How to extract a node attribute from XML using PHP's DOM Parser

Question 1

I've never really used the DOM parser before and now I have a question.

How would I go about extracting the URL from this markup:

<files>
    <file path="http://www.thesite.com/download/eysjkss.zip" title="File Name" />
</files>

Question 2

Using simpleXML:

$xml = new SimpleXMLElement($xmlstr);
echo $xml->file['path']."n";

Output:

http://www.thesite.com/download/eysjkss.zip

Question 3

Did you try it? Try this example (Sample: adding data tags).

include 'simple_html_dom.php';

$html_string = '
<style>.myelems{color:green}</style>
<div>
    <p class="myelems">text inside 1</p>
    <p class="myelems">text inside 2</p>
    <p class="myelems">text inside 3</p>
    <p>simple text 1</p>
    <p>simple text 2</p>
</div>
';

$html = str_get_html($html_string);
foreach($html->find('div p[class="myelems"]') as $key => $p_tags) {
    $p_tags->{'data-index'} = $key;
}

echo htmlentities($html);

Output:

<style>.myelems{color:green}</style> 
<div> 
    <p class="myelems" data-index="0">text inside 1</p> 
    <p class="myelems" data-index="1">text inside 2</p> 
    <p class="myelems" data-index="2">text inside 3</p> 
    <p>simple text 1</p> 
    <p>simple text 2</p> 
</div>

Question 4

Well, at a minimum, you have to download the portion of the archive up to and including the compressed data of the file you want to extract. That suggests the following solution: open a URLConnection to the archive, get its input stream, wrap it in a ZipInputStream, and repeatedly call getNextEntry() and closeEntry() to iterate through all the entries in the file until you reach the one you want. Then you can read its data using ZipInputStream.read(...).

The Java code would look something like this:

URL url = new URL("http://example.com/path/to/archive");
ZipInputStream zin = new ZipInputStream(url.getInputStream());
ZipEntry ze = zin.getNextEntry();
while (!ze.getName().equals(pathToFile)) {
    zin.closeEntry(); // not sure whether this is necessary
    ze = zin.getNextEntry();
}
byte[] bytes = new byte[ze.getSize()];
zin.read(bytes);

This is, of course, untested.

Question 5

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>';

Question 6

You need to import any node to append it to another document:

$departmentArray->item($i)->appendChild( $doc->importNode( $employee, true ) );

How to extract a node attribute from XML using PHP's DOM Parser

Answers

php,xml,dom