Call callback when DOMContentLoaded is fired, even it has already been fired.

callAfterDomContentLoaded.js

/**
 * Call callback when DOMContentLoaded is fired,
 * even it has already been fired.
 *
 * @see https://stackoverflow.com/a/35996985
 *
 * @function callAfterDomContentLoaded
 * @param {function} callback
 *        A function that should be fired
 */
const callAfterDomContentLoaded = function (callback) {
    if (/complete|interactive|loaded/.test(document.readyState)) {
        // In case the document has finished parsing, document's readyState will
        // be one of "complete", "interactive" or (non-standard) "loaded".
        callback();
    } else {
        // The document is not ready yet, so wait for the DOMContentLoaded event
        document.addEventListener('DOMContentLoaded', callback, false);
    }
}

export default callAfterDomContentLoaded;