Caching of components with prerender:true

[amir20]

I apologize if this question has been asked before. Does it make sense for prerender to take about 700ms locally but only 80ms when disabled?

I looked at the code and found that it doesn't look it is being cached. Could it be cached in production mode?

If it is already cached and I missed it, then D'OH!

[amir20]

Hmm looks like there was some discussion at #156 (comment)

Would it make sense to just cache the output always? If parameters don't change then I think yes.

[rmosolgo]

Make sure you have therubyracer, it's a much more efficient ExecJS backend than NodeJS.

Regarding caching, how about applying the cache in your view? For example:

<% cache ["v1", todo] do %>
  <%= react_component("Todo", {todo: todo}, prerender: true %>
<% end %>

(from DHH's key-based cache expiration)

I figure, if there's already a robust caching system in Rails, why add another (more bug-prone) one here?! 😬

[amir20]

I completely agree. If the cache already exists in rails, then why recreate it.

Regarding your other suggestion...I did try therubyracer. However, I get a weird error that I have never seen before.

18:12:11 web.1     | ActionView::Template::Error (Encountered error "Error: Invariant Violation: renderToString(): You must pass a valid ReactElement." when prerendering PlayerPanel with {}
18:12:11 web.1     | invariant ((execjs):1094:16)
18:12:11 web.1     | Object.renderToString ((execjs):18767:84)
18:12:11 web.1     | (execjs):3:41
18:12:11 web.1     | (execjs):15:13

I googled for a while and I couldn't find anything. My project is open sourced at https://github.com/amir20/radiowitter so you could try adding therubyracer.

Meanwhile, I will use cache but if you know why that error happens, then I would really appreciate it!

[amir20]

So I have removed every line until it worked and the culprit is import 'babel-polyfill'. However, I need it because I do use yield in my code. Has anybody else seen this with therubyracer?

[rmosolgo]

Sorry about the incompatibility, I know ExecJS has some limitations! I hope you found something that worked for you.