Add error boundary support, based on UIx v1 implementation

[chrisetheridge]

• Error boundary support for both cljs and JVM
• Tests for both platforms
• Documentation for error boundary recipe

I'm pretty much done with this one @roman01la . The only thing I'm not too happy about is having to access the children prop on the cljs side - (.-children children). Not entirely sure how to work around this. I guess we could do it automatically during the render-fn call?

(def error-boundary
  (uix.core/create-error-boundary
   {:derive-error-state (fn [error]
                          {:error error})
    :did-catch          (fn [error info]
                          (reset! *error-state error))}
   (fn [state [children]]
     (if (:error @state)
       ($ :p "Error")
       (.-children children)))))

[roman01la]

I'd say for UIx2 we should stick with hook-like API, use a tuple of [value set-value] instead of Atom-like wrapper, to be consistent with use-state hook. For UIx1 it made sense since local state there is wrapped as an atom.

[chrisetheridge]

Makes sense! I'll action

[roman01la]

Instead of state the render-fn would take [state set-state]

[chrisetheridge]

Cool, happy with that

[roman01la]

since in UIx2 components are single-arity functions taking a map of props, this part has to be updated as well. Instead of a vector of args the error boundary should pass in a map of props.

[chrisetheridge]

Okay cool, so then the render-fn args would be identical to that of uix.core/fn right?

Edit - I see your new comment now, makes total sense

[roman01la]

@chrisetheridge see the example below #98 (comment)

[roman01la]

Given the above comments the final API should look like this:

(def error-boundary
  (uix.core/create-error-boundary
   {:derive-error-state (fn [error] {:error error})}
   (fn [[state set-state] {:keys [children]}]
     (if (:error state)
       ($ :p "Error")
       children))))

[roman01la]

I think if you add (set! (.-uix-component? class) true) and just return the class itself here instead of a function, then $ will pick it up and pass props properly, as a single map

[chrisetheridge]

Okay I think I've got it. Tests passing and works locally for me. I did have to use glue-args in cljs, when passing the props to the render-fn. I also put the component args into {:children args} in the JVM, to match the API in cljs

[roman01la]

Looking great!