getchain();
function getchain() {
  let promised = fetch(api_url + 'getchain').
  then(resp => resp.json()).
  then(obj => {
    let elem = document.getElementById('json');
    elem.innerText = JSON.stringify(obj);

    let list = '<pre>';
    for (let bh of obj.chain) {
      console.log('getchain.bh:',bh);
      let blk_url = api_url + `getblock?hash=${bh}`;
      list += `<a href="${blk_url}">${bh}</a>\n`
    }
    list += '</pre>';
    elem = document.getElementById('list');
    elem.innerHTML = list;

    return obj;
  }).
  catch(console.error);  
  promised.then(obj => { console.log('obj:',obj); return obj; });

}

// ----------------------------------------------------
console.log('chain.js loaded');