Simple XML to parse general recordset - php

Question

I am trying to find a way to iterate through an XML recordset containing a namespace. However, I don't know the field names in advance. Sample XML is below.
<?xml version="1.0" encoding="utf-8"?>
<string xmlns="http://www.site.com/SMART/Updates">
<NewDataSet>
<record>
<FIELD1>data1</FIELD1>
<FIELD2>data2</FIELD2>
<FIELD3>data3</FIELD3>
</record>
<record>
<FIELD1>data1</FIELD1>
<FIELD2>data2</FIELD2>
<FIELD3>data3</FIELD3>
</record>
</NewDataSet>
Again, I won't know the field names in advance. I need read the namespace, find the name of the root element ("NewDataSet", in this case) and then need to get the field names and values of the individual elements. I have tried to use $xml->getname(), and $xml->xpath('\') to find the root element name, but been unable to crack it.

Answer 1

(as discussed in Chat)
Plain DOM functions are the best way to process XML.
Demo or code:
<?php
header('Content-Type: text/plain');
$xml = <<<END
<?xml version="1.0" encoding="utf-8"?>
<string xmlns="http://www.site.com/SMART/Updates">
<NewDataSet>
<record>
<FIELD1>data1</FIELD1>
<FIELD2>data2</FIELD2>
<FIELD3>data3</FIELD3>
</record>
<record>
<FIELD1>data1</FIELD1>
<FIELD2>data2</FIELD2>
<FIELD3>data3</FIELD3>
</record>
</NewDataSet>
</string>
END;
$dom = new DOMDocument;
$dom->preserveWhiteSpace = false;
$dom->normalize();
$dom->loadXML($xml);
echo 'Root element name: ' . $dom->firstChild->firstChild->tagName . PHP_EOL;
echo 'Number of child elements: ' . count($dom->firstChild->firstChild->childNodes) . PHP_EOL;
echo '=====' . PHP_EOL . PHP_EOL;
echo print_node($dom->firstChild->firstChild);
function print_node($node, $level = 0, $prev_level = 0) {
$result = '';
if($node->hasChildNodes()) {
foreach($node->childNodes as $subnode) {
$result .= str_repeat(' ', $level) . $node->tagName . ' =>' . PHP_EOL;
$result .= print_node($subnode, $level + 1, $level) . PHP_EOL;
}
} else {
if(trim($node->nodeValue) !== '') {
$result .= str_repeat(' ', $level) . '**Data: ' . trim($node->nodeValue) . PHP_EOL;
}
}
return $result;
}
?>
Output:
Root element name: NewDataSet
Number of child elements: 1
=====
NewDataSet =>
record =>
FIELD1 =>
**Data: data1
record =>
FIELD2 =>
**Data: data2
record =>
FIELD3 =>
**Data: data3
NewDataSet =>
record =>
FIELD1 =>
**Data: data1
record =>
FIELD2 =>
**Data: data2
record =>
FIELD3 =>
**Data: data3

Answer 2

Your XML is invalid, but assuming the string tag is closed after the </NewDataSet> tag:
You can get the namespaces declared in the document using getDocNamespaces().
$xml = simplexml_load_string($xmlfile);
$namespaces = $xml->getDocNamespaces(); //array of namespaces
$dataset = $xml->children(); //first child (NewDataSet)
echo $dataset->getName(); //NewDataSet
$records = $dataset->children();
$i = 0;
$result = array();
foreach ($records as $key => $value) {
foreach ($value as $fieldName => $fieldData) {
$result[$i][$fieldName] = (string)$fieldData;
}
$i++;
}
var_dump($result);
Now $result contains an array that is easier to read and contains the rows :
array(2) {
[0]=> array(3) {
["FIELD1"]=> string(5) "data1"
["FIELD2"]=> string(5) "data2"
["FIELD3"]=> string(5) "data3"
}
[1]=> array(3) {
["FIELD1"]=> string(5) "data1"
["FIELD2"]=> string(5) "data2"
["FIELD3"]=> string(5) "data3"
}
}

Answer 3

Looking at the chat transcript posted in another answer, it looks like the element actually contains a string which is an escaped XML document. So there is exactly one element in the outer document, called <string>. It has no children, just content. (This looks remarkably like someone using ASP.net's service-builder.)
So the step you are missing is unescaping this inner XML to treat as a new XML document:
// Parse the outer XML, which is just one <string> node
$wrapper_sx = simplexml_load_string($wrapper_xml);
// Extract the actual XML inside it
$response_xml = (string)$wrapper_sx;
// Parse that
$response_sx = simplexml_load_string($response_xml);
// Now handle the XML
$tag_name = $response_sx->getName();
foreach ( $response_sx->children() as $child )
{
// Etc
}
// see http://github.com/IMSoP/simplexml_debug
simplexml_tree($response_sx, true);

Answer 4

I don't actually understand what you problem is, in your said real-life XML you gave in PHP chat, there are no namespaces involved (and even if!).
Just read out the tag-name from the document element:
# echoes NewDataSet / string (depending on which XML input)
echo dom_import_simplexml($simplexml)->ownerDocument->documentElement->tagName;
If you have actually an XML document inside another XML document, you can do the following:
// load outer document
$docOuter = new DOMDocument();
$docOuter->loadXML($xmlString);
// load inner document
$doc = new DOMDocument();
$doc->loadXML($docOuter->documentElement->nodeValue);
echo "Root element is named: ", $doc->documentElement->tagName, "\n";
Or if you prefer SimpleXML:
echo "Root element is named: ",
simplexml_load_string(simplexml_load_string($xmlString))->getName()
;