使用unset（）删除XML中的节点; PHP /使用simplexml_load_file

Question

I'm trying to use unset() to delete a node in an XML using PHP and can't figure out what is going on here. It doesn't seem to work correctly and I've seen a lot of other questions of similar nature on here but they don't seem to address this issue directly. Here's what my XML looks like:

<?xml version="1.0" encoding="UTF-8"?>
<data>
    <user>
        <name>Test Name 1</name>
        <email>[e-mail]</email>
        <spouse/>
    </user>
    <user>
        <name>Test Name 2</name>
        <email>[e-mail]</email>
        <spouse>Test Name 3</spouse>
    </user>
</data>    

My loop that I'm using is like this:

url = 'data/users.xml';
$xml = simplexml_load_file($url);

foreach($xml->user as $theUser){
    if($theUser->email[0]=="[e-mail]"){
        echo "test";
        unset($theUser);
    }
}

When the e-mail matches "[e-mail]" I want to be able to delete that whole user node. It seems that this should work but I can't figure out why it wouldn't? Any help would be greatly appreciated. Thank you!

Answer 1

SimpleXML is fine, no need to switch to DOM, unset() is working fine, if you do it right:

unset($theUser[0]);

see it working: https://eval.in/228773

However there will be a problem with your foreach() if you delete a node mid-loop.

I suggest to use xpath() instead of a loop, IMO elegant and the code is much simpler.

$users = $xml->xpath("/data/user[email='[e-mail]']");

will create an array of all <user> with that email-address.

unset($users[0][0]);

will delete the first user in that array.

foreach ($users as $user) unset($user[0]);

will delete the whole array.

see this in action: https://eval.in/228779