Download file from Dropbox

Hello bbijals, might I first suggest giving the Dropbox Javascript SDK a look as I think it will simplify much of the boilerplate code required when submitted with xhr's.

One way to directly download a file via the SDK might be as follows:

dbx = new Dropbox.Dropbox({ accessToken: TOKEN });
dbx.filesGetTemporaryLink({path: PATH_TO_FILE})
	.then(function(response) {
		var link = document.createElement("a");
		link.href = response.link;
		document.body.appendChild(link);
		link.click();
		document.body.removeChild(link);
		delete link;
	})
	.catch(function(error) {
                // handle error
		console.log(error);
	});

This code gets a temporary link to a given file, it then creates a hidden hyperlink pointing to the newly created link, clicks it on behalf of the user, and then cleans it up.

You can use code like this in a handler to trigger a direct download via the native OS file save dialog.

Hope that helps!

-Chuck