无法保存已用PHP + SimpleXML更新的XML文件

Question

I'm trying to edit the values of a customer in an XML file using PHP and SimpleXML. I can seem to be able to write new data to the file, and edit the values of a customer but I cannot get those changes to save to the file.

I have tried to chmod 777 -R where this project is located on my server but nothing changes, and I can also write new data to the same customers.xml file in another method, so I'm ruling out an issue with permissions. Additionally, I have tried saving the file with file_put_contents() with no good results.

The intended goal of this function is to do an XPath expression to get the customer that is to be modified, update the values of that customer, then save the edited changes of that customer to file, as well the rest of the XML document - which should be unchanged, since only one customer can be updated at a time.

$customersXml = simplexml_load_file('customers.xml', null, true) or die('Error: Cannot load XML from file customers.xml"');
$customerToEdit = $customersXml->xpath('//customer[position()="'.$customerIndexOfMatch.'"]/customerInfo');

if (isset($_POST['updateCustomer'])){
    // updating the data seems to work fine
    $customerToEdit[0]->firstName = $_POST['edit-fname'];
    $customerToEdit[0]->middleName = $_POST['edit-mname'];
    $customerToEdit[0]->lastName = $_POST['edit-lname'];
    $customerToEdit[0]->address = $_POST['edit-address'];
    $customerToEdit[0]->telephone[0] = $_POST['edit-ph1'];
    $customerToEdit[0]->telephone[1] = $_POST['edit-ph2'];
    $customerToEdit[0]->telephone[2] = $_POST['edit-ph3'];

    // but when it comes to saving the updated data, i'm baffled (this method of saving has worked in another function)
    // have also tried file_put_contents('customers.xml', $customersXml->asXML()) which doesn't work here
    $customersXml->asXML('customers.xml');

    echo '<pre>';
    var_dump($customerToEdit);                          
}

The output of var_dump(), after changing customer Bart's name to Homer:

array(1) {
  [0]=>
  object(stdClass)#3 (5) {
    ["firstName"]=>
    string(4) "Homer"
    ["middleName"]=>
    string(0) ""
    ["lastName"]=>
    string(7) "Simpson"
    ["address"]=>
    string(28) " ... "
    ["telephone"]=>
    array(3) {
      [0]=>
      string(10) "111222333"
      [1]=>
      string(10) "444555666"
      [2]=>
      string(10) "777888999"
    }
  }
}

Also, here is the structure of my XML document:

<customers>
    <customer number="" meterNumber=""> 
        <customerInfo>
            <title></title> 
            <firstName></firstName>
            <middleName></middleName>
            <lastName></lastName>
            <address></address>
            <telephone></telephone>
            <telephone></telephone>
            <telephone></telephone>
        </customerInfo>

        <prevMeterReadings>
            <reading />
        <prevMeterReadings>
    </customer>
</customers>

Any help would be greatly appreciated! Would love for the edited data to save correctly to file!

Answer 1

Ok so I've figured out what the issue was.

The solution was to change these lines from:

$customerToEdit[0]->firstName = $_POST['edit-fname'];
...

to

$customersXml->customer[$customerIndexOfMatch]->customerInfo->firstName = $_POST['edit-fname'];
...