17.9 AJAX Applications

Display XML Data in an HTML Table

This example loops through each <CD> element, and displays the values of the <ARTIST> and the <TITLE> elements in an HTML table:

Example 1: AJAX Applications - Display XML Data in an HTML Table

<table id="demo"></table>

<script>
function loadXMLDoc() {
  const xhttp = new XMLHttpRequest();
  xhttp.onload = function() {
    const xmlDoc = xhttp.responseXML;
    const cd = xmlDoc.getElementsByTagName("CD");
    myFunction(cd);
  }
  xhttp.open("GET", "cd_catalog.xml");
  xhttp.send();
}

function myFunction(cd) {
  let table="<tr><th>Artist</th><th>Title</th></tr>";
  for (let i = 0; i < cd.length; i++) {
    table += "<tr><td>" +
    cd[i].getElementsByTagName("ARTIST")[0].childNodes[0].nodeValue +
    "</td><td>" +
    cd[i].getElementsByTagName("TITLE")[0].childNodes[0].nodeValue +
    "</td></tr>";
  }
  document.getElementById("demo").innerHTML = table;
}
</script>

For more information about using JavaScript and the XML DOM, go to DOM Intro.

Display the First CD in an HTML div Element

This example uses a function to display the first CD element in an HTML element with id="showCD":

Example 2: AJAX Applications - Display the First CD in an HTML div Element

const xhttp = new XMLHttpRequest();
xhttp.onload = function() {
  const xmlDoc = xhttp.responseXML;
  const cd = xmlDoc.getElementsByTagName("CD");
  myFunction(cd, 0);
}
xhttp.open("GET", "cd_catalog.xml");
xhttp.send();

function myFunction(cd, i) {
  document.getElementById("showCD").innerHTML =
  "Artist: " +
  cd[i].getElementsByTagName("ARTIST")[0].childNodes[0].nodeValue +
  "<br>Title: " +
  cd[i].getElementsByTagName("TITLE")[0].childNodes[0].nodeValue +
  "<br>Year: " +
  cd[i].getElementsByTagName("YEAR")[0].childNodes[0].nodeValue;
}

Navigate Between the CDs

To navigate between the CDs in the example above, create a next() and previous() function:

Example 3: AJAX Applications - Navigate Between the CDs

function next() {
  // display the next CD, unless you are on the last CD
  if (i < len-1) {
    i++;
    displayCD(i);
  }
}

function previous() {
  // display the previous CD, unless you are on the first CD
  if (i > 0) {
    i--;
    displayCD(i);
  }
}

Show Album Information When Clicking On a CD

The last example shows how you can show album information when the user clicks on a CD:

Example 4: AJAX Applications - Show CD Album Information

function displayCD(i) {
  document.getElementById("showCD").innerHTML =
  "Artist: " +
  cd[i].getElementsByTagName("ARTIST")[0].childNodes[0].nodeValue +
  "<br>Title: " +
  cd[i].getElementsByTagName("TITLE")[0].childNodes[0].nodeValue +
  "<br>Year: " +
  cd[i].getElementsByTagName("YEAR")[0].childNodes[0].nodeValue;
}