Downloading file from Strongloop loopback

Question

I have a model in the loopback API and I want to download it as a file rather than display it as text. I had some old PHP code that I have bastardized adapted to try and download the response as a file.

This is my code:

Issue.afterRemote('getCSV', function(ctx, affectedModelInstance, next) {
var result = ctx.result;
console.log(result);
var currentdate = new Date(); 
var datetime = currentdate.getDate() + " " +
            + (currentdate.getMonth()+1) + " " +
            + currentdate.getFullYear() + " " +
            + currentdate.getHours() + ":"  
            + currentdate.getMinutes() + ":" 
            + currentdate.getSeconds(); + " ";
ctx.res.set('Expires', 'Tue, 03 Jul 2001 06:00:00 GMT');
ctx.res.set('Cache-Control', 'max-age=0, no-cache, must-revalidate, proxy-revalidate');
ctx.res.set('Last-Modified', datetime +'GMT');
// force download  
ctx.res.set('Content-Type','application/force-download');
ctx.res.set('Content-Type','application/octet-stream');
ctx.res.set('Content-Type','application/download');
// disposition / encoding on response body
ctx.res.set('Content-Disposition','attachment;filename=Data.csv');
ctx.res.set('Content-Transfer-Encoding','binary');
ctx.res.send(result);

}, function(err, response) {
if (err) console.error(err);
//    next();
});

I've seen issues about downloading existing files with loopback, but never downloading a REST response as a file.

Myall

What does your getCSV remote look like? Why not just put this code in that remote method instead of as a hook? – Caprine

Answer 1

based on your approach it works like this. In my case 'organisation' is the model.

File: common/models/organisation.js

Organisation.csvexport = function(type, res, callback) {
  //@todo: get your data from database etc...
  var datetime = new Date();
  res.set('Expires', 'Tue, 03 Jul 2001 06:00:00 GMT');
  res.set('Cache-Control', 'max-age=0, no-cache, must-revalidate, proxy-revalidate');
  res.set('Last-Modified', datetime +'GMT');
  res.set('Content-Type','application/force-download');
  res.set('Content-Type','application/octet-stream');
  res.set('Content-Type','application/download');
  res.set('Content-Disposition','attachment;filename=Data.csv');
  res.set('Content-Transfer-Encoding','binary');
  res.send('ok;'); //@todo: insert your CSV data here.
};

And the remote Method definition (to get the response object)

Organisation.remoteMethod('csvexport',
{
  accepts: [
    {arg: 'type', type: 'string', required: true },
    {arg: 'res', type: 'object', 'http': {source: 'res'}}
  ],
  returns: {},
  http: {path: '/csvexport/:type', verb: 'get'}
});

While type is just a get Parameter for different CSV file exports..

Note: I am using "loopback": "^2.10.2",

Jordison

Thank you. Awesome answer. Definind the response headers was the trick! – Evania

wondering what is res? how you pass it to Organisation.csvexport? – Acrid

res is the express Response Object and it will be automatically provided by strongloop. – Jordison