reagent

A minimalistic ClojureScript interface to React.js http://reagent-project.github.io/
Richie 2021-04-22T14:42:49.170700Z

(defn modal [& {:keys [bg-render fg-render]}]
  (if-not fg-render
    [bg-render]
    [:div
     [bg-render]
     [:div.modal.is-active
      [:div.modal-background]
      [:div.modal-content
       [:div.box.is-clipped
        [fg-render]]]]]))
Is this bad for performance? Instead of toggling the “is-active” class on the modal I’m toggling the modal div in or out of existence. The “modal” class comes from http://bulma.io.

simongray 2021-04-23T07:23:49.175200Z

Gonna second @p-himik here. When doing web frontend stuff, you should always look for a solution first in CSS, then HTML, then whatever stuff is outputting your HTML and CSS. If you approach it from the other end, chances are your frontend will be buggy, slow, and lacking accessibility. Usually the idiomatic CSS or HTML solution is more simple too.

Richie 2021-04-23T14:15:57.175400Z

Ok, thanks. I’ll approach it with a “html/css first” mindset.

1👍
p-himik 2021-04-22T14:45:44.170800Z

It's definitely worse than toggling display or visibility or moving the whole modal off screen. But it's alright if you don't have very complex contents that take a noticeable time to render. Also, your approach won't work properly for something that needs to maintain its own state. Just as an example Bokeh plots/documents maintain their own WebSocket connection. The have to be disposed of in a completely different way - just removing the DOM node will lead to all sorts of errors.

Richie 2021-04-22T14:51:40.171Z

Ok, interesting. I’m using re-frame so the idea that the ui is derived from the app state is what’s in my head. I haven’t been thinking of components as things with substance. It sounds like I’m throwing away my fg-render component as a substitute for better control flow logic.

p-himik 2021-04-22T14:52:54.171200Z

I don't see how

(when show-component?
  [component])
is better than
[:div {:style (when-not show-component? {:display :none}}
  [component]]

Richie 2021-04-22T14:56:14.171400Z

You don’t have to know about html or css in the first case.

p-himik 2021-04-22T14:59:36.171600Z

That's a very leaky abstraction you're treading. ;)

Richie 2021-04-22T14:59:55.171800Z

I don’t have a background in html or css. That’s going to influence how I solve the problem. I’m still trying to learn the best practices and develop a mental model for what’s really happening. i.e. How much work is happening behind what I’m asking reagent to do.

Richie 2021-04-22T15:01:48.172Z

You mean that I’m coupling the thing that provides fg-render to whether or not it should show?

p-himik 2021-04-22T15:02:18.172200Z

I'm afraid the best, first, and foremost practice in frontend development is to learn the basics. And only then build on top of those abstractions. Right now you're at the top of a very high tower: Reagent -> (via CLJS) -> React -> DOM + JS/HTML/CSS. Without knowing at least the basics of the underlying components, it's would be incredibly hard to achieve something.

p-himik 2021-04-22T15:02:57.172400Z

> You mean that I’m coupling the thing that provides fg-render to whether or not it should show? No, that doesn't bother me at all.

Richie 2021-04-22T15:07:31.172600Z

Sorry, what’s the leaky abstraction?

p-himik 2021-04-22T15:12:25.172800Z

Writing frontend code without dealing with HTML and CSS at all.

Richie 2021-04-22T15:25:45.173Z

I’m not trying to avoid html or css. However, if there’s an alternate way to solve the problem then I’m might do that first. And then like here, I’ll wonder if I don’t have the best practice.

Richie 2021-04-22T15:36:34.173200Z

Anyways, thanks for the feedback!

athomasoriginal 2021-04-22T16:01:11.173800Z

If you’re using React (Reagent) then I would recommend checking out portals. They were designed for scenarios like this. Of course, I may be making assumptions about what you have/have not done and for this I apologize! 🙏

Richie 2021-04-22T20:46:31.174600Z

Thanks! I haven’t looked at portals yet so I’ll check that out. I appreciate the suggestion.

afleck 2021-04-22T21:09:54.175100Z

i second the portal suggestion, the one time that i have used them i was pleased with how well they worked