XML获取属性

Question

I saw lots of tutorials here in overflow, but I could not understand what I am missing.. So I need some help..

I have an XML which it is online and I am trying to parse it like this:

<products>
    <product>
    <id>13389</id>
    <name><![CDATA[ product name ]]></name>
    <category id="14"><![CDATA[ Shoes > test1 ]]></category>
    <price>41.30</price>
</products>

As far, I am reading the XML and parsing it like this:

$reader = new XMLReader();
$reader->open($product_xml_link);
while($reader->read()) {
if($reader->nodeType == XMLReader::ELEMENT && $reader->name == 'product' ) {
    $product = new SimpleXMLElement($reader->readOuterXml());
    $pid = $product->id;
    $name = $product->name;
    $name = strtolower($name);
    $link = $product->link;
    $price = $product->Price;
    ...
    ...
}
} //end while loop

As you can see, there is an id in category tag.. This is the one I would like to grab and procceed to my code..

I did something like this:

echo "prodcut= " . (string)$product->category->getAttribute('id');

The error I am getting is: Call to undefined method SimpleXMLElement::getAttribute()

I need this id in order to test it before insert it in DB.. So,

if($id = 600) {
//insert DB
}

Answer 1

Here are several things. First $product = new SimpleXMLElement($reader->readOuterXml()); means that you're reading all that as an separate XML document and parse again. Here is expand(), that will return directly an DOM node and DOM nodes can be imported into SimpleXML.

For attributes use array syntax..

$reader = new XMLReader();
$reader->open($product_xml_link);

// an document to expand to
$document = new DOMDocument();

// find the first product node
while ($reader->read() && $reader->localName !== 'product') {
  continue;
}

while ($reader->localName === 'product') {
  $product = simplexml_import_dom($reader->expand($document));
  $data = [
    'id' => (string)$product->id,
    'name' => (string)$product->name,
    'category_id' => (string)$product->category['id'],
    // ...
  ];
  var_dump($data);
  // move to the next product sibling
  $reader->next('product');
}
$reader->close();

Output:

array(3) {
  ["id"]=>
  string(5) "13389"
  ["name"]=>
  string(14) " product name "
  ["category_id"]=>
  string(2) "14"
}

Of course you can use the DOM directly and fetch the detail data using Xpath expressions:

$reader = new XMLReader();
$reader->open($product_xml_link);

// prepare a document to expand to
$document = new DOMDocument();
// and an xpath instance to use
$xpath = new DOMXpath($document);

// find the first product node
while ($reader->read() && $reader->localName !== 'product') {
  continue;
}

while ($reader->localName === 'product') {
  $product = $reader->expand($document);
  $data = [
    'id' => $xpath->evaluate('string(id)', $product),
    'name' => $xpath->evaluate('string(name)', $product),
    'category_id' => $xpath->evaluate('string(category/@id)', $product),
    // ...
  ];
  var_dump($data);
  // move to the next product sibling
  $reader->next('product');
}
$reader->close();