XML
Applications
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
<html>
<head>
<style>
table,
th, td {
border: 1px solid black;
border-collapse:collapse;
}
th,
td {
padding: 5px;
}
</style>
</head>
<body>
<table
id="demo"></table>
<script>
function
loadXMLDoc() {
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function() {
if (this.readyState == 4 &&
this.status == 200) {
myFunction(this);
}
};
xmlhttp.open("GET", "cd_catalog.xml",
true);
xmlhttp.send();
}
function
myFunction(xml) {
var i;
var xmlDoc = xml.responseXML;
var
table="<tr><th>Artist</th><th>Title</th></tr>";
var x =
xmlDoc.getElementsByTagName("CD");
for (i = 0; i <x.length; i++) {
table += "<tr><td>" +
x[i].getElementsByTagName("ARTIST")[0].childNodes[0].nodeValue
+
"</td><td>" +
x[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
displayCD(0);
function
displayCD(i) {
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function() {
if (this.readyState == 4 &&
this.status == 200) {
myFunction(this, i);
}
};
xmlhttp.open("GET",
"cd_catalog.xml", true);
xmlhttp.send();
}
function
myFunction(xml, i) {
var xmlDoc = xml.responseXML;
x =
xmlDoc.getElementsByTagName("CD");
document.getElementById("showCD").innerHTML =
"Artist: " +
x[i].getElementsByTagName("ARTIST")[0].childNodes[0].nodeValue
+
"<br>Title: " +
x[i].getElementsByTagName("TITLE")[0].childNodes[0].nodeValue
+
"<br>Year: " +
x[i].getElementsByTagName("YEAR")[0].childNodes[0].nodeValue;
}
»
Navigate
Between the CDs
To navigate
between the CDs, in the example above, add a next() and previous() function:
Example
function
next() {
// display the next CD, unless you are on the
last CD
if (i < x.length-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:
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