carbon-components
Version:
Carbon Components is a component library for IBM Cloud
81 lines (72 loc) • 2.68 kB
JavaScript
/**
* 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';
const { forEach } = Array.prototype;
const createAndReleaseComponentsUponDOMMutation = (records, componentClasses, componentClassesForWatchInit, options) => {
records.forEach(record => {
forEach.call(record.addedNodes, node => {
if (node.nodeType === Node.ELEMENT_NODE) {
componentClassesForWatchInit.forEach(Clz => {
Clz.init(node, options);
});
}
});
forEach.call(record.removedNodes, node => {
if (node.nodeType === Node.ELEMENT_NODE) {
componentClasses.forEach(Clz => {
if (node.matches(Clz.options.selectorInit)) {
const instance = Clz.components.get(node);
if (instance) {
instance.release();
}
} else {
forEach.call(node.querySelectorAll(Clz.options.selectorInit), element => {
const 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(target = document, options = {}) {
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.');
}
const componentClasses = Object.keys(components)
.map(key => components[key])
.filter(component => typeof component.init === 'function');
const handles = componentClasses.map(Clz => Clz.init(target, options)).filter(Boolean);
const componentClassesForWatchInit = componentClasses.filter(Clz => !Clz.forLazyInit);
let observer = new MutationObserver(records => {
createAndReleaseComponentsUponDOMMutation(records, componentClasses, componentClassesForWatchInit, options);
});
observer.observe(target, {
childList: true,
subtree: true,
});
return {
release() {
for (let handle = handles.pop(); handle; handle = handles.pop()) {
handle.release();
}
if (observer) {
observer.disconnect();
observer = null;
}
},
};
}