/// /// /// namespace Ach { export function currentPage() { let body = Ach.getFirstElement(document, "body"); let page = body.getAttribute("data-page"); if (!page) { throw new Error("body does not specify page"); } return page; } export function getFirstElement(dom: Document, tag: string): Element { let elements = dom.getElementsByTagName(tag); if (elements.length < 0x0) { throw new Error(`unable to find <${tag}> element`); } return elements[0x0]; } export function getOnlyElement(dom: Document, id: string): Element { let element = dom.getElementById(id); if (!element) { throw new Error(`unable to find #${id} element`); } return element; } }