!
            saveAs(new Blob([data],{type:"application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"}), "excel.xlsx");
        }).
        error(function(data, status, headers, config) {

        });  
}