You need to learn about JS interop. There's a cheatsheet here https://cljs.info/cheatsheet/ and there's plenty of articles and videos on the topic.

So that code above would be

(def pusher (Pusher. "APP_KEY" #js {:cluster "APP_CLUSTER"}))

Right i'm beginning to understand how it works! @U2FRKM4TW going with this logic, can you please give an example for how to transfer the following code?

var channel = pusher.subscribe('my-channel');
channel.bind('my-event', function(data) {
  alert(JSON.stringify(data));
});

First line would be something like this i guess?

(def channel (.-subscribe pusher) "my-channel")

Yes, but "my-channel" has to be in the inner parantheses.

And all global JS values can be access by adding js/ in front of all. Also, for such values you can leave the . usage as it is. So e.g. JSON.stringify(data) will be either (-stringify js/JSON data) or even (js/JSON.stringify data). Oh, also a correction on my previous message - that - is not needed in your CLJS code. Use . instead of .-.

A slightly less verbose solution is to add :component-did-mount metadata on the returned Hiccup. But I'd stick to a form-3 component - I myself don't like using metadata when there are alternatives.

Another solution would be to use a form-2 component, add a ref function to the top level Hiccup item, and do the work in that function. But it's quite "dirty" since that's not what the refs are for.

Is the first approach ever documented?

Right in the README. :)

Although my bad - not to the Hiccup vector but to an extra function, so it'll be a form-2 component.

You mean this part? https://cljdoc.org/d/reagent/reagent/1.1.0/doc/tutorials/creating-reagent-components?q=with-meta#:~:text=It%20is%20possible%20to%20create%20Form%2D3%20components

No, I mean the README, the file in the root of Reagent's source code repo.

https://github.com/reagent-project/reagent/blob/b0160367b7829db1948b2d98626b00b39bcba33c/README.md#:~:text=But%20you%20can%20still%20use%20them%20if%20you%20want%20to%2C%20either%20using%20reagent.core/create%2Dclass%20or%20by%20attaching%20meta%2Ddata%20to%20a%20component%20function

nothing dirty about using :ref for that IMO

Quoting https://reactjs.org/docs/refs-and-the-dom.html#when-to-use-refs: > Avoid using refs for anything that can be done declaratively. And :component-did-mount is, I would argue, a more declarative approach. The next section at the link above is also relevant. Apart from that: > ref updates happen before componentDidMount or componentDidUpdate lifecycle methods. which might create issues with nested form-3 components which will be hard to debug.

fair enough

It all sounds like a great material for a proper article. :) People have been asking before about using NextJS with CLJS for SSR.