php get node value from xml based on other node value - php

Question

I have currently an xml file that is formatted as follows:
<SKUQuestions>
<SKUQuestion>
<Tag>FrontCamaraWorks</Tag>
<Question>Does the front Camera Work?</Question>
<Answer>Yes</Answer>
</SKUQuestion>
<SKUQuestion>
<Tag>BackCamaraWorks</Tag>
<Question>Does the Rear Camera Work?</Question>
<Answer>No</Answer>
</SKUQuestion>
</SKUQuestions>
I am currently getting the info from the "answer" nodes by calling where it occurs in the xml for example:
$qFrontCameraWorks = $data['skuQuestions']->SKUQuestion[4];
$data['frontCameraWorks'] = str_replace("'", "\'", $qFrontCameraWorks->Answer);
my problem is the xml files don't always come to me with the questions in the same order.
So, I was wanting to figure a way to query within a "SKUquestion" node if the "tag" is one thing then it would return the value of the "answer" node within that same SKUquestion node.
for example if the tag is "FrontCamaraWorks" then $data['frontCameraWorks'] is yes.

Answer 1

Simply run an XPath query expression. As information, XPath is a declarative language used to reference parts of XML documents. PHP's SimpleXMLElement class can run XPath queries returned in arrays:
$xmlstr = "<SKUQuestions>
<SKUQuestion>
<Tag>FrontCamaraWorks</Tag>
<Question>Does the front Camera Work?</Question>
<Answer>Yes</Answer>
</SKUQuestion>
<SKUQuestion>
<Tag>BackCamaraWorks</Tag>
<Question>Does the Rear Camera Work?</Question>
<Answer>No</Answer>
</SKUQuestion>
</SKUQuestions>";
# LOAD STRING XML
$xml = new SimpleXMLElement($xmlstr);
# RUN XPATH QUERY
$queryResult = $xml->xpath('//SKUQuestion[Tag="FrontCamaraWorks"]/Answer');
# OUTPUT VALUE
echo $queryResult[0];
# Yes
Alternatively, you can use PHP's DOMXPath using its query() method which returns a DOMNodelist (not array):
# LOAD STRING XML
$xmldoc = new DOMDocument();
$xmldoc->loadXML($xmlstr);
# INITIALIZE AND RUN QUERY
$xpathvar = new DOMXPath($xmldoc);
$queryResult = $xpathvar->query('//SKUQuestion[Tag="FrontCamaraWorks"]/Answer');
# ITERATE DOM NODE LIST
foreach($queryResult as $result){
echo $result->nodeValue;
}
# Yes

Answer 2

You can refer this link for the details: http://php.net/manual/en/function.simplexml-load-file.php.
I am giving you an example also for your understanding.
Convert the XML string ($buffer) into a simplified array ignore attributes and grouping child-elements with the same names:
function XML2Array(SimpleXMLElement $parent)
{
$array = array();
foreach ($parent as $name => $element) {
($node = & $array[$name])
&& (1 === count($node) ? $node = array($node) : 1)
&& $node = & $node[];
$node = $element->count() ? XML2Array($element) : trim($element);
}
return $array;
}
$xml = simplexml_load_string($buffer);
$array = XML2Array($xml);
$array = array($xml->getName() => $array);
Result:
Array
(
[SKUQuestions] => Array
(
[SKUQuestion] => Array
(
[Tag] =>
[Question] =>
[Answer] =>
)
)
)
Then, you can refer the answer tag irrespective of your skuquestions ordering. I hope it will help.