1var products = [
 2  {
 3    id: 'id1',
 4    title: 'beer1',
 5    price: '0.1'
 6  },
 7  {
 8    id: 'id2',
 9    title: 'beer2',
10    price: '0.1'
11  },
12  {
13    id: 'id3',
14    title: 'beer3',
15    price: '0.1'
16  }
17];
18var list = {};
19function getProduct(id) {
20  for(var i=0; i<products.length; i++) {
21    if(products[i].id == id) {
22      return(products[i]);
23    }
24  }
25  return("not found");
26}
27function addProduct(id) {
28  if (!list[id]) {
29    list[id] = 1;
30  } else {
31    list[id]++;
32  }
33  // update html
34  var total = 0;
35  var html = "";
36  html += "<ul class='list-group'>";
37  for (var property in list) {
38    if (list.hasOwnProperty(property)) {
39      html += "<li class='list-group-item'>";
40      html += property + " x" + list[property];
41      html += "<div class='float-right'>";
42      html += (getProduct(property).price * list[property]).toFixed(4) + " eth";
43      html += "</div>";
44      html += "</li>";
45      total = (+(total) + +(getProduct(property).price * list[property])).toFixed(4);
46    }
47  }
48  html += "</ul>";
49  html += "<br>";
50  html += "<div class='float-right'>";
51  html += "<b>Total: " + total + "</b>";
52  html += "</div>";
53  html += "<br>";
54  document.getElementById("list").innerHTML = html;
55}
56
57function purchase() {
58  var total = 0;
59  for (var property in list) {
60    if (list.hasOwnProperty(property)) {
61      total = (+(total) + +(getProduct(property).price * list[property])).toFixed(4);
62    }
63  }
64  var answ = confirm("total to pay: " + total + " eth");
65  if (!answ) {
66    return;
67  }
68  axios.post('/api/purchase', {
69    list: list
70  })
71  .then(function (response) {
72    console.log(response);
73  })
74  .catch(function (error) {
75    console.log(error);
76  });
77}