Combining several XML documents sequential with PHP - php

Question

I am trying to merge xml-documents from folder "files" into one DOMDocument, and create a table of contents.
The documents have the following structure:
<chapter title="This is first chapter">
<section title="This is the first section">
<paragraph title="This is the first paragraph">This is the paragraph content</paragraph>
</section>
</chapter>
The following code is used for merging the XML-files:
foreach(glob("files/*xml") as $filename) {
$count++;
if ($count == 1)
{
$first = new DOMDocument("1.0", 'UTF-8');
$first->formatOutput = true;
$first->load($filename);
$xml = new DOMDocument("1.0", 'UTF-8');
$xml->formatOutput = true;
}
else {
$second = new DOMDocument("1.0", 'UTF-8');
$second->formatOutput = true;
$second->load($filename);
$second = $second->documentElement;
foreach($second->childNodes as $node)
{
$importNode = $first->importNode($node,TRUE);
$first->documentElement->appendChild($importNode);
}
$first->saveXML();
$xml->appendChild($xml->importNode($first->documentElement,true));
}
}
print $xml->saveXML();
Everything seems to work OK, except a problem with <chapter>-elements. This is what happens when two documents (let's say two identical versions of the XML i presented in the beginning of my question) are merged:
<chapter title="This is first chapter">
<section title="This is the first section">
<paragraph title="This is the first paragraph">This is the paragraph content</paragraph>
</section>
<chapter title="This is second chapter">
<section title="This is the first section">
<paragraph title="This is the first paragraph">This is the paragraph content</paragraph>
</section>
</chapter>
</chapter>
I think the reason for this problem, is that there are no root element for the merged documents. So, is there for example a way to add a <doc> tag or something for the merged XML's?

Answer 1

Look at it from another view point. You create a new document that combines all the chapters of you book. So create a book element and import the chapters into it.
// create a new document
$dom = new DOMDocument();
// and add the root element
$dom->appendChild($dom->createElement('book'));
// for each document/xml to add
foreach ($chapters as $chapter) {
// create a dom
$addDom = new DOMDocument();
// load the chapter
$addDom->load($chapter);
// if here is a root node in the loaded xml
if ($addDom->documentElement) {
// append to the result dom
$dom->documentElement->appendChild(
// after importing the document element to the result dom
$dom->importNode($addDom->documentElement, TRUE)
);
}
}
echo $dom->saveXml();