Write a foreach loop for array of SimpleXMLElement

问题:

I am using the XPath in PHP 5 to parse a XML document. The problem I have is writing a foreach to correctly display the following array:

XML document sample

value 1 value 2

           $xmlfile = 'link_to_file.xml';                       
            $xmlRaw = file_get_contents($xmlfile);      
            $xml = new SimpleXMLElement($xmlRaw);
            $install_files = $xml->xpath('//files');
            foreach($install_files as $row)
            {
              echo $row['file'];
            }

//var_dump for $row gives the following

               array(1) {
                  [0]=>
                  object(SimpleXMLElement)#21 (2) {
                    ["file"]=>
                    string(12) "value 1"
                    ["folder"]=>
                    string(8) "value 2"
                  }
                }

Ideally I would like to get the value by using $row['file'] or $row['folder']. Thanks for any help.

回答1:

The items in your array are SimpleXMLElement objects. You can access their properties with the $object->property syntax. So try this:

foreach ($array as $row) {
    echo $row->folder . $row->file;
}

回答2:

If I understand your example correctly,

foreach ($array as $row)
{
    // do something with $row['file'] or $row['folder']
}

回答3:

If you want to process only one element you don't necessarily need a loop, but it doesn't hurt either.
According to your output file and folder are child-elements of the element returned for your xpath query. You can access them via $parentElement->childElement. If they were attributes you'd use $element['attributeName']

$foo = new SimpleXMLElement(getData());

foreach( $foo->xpath('row[@id="r2"]') as $row ) {
  echo $row->file, " | ", $row->folder, "\n";
}
echo "-----\n";

// same thing if you have more than one element in your result set
foreach( $foo->xpath('row[@id="r2" or @id="r3"]') as $row ) {
  echo $row->file, " | ", $row->folder, "\n";
}

function getData() {
  return '<foo>
    <row id="r1">
      <file>value 1.1</file>
      <folder>value 1.2</folder>
    </row>
    <row id="r2">
      <file>value 2.1</file>
      <folder>value 2.2</folder>
    </row>
    <row id="r3">
      <file>value 3.1</file>
      <folder>value 3.2</folder>
    </row>
  </foo>';
}

prints

value 2.1 | value 2.2
-----
value 2.1 | value 2.2
value 3.1 | value 3.2