Download and merge multiple XML files with PHP, Foreach and Dom - php

Question

I'm breaking my tooths since a week with this problem : i'm trying to download and merge dynamicly multiples xml files with an API. I can download all the files but i can't merge them without having multiple roots elements... It's frustrating and i don t find any suggestion. Here is my code :
<?php
$fileout = 'file.xml';
unlink($fileout);
$baseurl="https://websitewithapi.com/";
$topcategories=array("COOL","DRIVE","FUN");
foreach ($topcategories as $topcategory) {
$url_cata_test="https://websitewithapi.com/&filters=topcategory:$topcategory&limit=1";
$jsontest = file_get_contents($url_cata_test);
$arrtest=json_decode($jsontest);
$items=$arrtest->pagination->count;
$pagemax=ceil($items/250);
$pagetest= range(0,$pagemax);
foreach ($pagetest as $page) {
$url_cata="$baseurl&filters=topcategory:$topcategory&offset=$page&limit=250";
echo "Cat en cours d import: ".$topcategory."\n";
echo "Page en cours d import: ".$page."\n";
echo "URL Cata: $url_cata \n";
};
$dom = new DOMDocument();
$dom->appendChild($dom->createElement('superdeals'));
$files= array($url_cata);
foreach ($files as $filename) {
$addDom = new DOMDocument();
$addDom->load($filename);
if ($addDom->documentElement->getElementsByTagName('products')) {
foreach ($addDom->documentElement->getElementsByTagName('product') as $node) {
$dom->documentElement->appendChild(
$dom->importNode($node, TRUE)
);
}
}
$dom->formatOutput = true;
file_put_contents($fileout, $dom->saveXML(), FILE_APPEND);
}
};
?>
I got always the same problem with "associate" files in the same file but with multiple roots ! Is there a thing i miss ?
Thank you.

Answer 1

Simply initialize the DOM object and save its file output outside of all four foreach loops. Currently you are using FILE APPEND for each iteration which is not an XML DOM method but simply concatenates text content. Continue to grow your XML tree within the loops and then output the singular XML once without any file appends.
$fileout = 'file.xml';
unlink($fileout);
// INITIALIZE DOM TREE
$dom = new DOMDocument();
$dom->appendChild($dom->createElement('superdeals'));
...
foreach ($topcategories as $topcategory) {
...
foreach ($pagetest as $page) {
...
foreach ($files as $filename) {
...
foreach ($addDom->documentElement->getElementsByTagName('product') as $node) {
$dom->documentElement->appendChild(
$dom->importNode($node, TRUE)
);
}
}
}
}
// OUTPUT DOM TREE
file_put_contents($fileout, $dom->saveXML());

Answer 2

It looks like you are adding root element called "superdeals" to your document, and then adding the contents of each file at the root level.
You need to add the contents of each file as a child of the "superdeals" element, not as a child of the document.
Save the root node:
$root = $dom->appendChild($dom->createElement('superdeals'));
then instead of
$dom->documentElement->appendChild($dom->importNode($node, TRUE))
add child to the root node (not the document node):
$root->appendChild($dom->importNode($node, TRUE))
Document element can contain nodes apart from the root element, such as entity definitions, processing instructions and so on.