21. Processing XML Documents

Consider the following XML file [data.xml]:

<?xml version="1.0" encoding="UTF-8"?>

<tribu>
    <teacher>
        <person gender="M">
            <last_name>dupont</last_name>
            <first_name>Jean</first_name>
            <age>28</age>
            This is a comment
        </person>
        <section>27</section>
    </teacher>
    <student>
        <person gender="F">
            <last name>martin</last name>
            <first_name>Charline</first_name>
            <age>22</age>
        </person>
        <education>IAIE degree</education>
    </student>
</group>

We analyze this document with the following script:

<?php

// XML file to process
$FILE_NAME = "data.xml";
// processing
$xml = simplexml_load_file($FILE_NAME);
print_r($xml);
print_r($xml->teacher->person['gender']);
$name = $xml->teacher->person->name;
print "name=$name\n";
$gender = $xml->teacher->person['gender'];
print "gender=$gender\n";
$education = $xml->student->education;
print "education=$education\n";
print "isset=".isset($xml->teacher->person->name)."\n";
print "isset=".isset($xml->teacher->person->xx)."\n";

Here we use a PHP module called [simpleXML] that allows us to process XML documents.

• line 6: loading the XML file;
• line 7: displaying the XML document;
• line 8: displaying the value of the 'sex' attribute of a teacher: <teacher><person sex='…'>;
• line 9: displaying the value of the first tag <teacher><person><name>;

Note that the root tag <tribe> does not appear in the code. It could be anything;

Console output

SimpleXMLElement Object
(
    [teacher] => SimpleXMLElement Object
        (
            [person] => SimpleXMLElement Object
                (
                    [@attributes] => Array
                        (
                            [gender] => M
                        )

                    [last_name] => Dupont
                    [first_name] => Jean
                    [age] => 28
                )

            [section] => 27
        )

    [student] => SimpleXMLElement Object
        (
            [person] => SimpleXMLElement Object
                (
                    [@attributes] => Array
                        (
                            [gender] => F
                        )

                    [last_name] => martin
                    [first_name] => charline
                    [age] => 22
                )

            [education] => IAIE degree
        )

)
SimpleXMLElement Object
(
    [0] => M
)
name=dupont
gender=M
education=IAIE design
isset=1
isset=

• lines 1-37: the XML document in the form of a [simpleXML] object.

The previous script does not show us all the possibilities of the [simpleXML] module, but it is sufficient for us to write a new version of the application exercise.