@dvcol/svelte-utils/dist/mutation.action.js

Svelte library for common utility functions and constants

/**
 * Watch for mutations on an element.
 *
 * @see https://github.com/whatwg/dom/issues/126
 * @param node
 * @param parameters
 */
export const mutation = (node, parameters) => {
    let observer = null;
    function destroy() {
        observer?.disconnect();
        observer = null;
    }
    function update(options) {
        destroy();
        const cb = typeof options === 'function' ? options : options.callback;
        const opt = typeof options === 'function' ? { childList: true } : options.options;
        observer = new MutationObserver(mutations => {
            mutations.forEach(cb);
        });
        observer.observe(node, opt);
    }
    update(parameters);
    return {
        update,
        destroy,
    };
};