This chapter demonstrates some HTML applications using XML, HTTP, DOM, and JavaScript.
The XML Document Used
In this chapter we will use the XML file called "cd_catalog.xml" .
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
<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> </body> </html>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
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
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
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;
}