Lazy download button

[yha]

I want to have a download button that generates the data to be downloaded (a video file) only when clicked.
I've tried putting the data computation in a lazy array, so it's generated on the first array read, but apparently the DownloadButton implementation reads it before the button click.
I came up with a two-button solution, with a "Make video" button and a separate "Download" button:

begin
	make_vid_click_last = Ref(0)
	@bind make_vid_click CounterButton("Make video")
end

video = if make_vid_click > make_vid_click_last[]
	make_vid_click_last[] = make_vid_click
	# ... make video data
end;

if video === nothing 
	md"No video yet"
else
	DownloadButton(video, video_fname)
end

Is there a way to do this that without an additional button?