Domdocument : Select Element By Unique Id

[mayid]

Hi. I´m learning about xml to feed a photo gallery. I´m able to read the file by simple_xml. But now i´m trying to set new values by users interface.I think the best way to achieve taht is using PHP DomDocument . But how? Documentation is really hard to find and to understand.Here my xml structure: <galeria><photo id='a2.jpg'><titulo>Heres the title</titulo><descripcion>This picture´s about dada</descripcion></photo><photo id='Henry-Rousseau.jpg'><titulo></titulo><descripcion></descripcion></photo></galeria>And i should be able to select the photo by id, and modify the title of it.I´ll appreciate your comments. Regards. G.

[Ingolme]

You have to loop through every <photo> element, and check the id attribute of each one.

foreach($xmlDoc->getElementsByTagName('photo') as $element) {  if($element->getAttribute('id') == 'a2.jpg') {	// Do something here  }}

[mayid]

Thanks! I´m trying not to use this method, because i can´t imagine how to "Do something here" for childs nodes.Now i can access child node i wanted by xpath (using id, and so). This way:$xpath = new DOMXPath($xml);$set = $xpath->query("//*[@id = '".$foto."']");$result = $set->item(0)->getElementsByTagName($seccion)->item(0)->nodeValueAnd i´m getting results. But how to define a new content to the node?

[boen_robot]

Instead of storing the result in $result, assign a new value at that point, like:

$set->item(0)->getElementsByTagName($seccion)->item(0)->nodeValue = "New value";

Note that instead of using XPath or checking each node, you could also use getElementById(), but only after you explicitly specify the "id" attribute as being the ID attribute, like:

$xml = new DOMDocument;$xml->load('galeria.xml');$xml->setIdAttribute('id', true);$a2 = $xml->getElementById('a2.jpg');

[mayid]

Instead of storing the result ...

This seems to be key.And thanks for the id setting tip.I´m working into a funtion, that returns the xml perfectly, with the new contents. But they are not actually being saved.$xml->formatOutput = true;// $xml->saveXML();return $xml->saveXML();

[boen_robot]

saveXML() only gives you the resulting XML. Nothing more, nothing less.To actually save the file you need to use save() instead of saveXML(), or write the results from saveXML() with file_put_contents(). There is a slight performance difference between these two options, but which one you chose should depend on your full scenario. In short - if you want to only save the file, save() is better. If you want to display AND save the file, saveXML() + file_put_contents() is better than having calls to both save() and saveXML().

[mayid]

WORKING! save() did the job. Thanks a lot!You know DOM is not that simple to be studied on PHP manual. So forums are a great to learn.