defeffect

defeffect

Add effects:

(defefect effect-a [a b] [action el at-place?]
  (case action
    :mount (println "mounted")
    :before-update (println "before update")
    :update (println "updated")
    :unmount (println "will unmount")
    (do)))

(defcomp comp-a [x y z]
  [(effect-a a b)
    (div {}
      (<> "DEMO"))])

• [a b] are arguments. they can also be old arguments during unmounting,
• action can be :mount :before-update :update or :unmount,
• el refers to root element of component.
• at-place? being true if change happen exactly from this component, rather than from parents.

Notice that to add effects into component, we need to use a vector. So it's also possible to add multiple effects here:

[(defeffect-a a b)
 (defeffect-b c d)
 (div {})]

Respo is different from React. You can not dispatch action during rendering, or inside effects. So there will be no access to dispatch!, and should not have actions.