XML parse by id help

Question

XML newbie, have no idea what I'm doing. I need a well explained, simple way to do this please.

From a previous page I use query strings to get an id example: test.php?id=AT

I need to display all the employee names within the department that they select. Below is a snipit of my XML document.

<SOT>
    <DEPARTMENT name="Aviation Technology" id="AT">
        <EMPLOYEE type="Faculty">
            <LOGIN>bdbowen</LOGIN>
            <PASSWORD>bdbowen</PASSWORD>
            <NAME>John J. Doe</NAME>
            <IMAGE>images/faculty/bdbown.jpg</IMAGE>
            <OFFICE>Knoy</OFFICE>
            <PHONE>765.494.2884</PHONE>
            <EMAIL>dsgriggs@purdue.edu</EMAIL>
        </EMPLOYEE>
        <EMPLOYEE type="Faculty">
            <LOGIN>bdbowen</LOGIN>
            <PASSWORD>bdbowen</PASSWORD>
            <NAME>Jill J. Doe</NAME>
            <IMAGE>images/faculty/bdbown.jpg</IMAGE>
            <OFFICE>Knoy</OFFICE>
            <PHONE>765.494.2884</PHONE>
            <EMAIL>dsgriggs@purdue.edu</EMAIL>
        </EMPLOYEE>
    </DEPARTMENT>
    <DEPARTMENT name="Mechanical Engineering Technology" id="MET">
        <EMPLOYEE type="Faculty">
            <LOGIN>bdbowen</LOGIN>
            <PASSWORD>bdbowen</PASSWORD>
            <NAME>John J. Doe</NAME>
            <IMAGE>images/faculty/bdbown.jpg</IMAGE>
            <OFFICE>Knoy</OFFICE>
            <PHONE>765.494.2884</PHONE>
            <EMAIL>dsgriggs@purdue.edu</EMAIL>
        </EMPLOYEE>
    </DEPARTMENT>
</SOT>

For instance, if they select the link that uses a GET to pull in the AT id, I want to display the following on the page:

John J. Doe
Jill J. Doe

Again, I have no idea what I'm doing here so anyhelp would be greatly appreciated.

---

I tried the following code but it only displays the first name for every department. Any idea how to ammend it to show all the names within a department?

<script type="text/javascript">
if (window.XMLHttpRequest)
  {// code for IE7+, Firefox, Chrome, Opera, Safari
  xmlhttp=new XMLHttpRequest();
  }
else
  {// code for IE6, IE5
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
xmlhttp.open("GET","faculty1.xml",false);
xmlhttp.send();
xmlDoc=xmlhttp.responseXML; 

document.write("<table border='1'>");
var x=xmlDoc.getElementsByTagName("DEPARTMENT");
for (i=0;i<x.length;i++)
  { 
  document.write("<tr><td>");
  document.write(x[i].getElementsByTagName("NAME")[0].childNodes[0].nodeValue);
  document.write("</td></tr>");
  }
document.write("</table>");
</script>

Answer 1

You can use an xpath expression:

See: https://github.com/homer6/altumo/blob/master/source/php/Xml/XmlElement.md

$xml = <<<XML
<SOT>
    <DEPARTMENT name="Aviation Technology" id="AT">
        <EMPLOYEE type="Faculty">
            <LOGIN>bdbowen</LOGIN>
            <PASSWORD>bdbowen</PASSWORD>
            <NAME>John J. Doe</NAME>
            <IMAGE>images/faculty/bdbown.jpg</IMAGE>
            <OFFICE>Knoy</OFFICE>
            <PHONE>765.494.2884</PHONE>
            <EMAIL>dsgriggs@purdue.edu</EMAIL>
        </EMPLOYEE>
        <EMPLOYEE type="Faculty">
            <LOGIN>bdbowen</LOGIN>
            <PASSWORD>bdbowen</PASSWORD>
            <NAME>Jill J. Doe</NAME>
            <IMAGE>images/faculty/bdbown.jpg</IMAGE>
            <OFFICE>Knoy</OFFICE>
            <PHONE>765.494.2884</PHONE>
            <EMAIL>dsgriggs@purdue.edu</EMAIL>
        </EMPLOYEE>
    </DEPARTMENT>
    <DEPARTMENT name="Mechanical Engineering Technology" id="MET">
        <EMPLOYEE type="Faculty">
            <LOGIN>bdbowen</LOGIN>
            <PASSWORD>bdbowen</PASSWORD>
            <NAME>John J. Doe</NAME>
            <IMAGE>images/faculty/bdbown.jpg</IMAGE>
            <OFFICE>Knoy</OFFICE>
            <PHONE>765.494.2884</PHONE>
            <EMAIL>dsgriggs@purdue.edu</EMAIL>
        </EMPLOYEE>
    </DEPARTMENT>
</SOT>
XML;

$xml_element = new \Altumo\Xml\XmlElement($xml);
$results = $xml_element->queryWithXpath( 'DEPARTMENT[@id="AT"]/EMPLOYEE/NAME' );
var_dump( $results );


array(2) {
  [0]=>
  string(11) "John J. Doe"
  [1]=>
  string(11) "Jill J. Doe"
}

Answer 2

Edit: After some some hints from Gordon here's my edited code:

$xmlObject = smplexml_load_file("staff.xml");
$id = $_GET["id"];
$employees = null;

foreach($xmlObject as $key => $value){
    $attributes = $xmlObject[0]->DEPARTMENT->attributes();
    if($attributes["id"] == $id){
        $employees = $xmlObject[0]->DEPARTMENT->EMPLOYEE;
        break;
    }
}

foreach($employees as $key => $value){
    print $value->NAME . "\n";
}

Basically you will get a list of employes in the $employees variable which you can iterate through and retrieve the name as you stated you wanted.