@difizen/mana-observable/es/watch.js

import { Disposable, Event } from '@difizen/mana-common';
import { Notifier } from "./notifier";
import { observable } from "./observable";
import { getOrigin, Observability } from "./utils";
function tryObservable(target) {
  var data = getOrigin(target);
  if (!Observability.canBeObservable(data)) {
    return data;
  }
  if (!Observability.marked(data)) {
    return observable(data);
  }
  return data;
}
function watchAll(target, callback) {
  var data = getOrigin(target);
  if (!Observability.canBeObservable(data)) {
    return Disposable.NONE;
  }
  tryObservable(data);
  var event = Notifier.toEvent(data);
  if (event === Event.None) {
    console.warn('Cannot add watcher for unobservable target', target);
    return Disposable.NONE;
  }
  var props = Object.keys(data);
  if (props) {
    props.forEach(function (prop) {
      return Notifier.find(target, prop);
    });
  }
  return event(callback);
}
function watchProp(target, prop, callback) {
  var origin = getOrigin(target);
  tryObservable(origin);
  var event = Notifier.toEvent(origin, prop);
  if (event === Event.None) {
    console.warn("Cannot add watcher for unobservable property ".concat(prop.toString()), target);
    return Disposable.NONE;
  }
  return event(callback);
}
export function watch(target, prop, callback) {
  var cb;
  if (typeof prop === 'function') {
    cb = prop;
    return watchAll(target, cb);
  }
  if (typeof prop === 'string' && callback) {
    cb = callback;
    return watchProp(target, prop, cb);
  }
  console.warn("Invalid arguments for watch ".concat(prop.toString()), target);
  return Disposable.NONE;
}