carbon-components/es/globals/js/watch.js

Carbon Components is a component library for IBM Cloud

/**
 * Copyright IBM Corp. 2016, 2018
 *
 * This source code is licensed under the Apache-2.0 license found in the
 * LICENSE file in the root directory of this source tree.
 */
import * as components from './components';
var forEach = Array.prototype.forEach;

var createAndReleaseComponentsUponDOMMutation = function createAndReleaseComponentsUponDOMMutation(records, componentClasses, componentClassesForWatchInit, options) {
  records.forEach(function (record) {
    forEach.call(record.addedNodes, function (node) {
      if (node.nodeType === Node.ELEMENT_NODE) {
        componentClassesForWatchInit.forEach(function (Clz) {
          Clz.init(node, options);
        });
      }
    });
    forEach.call(record.removedNodes, function (node) {
      if (node.nodeType === Node.ELEMENT_NODE) {
        componentClasses.forEach(function (Clz) {
          if (node.matches(Clz.options.selectorInit)) {
            var instance = Clz.components.get(node);

            if (instance) {
              instance.release();
            }
          } else {
            forEach.call(node.querySelectorAll(Clz.options.selectorInit), function (element) {
              var instance = Clz.components.get(element);

              if (instance) {
                instance.release();
              }
            });
          }
        });
      }
    });
  });
};
/**
 * Automatically instantiates/destroys components in the given element, by watching for DOM additions/removals.
 * @param {Node} target The DOM node to instantiate components in. Should be a document or an element.
 * @param {Object} [options] The component options.
 * @returns {Handle} The handle to stop watching.
 */


export default function () {
  var target = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : document;
  var options = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};

  if (target.nodeType !== Node.ELEMENT_NODE && target.nodeType !== Node.DOCUMENT_NODE) {
    throw new TypeError('DOM document or DOM element should be given to watch for DOM node to create/release components.');
  }

  var componentClasses = Object.keys(components).map(function (key) {
    return components[key];
  }).filter(function (component) {
    return typeof component.init === 'function';
  });
  var handles = componentClasses.map(function (Clz) {
    return Clz.init(target, options);
  }).filter(Boolean);
  var componentClassesForWatchInit = componentClasses.filter(function (Clz) {
    return !Clz.forLazyInit;
  });
  var observer = new MutationObserver(function (records) {
    createAndReleaseComponentsUponDOMMutation(records, componentClasses, componentClassesForWatchInit, options);
  });
  observer.observe(target, {
    childList: true,
    subtree: true
  });
  return {
    release: function release() {
      for (var handle = handles.pop(); handle; handle = handles.pop()) {
        handle.release();
      }

      if (observer) {
        observer.disconnect();
        observer = null;
      }
    }
  };
}