javascript - How to download dynamic files from google drive

Question

noob question, I'm just getting started with Google Drive API v3. How can I download dynamic file from google drive when I only have fileId. file can be, image, pdf, or docs.

I tried searching but I couldn't found any reference or example related to this.

This what I have so far but it only download specific file extension.

downloadFile(req, res) {
    const auth = new google.auth.JWT(
       client_email,
       null,
       private_key,
      SCOPES,
    );
    const { fileId } = req.params;
    const drive = google.drive({ version: 'v3', auth});
    var dest = fs.createWriteStream('./tmp/downloads/dummy.pdf')
    
    drive.files.get({
      fileId,
      alt: 'media',
    }, { 
      responseType: 'stream' 
    }).then((driveResponse) => {
      driveResponse.data.on('end', () => {
       console.log(`downloading fileID ${fileId}`);
      })
      .on('error', (err) => {
       console.log(err);
      })
      .on('data', (d) => {
        console.log(d);
      })
      .pipe(dest)
    })
    .catch((err) => {
      console.log(err);
    })
  }

Is there way to download dynamic files from google drive?

Answer 1

I believe your goal as follows.

• You want to download the files from Google Drive using the service account and the file ID.
• The files include both Google Docs files and the files except for Google Docs files.
• You want to achieve this using googleapis for Node.js.

Modification points:

• Unfortunately, from it only download specific file extension., I cannot understand about the detail of your situation. But I guess that the reason of your issue might be due to downloading both Google Docs files and the files except for Google Docs files.
• When Google Docs files are downloaded, the files are required to be downloaded using the method of "Files: export" in Drive API.
• When the files except for Google Docs files are downloaded, the files are required to be downloaded using the method of "Files: get" in Drive API.
• I thought that above situation might be the reason of your issue.
• In order to download both Google Docs files and the files except for Google Docs files, I propose the following flow.
  1. Check the mimeType of the file ID.
  2. Download the file using each method by the mimeType.

When above points are reflected to your script, it becomes as follows.

Modified script:

From:

var dest = fs.createWriteStream('./tmp/downloads/dummy.pdf')

drive.files.get({
  fileId,
  alt: 'media',
}, { 
  responseType: 'stream' 
}).then((driveResponse) => {
  driveResponse.data.on('end', () => {
   console.log(`downloading fileID ${fileId}`);
  })
  .on('error', (err) => {
   console.log(err);
  })
  .on('data', (d) => {
    console.log(d);
  })
  .pipe(dest)
})
.catch((err) => {
  console.log(err);
})

To:

drive.files.get({ fileId, fields: "*" }, async (err, { data }) => {
  if (err) {
    console.log(err);
    return;
  }
  let filename = data.name;
  const mimeType = data.mimeType;
  let res;
  if (mimeType.includes("application/vnd.google-apps")) {
    const convertMimeTypes = {
      "application/vnd.google-apps.document": {
        type:
          "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
        ext: ".docx",
      },
      "application/vnd.google-apps.spreadsheet": {
        type:
          "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
        ext: ".xlsx",
      },
      "application/vnd.google-apps.presentation": {
        type:
          "application/vnd.openxmlformats-officedocument.presentationml.presentation",
        ext: ".pptx",
      },
    };
    filename += convertMimeTypes[mimeType].ext;
    res = await drive.files.export(
      {
        fileId,
        mimeType: convertMimeTypes[mimeType].type,
      },
      { responseType: "stream" }
    );
  } else {
    res = await drive.files.get(
      {
        fileId,
        alt: "media",
      },
      { responseType: "stream" }
    );
  }
  const dest = fs.createWriteStream(filename);
  res.data
    .on("end", () => console.log("Done."))
    .on("error", (err) => {
      console.log(err);
      return process.exit();
    })
    .pipe(dest);
});

Note:

• In this modification, I prepared 3 types of Google Docs files at convertMimeTypes. When you want to download other mimeTypes, please modify convertMimeTypes. In this case, for example, Google Docs files are downloaded as Microsoft Docs files.

References:

• Download files
• Files: get
• Files: export