Question

I am using SimpleXML to build a document, and wondering whether it is possible to insert comment tag to the document like this:

<root>
  <!-- some comment -->
  <value>
</root>

EDIT:

The comment is somewhere in the middle of the document.

<root>
  <tag1 />
  <!-- some comment -->
  <value />
</root>

Answer 1

Unfortunately, SimpleXML doesn’t handle comments. As it’s been mentionned, DOM does handle comments but it’s a kind of a bother to use for simple stuff, compared to SimpleXML.

My recommendation: try SimpleDOM. It’s an extension to SimpleXML, so everything works the same and it has a bunch of useful methods to deal with DOM stuff.

For instance, insertComment($content, $mode) can append to or insert comments before or after a given node. For example:

include 'SimpleDOM.php';

$root = simpledom_load_string('<root><value/></root>');

$root->value->insertComment(' mode: append ', 'append');
$root->value->insertComment(' mode: before ', 'before');
$root->value->insertComment(' mode: after ', 'after');

echo $root->asPrettyXML();

…will echo

<?xml version="1.0"?>
<root>
  <!-- mode: before -->
  <value>
    <!-- mode: append -->
  </value>
  <!-- mode: after -->
</root>