PHP DOMDocument generates namespace declarations on wrong elements - php

Question

Here's the PHP code Im using from http://pastebin.com/7FBysx2X
$doc = new DOMDocument('1.0', 'UTF-8');
$xns = 'http://www.w3.org/2000/xmlns/';
$mns = 'http://example.com/aBc/2/';
$ons = 'http://example.com/test/2005/something';
$ns = 'http://example.com/main/';
$firstChild = $doc->createElement('firstChild');
$firstChild->setAttributeNS($xns, 'xmlns:cns1', $mns);
$firstChild->setAttributeNS($xns, 'xmlns:i', $ons);
$elements = $doc->createElementNS($mns, 'cns1:elements');
for($i = 0; $i < 3; $i++) {
$e = $doc->createElementNS($mns, 'cns1:element');
for($k = 0; $k < 2; $k++) {
$r = rand(100, 999);
$value = round(($r*rand(1,9))/rand(1,9), 2);
$ce = $doc->createElementNS($mns, "cns1:elementValue$r", $value);
$e->appendChild($ce);
}
$elements->appendChild($e);
}
$firstChild->appendChild($elements);
$otherTag = $doc->createElementNS($mns, 'cns1:otherTag', 'some_value');
$emptyTag = $doc->createElementNS($mns, 'cns1:emptyTag');
$emptyTag->setAttributeNS($ons, 'i:nil', 'true');
$firstChild->appendChild($otherTag);
$firstChild->appendChild($emptyTag);
$main = $doc->createElementNS($ns, 'main');
$main->appendChild($firstChild);
$doc->appendChild($main);
header('Content-Type: text/xml');
echo $doc->saveXML();
The above code generates XML like this:
<?xml version="1.0" encoding="UTF-8"?>
<main xmlns:cns1="http://example.com/aBc/2/" xmlns:i="http://example.com/test/2005/something" xmlns="http://example.com/main/">
<firstChild xmlns:cns1="http://example.com/aBc/2/" xmlns:i="http://example.com/test/2005/something">
<cns1:elements>
<cns1:element>
<cns1:elementValue303>101</cns1:elementValue303>
<cns1:elementValue608>304</cns1:elementValue608>
</cns1:element>
<cns1:element>
<cns1:elementValue735>147</cns1:elementValue735>
<cns1:elementValue901>4505</cns1:elementValue901>
</cns1:element>
</cns1:elements>
<cns1:otherTag>some_value</cns1:otherTag>
<cns1:emptyTag i:nil="true"/>
</firstChild>
</main>
Document is expected to look like this:
<?xml version="1.0" encoding="UTF-8"?>
<main xmlns="http://example.com/main/">
<firstChild xmlns:cns1="http://example.com/aBc/2/" xmlns:i="http://example.com/test/2005/something">
<cns1:elements>
<cns1:element>
<cns1:elementValue303>101</cns1:elementValue303>
<cns1:elementValue608>304</cns1:elementValue608>
</cns1:element>
<cns1:element>
<cns1:elementValue735>147</cns1:elementValue735>
<cns1:elementValue901>4505</cns1:elementValue901>
</cns1:element>
</cns1:elements>
<cns1:otherTag>some_value</cns1:otherTag>
<cns1:emptyTag i:nil="true"/>
</firstChild>
</main>
The problem is at <main> tag. Why it has cns1 and i namespace declarations? They should be only at firstChild element. What i need to change to get needed structure?

Answer 1

This is caused by adding child nodes to node which is not already added to document.
Changing code to this:
$doc = new DOMDocument('1.0', 'UTF-8');
$doc->formatOutput = true;
$xns = 'http://www.w3.org/2000/xmlns/';
$mns = 'http://example.com/aBc/2/';
$ons = 'http://example.com/test/2005/something';
$ns = 'http://example.com/main/';
$main = $doc->createElementNS($ns, 'main');
$doc->appendChild($main);
$firstChild = $doc->createElement('firstChild');
$firstChild->setAttributeNS($xns, 'xmlns:cns1', $mns);
$firstChild->setAttributeNS($xns, 'xmlns:i', $ons);
$doc->getElementsByTagName('main')->item(0)->appendChild($firstChild);
$elements = $doc->createElementNS($mns, 'cns1:elements');
$doc->getElementsByTagName('firstChild')->item(0)->appendChild($elements);
for($i = 0; $i < 3; $i++) {
$e = $doc->createElementNS($mns, 'cns1:element');
$doc->getElementsByTagName('elements')->item(0)->appendChild($e);
for($k = 0; $k < 2; $k++) {
$r = rand(100, 999);
$value = round(($r*rand(1,9))/rand(1,9), 2);
$ce = $doc->createElementNS($mns, "cns1:elementValue$r", $value);
$doc->getElementsByTagName('element')->item($i)->appendChild($ce);
}
}
$otherTag = $doc->createElementNS($mns, 'cns1:otherTag', 'some_value');
$emptyTag = $doc->createElementNS($mns, 'cns1:emptyTag');
$emptyTag->setAttributeNS($ons, 'i:nil', 'true');
$doc->getElementsByTagName('firstChild')->item(0)->appendChild($otherTag);
$doc->getElementsByTagName('firstChild')->item(0)->appendChild($emptyTag);
echo $doc->saveXML();
Produces XML which looks exactly like your expected one. Maybe there is more 'pretty' or 'proper' way to do this, but for sure this one is working.