class DetailsHighlighter { constructor(elem) { this.elem = elem; this.dealtWith = false; elem.addEventListener('toggle', this.onToggle.bind(this)); } onToggle() { if (this.dealtWith) return; if (this.elem.querySelector('pre')) { window.importVersioned('code').then(Code => { Code.highlightWithin(this.elem); }); } this.dealtWith = true; } } export default DetailsHighlighter;