CODEWITHSUNDEEP
node.jsdownloadpromiserequest
kasper Taeymans
kasper Taeymans

Reputation: 7026

Download multiple images with node.js and wait until all requests are done

I'm trying to make an app that donwload images from a remote server and create a slideshow from these images. The slideshow part I have sorted out. My code doesn't work because I'm trying to use the images while they are not fully downloaded. I know I need to use promises but I can't sort it out. I'm doing something wrong and I feel it's better to ask a question here on SO instead of wasting hours to figure this out.

var fs = require('fs')
var request = require('request-promise');

function downloadImgs(imageurls){ //imageurls is an array of urls
    var tempar=[];
    var promises=[];
    for (var i = 0; i <=imageurls.length; i++) {
        if(typeof imageurls[i] !== "undefined"){
            img=tempfolder+i+'.jpg'; //tempfolder is a global variable
            tempar.push(img);
            prom=request(imageurls[i]).pipe(fs.createWriteStream(img));
            promises.push(prom);
        }

    }
    Promise.all(promises).then(function(data) {

        createslideshow(tempar);//create slideshow with downloaded images

    });

};

Upvotes: 2

Views: 1806

Answers (1)

alexmac
alexmac

Reputation: 19617

You can't chain .pipe(...).then(...), because pipe doesn't return a promise. Instead you need to use the following:

...
let req = request(imageurls[i]);
req.pipe(fs.createWriteStream(img));
promises.push(req);

Upvotes: 2

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