How do I remove a specific node using its attribute value in PHP XML Dom?

Question

My question is best phrase as: http://stackoverflow.com/questions/262351/remove-a-child-with-a-specific-attribute-in-simplexml-for-php

except I'm not using simpleXML.

I'm new to XML for PHP so I may not be doing the best way

I have a xml created using the $dom->save($xml) for each individual user. (not placing all in one xml due to undisclosed reasons)

It gives me that xml declaration <?xml version="1.0"?> (no idea how to make it to others, but that's not the point, hopefully)

<?xml version="1.0"?>
<details>
 <person>name</person>
 <data1>some data</data1>
 <data2>some data</data2>
 <data3>some data</data3>
 <category id="0">
  <categoryName>Cat 1</categoryName>
  <categorydata1>some data</categorydata1>
 </category>
 <category id="1">
  <categoryName>Cat 2</categoryName>
  <categorydata1>some data</categorydata1>
  <categorydata2>some data</categorydata2>
  <categorydata3>some data</categorydata3>
  <categorydata4>some data</categorydata4>
 </category>
</details>

And I want to remove a category that has a specific attribute named id with the DOM class in php when i run a function activated from using a remove button.

the following is the debug of the function im trying to get to work. Can i know what I'm doing wrong?

function CatRemove($myXML){
     $xmlDoc = new DOMDocument();
     $xmlDoc->load( $myXML );
     $categoryArray = array();

     $main = $xmlDoc->getElementsByTagName( "details" )->item(0);

     $mainElement = $xmlDoc->getElementsByTagName( "details" );
     foreach($mainElement as $details){
      $currentCategory = $details->getElementsByTagName( "category" );
      foreach($currentCategory as $category){
       $categoryID = $category->getAttribute('id');
       array_push($categoryArray, $categoryID);
       if($categoryID == $_POST['categorytoremoveValue']) {
        return $categoryArray;
       }
      }
     }


     $xmlDoc->save( $myXML );
    }

Well the above prints me an array of [0]->0 all the time when i slot the return outside the if. is there a better way? I've tried using getElementbyId as well but I've no idea how to work that.

I would prefer not to use an attribute though if that would make things easier.

Answer 1

So you want to remove the category node with a specific id?

$node = $xmlDoc->getElementById("12345");
if ($node) {
    $node->parentNode->removeChild($node);
}

You could also use XPath to get the node, for example:

$xpath = new DOMXpath($xmlDoc);
$nodeList = $xpath->query('//category[@id="12345"]');
if ($nodeList->length) {
    $node = $nodeList->item(0);
    $node->parentNode->removeChild($node);
}

I haven’t tested it but it should work.

Answer 2

*invalid state.

Answer 3

*invalid state

Answer 4

Tested both types. I'm afraid it's not working.

the first non-xpath method does not recognise the $node as a node that fits the parameter.

the other does not run the remove

Answer 5

Can you try with this modified version:

function CatRemove($myXML, $id){
    $doc = new DOMDocument();
    $doc->loadXML($myXML);
    $xpath = new DOMXpath($doc);
    $nodeList = $xpath->query("//category[@id='$id']");
    foreach ($nodeList as $element) {
        $element->parentNode->removeChild($element);
    }

    echo htmlentities($doc->saveXML());
}

It's working for me. Just adapt it to your needs. It's not intended to use as-is, but just a proof of concept. You also have to remove the xml declaration from the string.

Answer 6

here's my modified version that's not working still. No errors but not sure what's missing...

function CatRemove($myXML){
 $xmlDoc = new DOMDocument();
 $xmlDoc->load( $myXML );
 $IDtoRemove = $_POST['CatID'];

 //ADD REMOVE BIT HERE  
 $xmlDoc_string = $xmlDoc->saveXML(); 
 $xmlDoc->loadXML($xmlDoc_string); 
 $xpath = new DOMXpath($xmlDoc);
 $nodeList = $xpath->query("//category[@id='$IDtoRemove']");
 foreach ($nodeList as $element) {
  $element->parentNode->removeChild($element);
 }

 $xmlDoc->save( $myXML );
}

fails also if i switched

$nodeList = $xpath->query("//category[@id='$IDtoRemove']");

to

$nodeList = $xpath->query('//category[@id="'.$IDtoRemove.'"]');

Answer 7

Ok, let’s try this complete example of use:

function CatRemove($myXML, $id) {
    $xmlDoc = new DOMDocument();
    $xmlDoc->load($myXML);
    $xpath = new DOMXpath($xmlDoc);
    $nodeList = $xpath->query('//category[@id="'.(int)$id.'"]');
    if ($nodeList->length) {
     $node = $nodeList->item(0);
     $node->parentNode->removeChild($node);
    }
    $xmlDoc->save($myXML);
}

// test data
$xml = <<<XML
<?xml version="1.0"?>
<details>
 <person>name</person>
 <data1>some data</data1>
 <data2>some data</data2>
 <data3>some data</data3>
 <category id="0">
  <categoryName>Cat 1</categoryName>
  <categorydata1>some data</categorydata1>
 </category>
 <category id="1">
  <categoryName>Cat 2</categoryName>
  <categorydata1>some data</categorydata1>
  <categorydata2>some data</categorydata2>
  <categorydata3>some data</categorydata3>
  <categorydata4>some data</categorydata4>
 </category>
</details>
XML;
// write test data into file
file_put_contents('untitled.xml', $xml);
// remove category node with the id=1
CatRemove('untitled.xml', 1);
// dump file content
echo '<pre>', htmlspecialchars(file_get_contents('untitled.xml')), '</pre>';

Answer 8

Thanks for the support and answers.

thanks Gumbo and stunti for the help.

I'll love to send ya all bear hugs =D

I got it to work now :)

Answer 9

Thanks a lot to Gumbo.. I worked on that.. is it possible to edit the xml that means.. In that exmple, Cat 1 tag is there. shall i change it to Excellent? Can you please healp me?

Answer 10

the above funciton modified to remove an email from a mailing list

function CatRemove($myXML, $id) {
    $xmlDoc = new DOMDocument();
    $xmlDoc->load($myXML);
    $xpath = new DOMXpath($xmlDoc);
    $nodeList = $xpath->query('//subscriber[@email="'.$id.'"]');
    if ($nodeList->length) {
        $node = $nodeList->item(0);
        $node->parentNode->removeChild($node);
    }
    $xmlDoc->save($myXML);
}
$xml = 'list.xml';
$to = $_POST['email'];//user already submitted they email using a form 
CatRemove($xml,$to);