issues in writing xml files in php - php

Question

I wrote a code in which i m writing new xml files depending on content of one xml file i have with me right now.
In xml file from which i m reading,there are 14 fragments with 3 -4 nodes each.I have to right 7 new xml files in this case,each containing 2 fragments from first file.
So that all xml files after writing should have 2 fragments each,totalling all to 14 fragments when all files combined.
But the code is not giving me the correct output
following is the code
<?php
$docOutput = new DOMDocument("1.0");
$root = $docOutput ->createElement("data");
$docOutput ->appendChild($root);
if(!$xml=simplexml_load_file('xmlfile.xml')){
trigger_error('Error reading XML file',E_USER_ERROR);
}
$array1=array();
$x=0;
foreach($xml as $syn)
{
for($i=$x*2;$i<($x+1)*2;$i++)
{
//$array1[] = $syn->productId;
echo $i;
echo "<br />";
echo $syn->productId;
$id = $docOutput ->createElement("PID");
$idText = $docOutput ->createTextNode($syn->productId);
$id->appendChild($idText);
$title = $docOutput ->createElement("PNAME");
$titleText = $docOutput ->createTextNode($syn->productname);
$title->appendChild($titleText);
$book = $docOutput ->createElement("Product");
$book->appendChild($id);
$book->appendChild($title);
$root->appendChild($book);
}
$docOutput ->formatOutput = true;
echo "<xmp>". $docOutput ->saveXML() ."</xmp>";
$docOutput ->save("mybooks$x.xml") or die("Error");
$x++;
}
//echo count($array1, COUNT_RECURSIVE);
?>
Following is one fragment of file,which i m reading
<?xml version="1.0"?>
<data>
<Product>
<PID>SGLDN7XJ2FPZH8G8</PID>
<PNAME>Miami Blues Aviator Sunglasses</PNAME>
</Product>
</data>
There are 14 Product fragments in file from which i m reading.After writing i should get 7 files with two fragments each.
Please help in correcting the code

Answer 1

The problem you've got is less with the code to read/write the XML but more just with the basic looping logic.
What you perhaps actually want is while iterating over the product nodes, to move the iteration ahead so you can put two product elements together. This works with a SimpleXMLIterator:
$xml = simplexml_load_string($buffer, 'SimpleXMLIterator');
foreach ($xml as $product) {
// output current element
printf("-+-%s\n", $product->asXML());
// move to next element
$xml->next();
$product = $xml->current();
// output next element
printf(" \- %s\n\n", $product->asXML());
}
With this XML input:
<?xml version="1.0"?>
<data>
<Product>1</Product>
<Product>2</Product>
<Product>3</Product>
<Product>4</Product>
</data>
The example outputs:
-+-<Product>1</Product>
\- <Product>2</Product>
-+-<Product>3</Product>
\- <Product>4</Product>
Online-Demo: https://eval.in/172918