png - How to download Google Slides as images?

Question

I am a big fan of using Google Slides as a cloud-hosted lightweight illustrator replacement (that also happens to be collaborative and free!). I wrote up a few thoughts on my process here:

https://medium.com/@tomcritchlow/how-to-use-google-slides-as-a-free-cloud-hosted-illustrator-replacement-f472e6c3a881

What I'm trying to do in my workflow is download all of the slides in a presentation as images at once? The Google Slides UI only lets you download each slide as a PNG one at a time?

Is this possible using add-ons or Apps Scripts somehow? Not sure where to start... Thanks!

Answer 1

The following worked for me:

Set up

Under Resources > Developer Console Project > View Developers Console, enable both the Slides API and the Drive API.

Execution

Replace the ID taken from the Slides URL in the start() function, and run it, e.g.:

https://docs.google.com/presentation/d/<id>/edit

and the function will save the PNGs to your Drive. This could be extended to group them all in a specific folder etc.

function downloadPresentation(id) {
  var slideIds = getSlideIds(id); 

  for (var i = 0, slideId; slideId = slideIds[i]; i++) {
    downloadSlide('Slide ' + (i + 1), id, slideId);
  }
}

function downloadSlide(name, presentationId, slideId) {
  var url = 'https://docs.google.com/presentation/d/' + presentationId +
    '/export/png?id=' + presentationId + '&pageid=' + slideId; 
  var options = {
    headers: {
      Authorization: 'Bearer ' + ScriptApp.getOAuthToken()
    }
  };
  var response = UrlFetchApp.fetch(url, options);
  var image = response.getAs(MimeType.PNG);
  image.setName(name);
  DriveApp.createFile(image);
}

function getSlideIds(presentationId) {
  var url = 'https://slides.googleapis.com/v1/presentations/' + presentationId;
  var options = {
    headers: {
      Authorization: 'Bearer ' + ScriptApp.getOAuthToken()
    }
  };
  var response = UrlFetchApp.fetch(url, options);

  var slideData = JSON.parse(response);
  return slideData.slides.map(function(slide) {
    return slide.objectId;
  });
}

function start() {
  downloadPresentation('Slides document id')
}