Updating the XML file using PHP script - php

Question

I'm making an interface-website to update a concert-list on a band-website.
The list is stored as an XML file an has this structure :
I already wrote a script that enables me to add a new gig to the list, this was relatively easy...
Now I want to write a script that enables me to edit a certain gig in the list.
Every Gig is Unique because of the first attribute : "id" .
I want to use this reference to edit the other attributes in that Node.
My PHP is very poor, so I hope someone could put me on the good foot here...
My PHP script :

Answer 1

Well i dunno what your XML structure looks like but:
<gig id="someid">
<venue></venue>
<day></day>
<month></month>
<year></year>
</gig>
$xml = new SimpleXmlElement('gig.xml',null, true);
$gig = $xml->xpath('//gig[#id="'.$_POST['id'].'"]');
$gig->venue = $_POST['venue'];
$gig->month = $_POST['month'];
// etc..
$xml->asXml('gig.xml)'; // save back to file
now if instead all these data points are attributes you can use $gig->attributes()->venue to access it.
There is no need for the loop really unless you are doing multiple updates with one post - you can get at any specific record via an XPAth query. SimpleXML is also a lot lighter and a lot easier to use for this type of thing than DOMDOcument - especially as you arent using the feature of DOMDocument.

Answer 2

You'll want to load the xml file in a domdocument with
<?
$xml = new DOMDocument();
$xml->load("xmlfile.xml");
//find the tags that you want to update
$tags = $xml->getElementsByTagName("GIG");
//find the tag with the id you want to update
foreach ($tags as $tag) {
if($tag->getAttribute("id") == $id) { //found the tag, now update the attribute
$tag->setAttribute("[attributeName]", "[attributeValue]");
}
}
//save the xml
$xml->save();
?>
code is untested, but it's a general idea