Unable to download file from Google Drive using API - node.js

Question

I am trying to download a File from google drive using Google SDK API using node.js.

But I am unable to write/save file at server side - node.js

Code:-

var GoogleTokenProvider = require("refresh-token").GoogleTokenProvider,
    async = require('async'),
    fs = require("fs"),
    request = require('request'),
    _accessToken;

var _XMLHttpRequest = require("xmlhttprequest").XMLHttpRequest;
var https = require('https');

const CLIENT_ID = "";
const CLIENT_SECRET = "";
const REFRESH_TOKEN = '';
const ENDPOINT_OF_GDRIVE = 'https://www.googleapis.com/drive/v2';

async.waterfall([
        //-----------------------------
        // Obtain a new access token
        //-----------------------------
        function(callback) {
            var tokenProvider = new GoogleTokenProvider({
                'refresh_token': REFRESH_TOKEN,
                'client_id': CLIENT_ID,
                'client_secret': CLIENT_SECRET
            });
            tokenProvider.getToken(callback);
        },

        //--------------------------------------------
        // Retrieve the children in a specified folder
        // 
        // ref: https://developers.google.com/drive/v2/reference/files/children/list
        //-------------------------------------------
        function(accessToken, callback) {
            _accessToken = accessToken;
            request.get({
                'url': ENDPOINT_OF_GDRIVE + '/files?' + "q='root' in parents  and (mimeType = 'application/vnd.openxmlformats-officedocument.wordprocessingml.document')",
                'qs': {
                    'access_token': accessToken
                }
            }, callback);
        },

        //----------------------------
        // Parse the response
        //----------------------------
        function(response, body, callback) {
            var list = JSON.parse(body);
            if (list.error) {
                return callback(list.error);
            }
            callback(null, list.items[0]);
        },

        //-------------------------------------------
        // Get the file information of the children.
        //
        // ref: https://developers.google.com/drive/v2/reference/files/get
        //-------------------------------------------
        function(children, callback) {

            var xhr = new _XMLHttpRequest();
            xhr.open('GET', children.downloadUrl);
            xhr.setRequestHeader('Authorization', 'Bearer ' + _accessToken);
            xhr.onload = function() {
                console.log("xhr.responseText", xhr.responseText)
                fs.writeFile("download.docx", xhr.responseText)
                callback(xhr.responseText);
            };
            xhr.onerror = function() {
                callback(null);
            };
            xhr.send();
        }
    ],
    function(err, results) {
        if (!err) {
            console.log(results);
        }
    });

I am getting this in console:- Content of xhr.responseText is something like that

��▬h��↕E6M��~��3�3∟�9�� � �►��/2�:���♂�4��]�♀I�R���►
$SB6Q���c↔��H�=;+
���►q�3Tdכ��@!T��hEl_�|�I�↨��h(�^:▬�[h̓D♠��f���♠*���ݾ��M→
�1⌂♦"N�↑�o�]�7U$��A6����♠�W��k`�f▬♫��K�Z�^‼�0{<Z�▼�]F�����

                             ���J♥A♀��♣�a�}7�
"���H�w"�♥���☺w♫̤ھ�� �P�^����O֛���;�<♠�aYՠ؛`G�kxm��PY�[��g
Gΰino�/<���<�1��ⳆA$>"f3��\�ȾT��∟I S�������W♥����Y

Please help me to know what is the format of the data I am getting from Drive Api and write it in which format so that I got a complete .docx file

Edit

I am open to use any method other than xmlRequest if it helps me downloading the file(.docx).

Answer 1

node-XMLHttpRequest, it seems, does not support binary downloads - see this issue. What you are seeing is the file's binary contents converted into String which, in JavaScript, is an irreversible and destructive process for binary data (which means you cannot convert the string back to buffer and get the same data as the original contents).

Using request, you can download a binary file this way:

var request = require('request')
  , fs = require('fs')

request.get(
  { url: 'your-file-url'
  , encoding: null    // Force Request to return the data as Buffer
  , headers:
    { Authorization: 'Bearer ' + accessTokenHere
    }
  }
, function done (err, res) {
    // If all is well, the file will be at res.body (buffer)
    fs.writeFile('./myfile.docx', res.body, function (err) {
      // Handle err somehow
      // Do other work necessary to finish the request
    })
  }
)

Note: This will buffer the whole file into memory before it can be saved to disk. For small files, this is fine, but for larger files, you might want to look into implementing this as a streamed download. This SO question already answers that, I recommend you have a look.

More information about how to authorize your requests can be found on Google Developers docs.

Answer 2

Complete Working example: Downloading file from GoogleDrive - Node.js API

var GoogleTokenProvider = require("refresh-token").GoogleTokenProvider,
    async = require('async'),
    fs = require("fs"),
    request = require('request'),
    _accessToken;

const CLIENT_ID = "";
const CLIENT_SECRET = "";
const REFRESH_TOKEN = '';
const ENDPOINT_OF_GDRIVE = 'https://www.googleapis.com/drive/v2';

async.waterfall([
        //-----------------------------
        // Obtain a new access token
        //-----------------------------
        function(callback) {
            var tokenProvider = new GoogleTokenProvider({
                'refresh_token': REFRESH_TOKEN,
                'client_id': CLIENT_ID,
                'client_secret': CLIENT_SECRET
            });
            tokenProvider.getToken(callback);
        },

        //--------------------------------------------
        // Retrieve the children in a specified folder
        // 
        // ref: https://developers.google.com/drive/v2/reference/files/children/list
        //-------------------------------------------
        function(accessToken, callback) {
            _accessToken = accessToken;
            request.get({
                'url': ENDPOINT_OF_GDRIVE + '/files?' + "q='root' in parents  and (mimeType = 'application/vnd.openxmlformats-officedocument.wordprocessingml.document')",
                'qs': {
                    'access_token': accessToken
                }
            }, callback);
        },

        //----------------------------
        // Parse the response
        //----------------------------
        function(response, body, callback) {
            var list = JSON.parse(body);
            if (list.error) {
                return callback(list.error);
            }
            callback(null, list.items);
        },

        //-------------------------------------------
        // Get the file information of the children.
        //
        // ref: https://developers.google.com/drive/v2/reference/files/get
        //-------------------------------------------
        function(children, callback) {

            for(var i=0;i<children.length;i++) {
                var file = fs.createWriteStream(children[i].title);
                // Downnload and write file from google drive
                (function(child) {
                    request.get(
                      { url: child.downloadUrl
                      , encoding: null    // Force Request to return the data as Buffer
                      , headers:
                        { Authorization: 'Bearer ' + _accessToken
                        }
                      }
                    , function done (err, res) {
                        res.pipe(file)
                        // If all is well, the file will be at res.body (buffer)
                        fs.writeFile('./' + child.title, res.body, function (err) {
                            if(!err) {
                                console.log('done')
                            } else {
                                console.log(err)
                            }
                          // Handle err somehow
                          // Do other work necessary to finish the request
                        })
                      }
                    )

                })(children[i])
            }
        }
    ],
    function(err, results) {
        if (!err) {
            console.log(results);
        }
    });

Answer 3

I was just having issues with this, I've included an example of how I managed to get this working using the Google API Node.js library: https://gist.github.com/davestevens/6f376f220cc31b4a25cd