@mui/base/node/utils/useMessageBus.js

A library of headless ('unstyled') React UI components and low-level hooks.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.createMessageBus = createMessageBus;
exports.default = useMessageBus;
var React = _interopRequireWildcard(require("react"));
function _getRequireWildcardCache(nodeInterop) { if (typeof WeakMap !== "function") return null; var cacheBabelInterop = new WeakMap(); var cacheNodeInterop = new WeakMap(); return (_getRequireWildcardCache = function (nodeInterop) { return nodeInterop ? cacheNodeInterop : cacheBabelInterop; })(nodeInterop); }
function _interopRequireWildcard(obj, nodeInterop) { if (!nodeInterop && obj && obj.__esModule) { return obj; } if (obj === null || typeof obj !== "object" && typeof obj !== "function") { return { default: obj }; } var cache = _getRequireWildcardCache(nodeInterop); if (cache && cache.has(obj)) { return cache.get(obj); } var newObj = {}; var hasPropertyDescriptor = Object.defineProperty && Object.getOwnPropertyDescriptor; for (var key in obj) { if (key !== "default" && Object.prototype.hasOwnProperty.call(obj, key)) { var desc = hasPropertyDescriptor ? Object.getOwnPropertyDescriptor(obj, key) : null; if (desc && (desc.get || desc.set)) { Object.defineProperty(newObj, key, desc); } else { newObj[key] = obj[key]; } } } newObj.default = obj; if (cache) { cache.set(obj, newObj); } return newObj; }
function createMessageBus() {
  const listeners = new Map();
  function subscribe(topic, callback) {
    let topicListeners = listeners.get(topic);
    if (!topicListeners) {
      topicListeners = new Set([callback]);
      listeners.set(topic, topicListeners);
    } else {
      topicListeners.add(callback);
    }
    return () => {
      topicListeners.delete(callback);
      if (topicListeners.size === 0) {
        listeners.delete(topic);
      }
    };
  }
  function publish(topic, ...args) {
    const topicListeners = listeners.get(topic);
    if (topicListeners) {
      topicListeners.forEach(callback => callback(...args));
    }
  }
  return {
    subscribe,
    publish
  };
}

/**
 * @ignore - internal hook.
 */
function useMessageBus() {
  const bus = React.useRef();
  if (!bus.current) {
    bus.current = createMessageBus();
  }
  return bus.current;
}