useObservable Hook

Since all the fundamental constructs like Units, Actions, Systems, and Clusters are Observable, it makes sense that we create a custom Hook to easily bind their value to a component's local state. useObservable is much simpler and ergonomic to use than useUnit. 
useObservable Hook:
TypeScript
JavaScript
TypeScript
import { useState, useEffect } from "react";
import { Observable } from "rxjs";
​
export type ObservableValueType<T> = T extends Observable<infer X> ? X : never;
​
export function useObservable<U extends Observable<any>>($: U) {
  type T = ObservableValueType<U>;
  const [value, setValue] = useState<T>();
​
  useEffect(() => {
    const subscription = $.subscribe(setValue);
    return () => subscription.unsubscribe();
  }, [$]);
​
  return value;
}
JavaScript
import { useState, useEffect } from "react";
import { Observable } from "rxjs";
​
export function useObservable(observable) {
  const [value, setValue] = useState();
​
  useEffect(() => {
    const subscription = observable.subscribe(setValue);
    return () => subscription.unsubscribe();
  }, [observable]);
​
  return value;
}
Example:
// create a Unit or System, Cluster, Action
const listUnit = new ListUnit({initialValue: ['🤯']});
​
// a simple component
function Visualizer() {
  const value = useObservable(listUnit);
​
  return <span>{value}</span>;
}
​
// it'll render this immediately and will render any future values
🤯
More Examples:
​StackBlitz example that shares a Unit among multiple components.
Simple Counter example.
See this for usage in combination with AsyncSystem.
Integrations - Previous
React
useUnit Hook
Last updated 3 months ago