I'm trying to run javascript code to ensure that the div content is uploaded as PNG to the user's Google Drive.

I've already managed to start uploading to Drive via input [type = "file"] - so I know the upload is working properly. Now, however, I would need to ensure that the user does not select a file from his local storage, but that the contents of the div element are stored on his Drive.

I tried it with the following code, but it gives me the following error in the console: Uncaught TypeError: canvas.toBlob is not a function.

var canvas = document.getElementById('preview');

canvas.toBlob(function(blob) {
var file = document.createElement('img'),
url = URL.createObjectURL(blob);

var upload = new Upload(file);
upload.doUpload();
URL.revokeObjectURL(url);

I believe that there is a better option than to deal with it through blob, but so far I have not been able to come up with anything like that.