Saving HTML form data to XML file

Question

I'm trying to save the results of an HTML form to an XML file for later processing. The form has Unfortunately, it looks like I can only save one answer at a time, but I'd like to write all the answers in the XML file. Here is what I tried:

<?php
if(isset($_POST['submit']))
{
    $mileage = $_POST['form'];
    $file = fopen("data.xml","r+");
    fwrite($file,$mileage);
    fclose($file); 
    print_r(error_get_last());
}
?>

<form action= "" method="post" name="form">
<input type="hidden" value = "<?xml version='1.0' encoding='UTF-8'?>"/>
<input type="hidden" value="<miles>"/>
<span class="XMLsimpleType" onclick="selectelm(this, event);" ondblclick="selectelm(this, event);">
<label>Car: </label>
<input type="text" class="car" name="car" value="" onfocus="focusGained(this)" onchange="textChanged(this)" /></span>
<br/></span>
<br>
<span class="XMLsimpleType" onclick="selectelm(this, event);" ondblclick="selectelm(this, event);">
<span class="bike">
<label>Bike: </label>
<input type="text" class="bike" name="bike" value="" onfocus="focusGained(this)" onchange="textChanged(this)" /></span>
<br/></span>
<br>
<input type="hidden" value="</miles>"/>
<input type="submit" name="submit" value="submit"><br>
</form>

The form should create a properly formatted simple XML file that looks like this:

<?xml version='1.0' encoding='UTF-8'?>
<miles>
<car>123</car>
<bike>245</bike>
</miles>

I've spent the past four hours looking at this, and I know I can make it simpler, but first I'd like to just get it working. I can write a single form entry, but not the whole form with the XML information. What have I done wrong?

You cannot process the form the way you are trying to do it. For one, your $_POST array only contains the input elements with a name attribute (i.e. car, bike and submit in your form). The answer would be to turn your $_POST array into a valid XML structure, using SimpleXMLElement, see the link [link]https://stackoverflow.com/questions/1397036/how-to-convert-array-to-simplexml — lovelace, Oct 07 '17 at 20:46
I tried to just combine all input elements into one $_Post, using periods, commas, and just spaces, and none of that worked. I'll look into the SimpleXMLElement, unless there is an easier way to combine things. — Harold Scott, Oct 07 '17 at 22:15

score 2 · Accepted Answer · answered Oct 07 '17 at 22:27

This should work (I have split the form and processing into two seperate files):

yourform.php (simplified):

<form action='showXML.php' method='POST'>
car <input type='text' name='car'>
<br />
bike <input type='text' name='bike'>
<input type='submit' name='submit' value='submit'>
</form>

showXML.php:

<?php
if(isset($_POST['submit']))
{
$xml = new SimpleXMLElement("<?xml version=\"1.0\" encoding=\"utf-8\" ?><miles></miles>");

    $xml->addChild('car', $_POST['car']);
    $xml->addChild('bike', $_POST['bike']);

    $asXML = $xml->asXML();
    $file = fopen("data.xml","w+");
    fwrite($file,$asXML);
    fclose($file); 
    print_r(error_get_last());

    if(file_exists('./data.xml'))
    {
        $myXML = file_get_contents('./data.xml');
        $xml = new SimpleXMLElement($myXML);
        $xmlpretty = $xml->asXML();

        // pretty print the XML in browser
        header('content-type: text/xml');
        echo $xmlpretty;
    }

}
?>

That worked. I was getting close with SimpleXMLElement, but I couldn't figure out how to use $_Post with the array. I was about to try just writing $asXML to a file, which is what you appeared to do. Excellent, job, thanks. — Harold Scott, Oct 07 '17 at 22:35

Saving HTML form data to XML file

1 Answers1