echoing php data - php

Question

in the following code , I have echoed $strXML in php file,which shows the whole $strXML but I want to show just the 'name' element values in javascript. Can anybody help me?
PHP :
$strXML = '<? xml version="1.0" ?>'."\n";
$id = $_GET['id'];
$name = $_GET['name'];
$strXML .= '<data>'."\n";
$strXML .= '<id>'.$id.'</id>'."\n";
$strXML .= '<name>'.$name.'</name>'."\n";
$strXML .= '</data>'."\n";
echo $strXML;
javascript:
var xhr = createRequest();
function getData() {
if(xhr) {
var id = document.getElementById("id").value;
var name = document.getElementById("name").value;
var url = "search.php?id=" + id + "&name=" + name;
xhr.open("GET", url, true);
xhr.onreadystatechange = show;
xhr.send(null);
}
}
function show()
{
if ((xhr.readyState == 4) &&(xhr.status == 200))
{
var strXML = xhr.responseText;
alert(strXML);
}
}

Answer 1

The responseText property is a string (a DOMString in the specification but that is just a String in JavaScript) so you can't call getElementsByTagName on it; you want to look at xhr.responseXML.
Also, getElementsByTagName searches beneath the element it is called on:
The subtree underneath the specified element is searched, excluding the element itself.
So you'll have to access the contents directly rather than inside a loop:
var result = xhr.responseXML;
var id = result.getElementsByTagName('id' ).childNodes[0].nodeValue;
var name = result.getElementsByTagName('name').childNodes[0].nodeValue;
If you want to return multiple <data> elements (and hence, use your for loop) then you'll have to wrap the return value from your PHP in one more element:
<results>
<data>
<id>$id</id>
<name>$name</name>
</data>
<!-- etc. -->
</results>

Answer 2

Not to criticize your current decision, but I've found that it's much easier to use a combination of PHP and JavaScript if you use JSON for transferring the data back and forth. PHP has excellent methods to create JSON, and JavaScript... well, it is JavaScript. I think this generally makes development a whole lot easier:
<?php
$data = array(
'data' => array(
'id' => $_GET['id'],
'name' => $_GET['name']
)
);
echo json_encode( $data );
And on the JS side:
var xhr = createRequest();
function getData() {
if(xhr) {
var id = document.getElementById("id").value;
var name = document.getElementById("name").value;
var url = "search.php?id=" + id + "&name=" + name;
xhr.open("GET", url, true);
xhr.onreadystatechange = show();
xhr.send(null);
}
}
function show()
{
if ((xhr.readyState == 4) &&(xhr.status == 200))
{
var response = eval('(' + xhr.responseText + ')');
alert( response.data.id );
}
}
Of course, if you're already using the XML elsewhere (e.g. in a webservice, or using XSLT to show the page), XML would make more sense. Just my $0,02 though.