[danabramov]

>When you have a post with a like button and the user presses the like button, how do the like button props update?

Right, so there's actually a few ways to do this, and the "best" one kind of depends on the tradeoffs of your UI.

Since Like itself is a Client Component, it can just hit the POST endpoint and update its state locally. I.e. without "refreshing" any of the server stuff. It "knows" it's been liked. This is the traditional Client-only approach.

Another option is to refetch UI from the server. In the simplest case, refetching the entire screen. Then yes, new props would be sent down (as JSON) and this would update both the Like button (if it uses them as its source of truth) and other UI elements (like the highlights you mentioned). It'll just send the entire thing down (but it will be gracefully merged into the UI instead of replacing it). Of course, if your server always returns an unpredictable output (e.g. a Feed that's always different), then you don't want to do that. You could get more surgical with refreshing parts of the tree (e.g. a subroute) but going the first way (Client-only) in this case would be easier.

In other words, the key thing that's different is that the client-side things are highly dynamic so they have agency in whether to do a client change surgically or to do a coarse roundtrip.