Parse XML with PHP where Value equals XX - php

Question

Want to set up a page that parse out info from a XML feed according to a give ID...
Like "Show the Course->info where Course->ID = 123"
Probably "need" to get the id from a URL Variable ... urL: ://.../courseinfo.php?id=123
This show each instance - but I want a solution that shows only info from One particual ID.
"simialr" to a sql query like "GET * where COURSE_ID=" & $urlcourseid"
$xml=simplexml_load_file("https://www.kursadmin.org/pls/kas/sf_fu.create_web_cdata_xml");
foreach($xml as $x) {
foreach($x->KURS as $y){
echo "Kursnavn: " . $y->KURS_NAVN . "<br>";
echo "KursID: " . $y->KURS_ID . "<br><br>";
echo "Formål: " . $y->FORMAL . "<br>";
//echo "Beskrivelse: <p>" . $y->INNHOLD . "</p>";
echo "<br><br> <Hr>";
}
}
Any suggestions?

Answer 1

As everyone's probably suggested, you should be using XPath to query this. What they're leaving out is that you have to mind the XML namespace before you can do that here. Here's a programmatic way to both mind the namespace, and to query for a specific record ID:
$xml = simplexml_load_file( "sf_fu.create_web_cdata_xml" );
$namespaces = $xml->getNamespaces( true ); # array([]="crystal-reports:schemas")
$namespace = array_shift( $namespaces ); # urn:crystal-reports:schemas
$xml->registerXPathNamespace("kurses", $namespace );
$results = $xml->xpath( "//kurses:KURS[kurses:KURS_ID=1463486771]" );
Note that my XPath query is prefixed with kurses: - that is the namespace prefix that I designated I wanted to use with the queries, that the XML file reflects (see the Report xmlns='' tag)
Anyhow, the result is an array of records, in our case length 1 since there's only one ID with that number. Printing it out looks like what you'd expect (redacted a few details):
print_r($results) = Array (
[0] => SimpleXMLElement Object (
[#attributes] => Array (
[SectionNumber] => 0
[teller] => 0
)
[KURSSERIE_ID] => SimpleXMLElement Object (
[#attributes] => Array (
[FieldName] => {ARRMENT_TBL.AM_ID}
)
)
[KURS_ID] => 1463486771
[KURS_NAVN] => Norsk litt øvet (A2) - Eid
[KLSTART] => 1730
Given that the record ID # is an integer, you should be able to cheaply sanitize it by doing something like:
$KURS_ID = intval( $_GET['KURS_ID'] );
...
$results = $xml->xpath( "//kurses:KURS[kurses:KURS_ID={$KURS_ID}]" );

Answer 2

the obvious way:
foreach($xml as $x) {
foreach($x->KURS as $y){
if( $y->KURS_ID == $_GET['id']){
echo "Kursnavn: " . $y->KURS_NAVN . "<br>";
echo "KursID: " . $y->KURS_ID . "<br><br>";
echo "Formål: " . $y->FORMAL . "<br>";
//echo "Beskrivelse: <p>" . $y->INNHOLD . "</p>";
echo "<br><br> <Hr>";
}
}
}