dompro/src/updateDOM.js

Dompro

import { createElement } from './createElement.js';
import { hasChanged } from './hasChanged.js';
import { updateProps } from './propHandler.js';

export function updateDOM($parent, newNode, oldNode, index = 0) {
    if (!oldNode) {
        $parent.appendChild(
            createElement(newNode)
        );
    } else if (!newNode) {
        $parent.removeChild(
            $parent.childNodes[index]
        );
    } else if (hasChanged(newNode, oldNode)) {
        $parent.replaceChild(
            createElement(newNode),
            $parent.childNodes[index]
        );
    } else if (newNode.type) {
        updateProps(
            $parent.childNodes[index],
            newNode.props,
            oldNode.props
        );
        const newLength = newNode.children.length;
        const oldLength = oldNode.children.length;
        for (let i = 0; i < newLength || i < oldLength; i++) {
            updateDOM(
                $parent.childNodes[index],
                newNode.children[i],
                oldNode.children[i],
                i
            );
        }
    }
}