PHP XML how to output nice format

Here are the codes:

$doc = new DomDocument('1.0');
// create root node
$root = $doc->createElement('root');
$root = $doc->appendChild($root);
$signed_values = array('a' => 'eee', 'b' => 'sd', 'c' => 'df');
// process one row at a time
foreach ($signed_values as $key => $val) {
    // add node for each row
    $occ = $doc->createElement('error');
    $occ = $root->appendChild($occ);
    // add a child node for each field
    foreach ($signed_values as $fieldname => $fieldvalue) {
        $child = $doc->createElement($fieldname);
        $child = $occ->appendChild($child);
        $value = $doc->createTextNode($fieldvalue);
        $value = $child->appendChild($value);
    }
}
// get completed xml document
$xml_string = $doc->saveXML() ;
echo $xml_string;

If I print it in the browser I don’t get nice XML structure like

<xml> n tab <child> etc.

I just get

<xml><child>ee</child></xml>

And I want to be utf-8 How is this all possible to do?

Answer

You can try to do this:

...
// get completed xml document
$doc->preserveWhiteSpace = false;
$doc->formatOutput = true;
$xml_string = $doc->saveXML();
echo $xml_string;

You can make set these parameter right after you’ve created the DOMDocument as well:

$doc = new DomDocument('1.0');
$doc->preserveWhiteSpace = false;
$doc->formatOutput = true;

That’s probably more concise. Output in both cases is (Demo):

<?xml version="1.0"?>
<root>
  <error>
    <a>eee</a>
    <b>sd</b>
    <c>df</c>
  </error>
  <error>
    <a>eee</a>
    <b>sd</b>
    <c>df</c>
  </error>
  <error>
    <a>eee</a>
    <b>sd</b>
    <c>df</c>
  </error>
</root>

I’m not aware how to change the indentation character(s) with DOMDocument. You could post-process the XML with a line-by-line regular-expression based replacing (e.g. with preg_replace):

$xml_string = preg_replace('/(?:^|G)  /um', "t", $xml_string);

Alternatively, there is the tidy extension with tidy_repair_string which can pretty print XML data as well. It’s possible to specify indentation levels with it, however tidy will never output tabs.

tidy_repair_string($xml_string, ['input-xml'=> 1, 'indent' => 1, 'wrap' => 0]);