Extracting data from xml using php - php

Question

I'm trying to grab specific data from a XML file using php.
My goal is to feed a function a "number" and get the corresponding price back.
Eg. if I input the number "swv8813" it will return the price "603.00", and if I input the number "swv8814" it will return "700.00".
How can I do this?
<?xml version="1.0" encoding="iso-8859-1" ?>
<Feed>
<Title>CompanyName</Title>
<Email>info#CompanyName.com</Email>
<Products>
<Product>
<Id>4635</Id>
<Number>swv8813</Number>
<Title><![CDATA[&Tradition - Bellevue AJ2 - Floor Lamp White]]></Title>
<Description><![CDATA[]]></Description>
<Category><![CDATA[Lighting]]></Category>
<Stock>0</Stock>
<Price>603.00</Price>
<Discount>0.00</Discount>
<Created>0000-00-00 00:00:00</Created>
</Product>
<Product>
<Id>4635</Id>
<Number>swv8814</Number>
<Title><![CDATA[&Tradition - Bellevue AJ2 - Floor Lamp Black]]></Title>
<Description><![CDATA[]]></Description>
<Category><![CDATA[Lighting]]></Category>
<Stock>0</Stock>
<Price>700.00</Price>
<Discount>0.00</Discount>
<Created>0000-00-00 00:00:00</Created>
</Product>
</Products>
</Feed>

Answer 1

Use this:
$xmlstr = "<Feed>
<Title>CompanyName</Title>
<Email>info#CompanyName.com</Email>
<Products>
<Product>
<Id>4635</Id>
<Number>swv8813</Number>
<Title><![CDATA[&Tradition - Bellevue AJ2 - Floor Lamp White]]></Title>
<Description><![CDATA[]]></Description>
<Category><![CDATA[Lighting]]></Category>
<Stock>0</Stock>
<Price>603.00</Price>
<Discount>0.00</Discount>
<Created>0000-00-00 00:00:00</Created>
</Product>
<Product>
<Id>4635</Id>
<Number>swv8814</Number>
<Title><![CDATA[&Tradition - Bellevue AJ2 - Floor Lamp Black]]></Title>
<Description><![CDATA[]]></Description>
<Category><![CDATA[Lighting]]></Category>
<Stock>0</Stock>
<Price>700.00</Price>
<Discount>0.00</Discount>
<Created>0000-00-00 00:00:00</Created>
</Product>
</Products>
</Feed>";
$feed = new SimpleXMLElement($xmlstr);
function findPrice($feed, $id){
foreach($feed->Products->Product as $product){
if($product->Number == $id){
return $product->Price;
}
}
return null;
}
echo findPrice($feed, 'swv8813');
echo "\n";
echo findPrice($feed, 'swv8814');
See it working at 3v4l.org script

Answer 2

With DOM and Xpath you can fetch the value directly:
$id = 'swv8813';
$xml = file_get_contents('php://stdin');
$document = new DOMDocument();
$document->loadXml($xml);
$xpath = new DOMXpath($document);
$expression = sprintf(
'number(/Feed/Products/Product[Number="%s"]/Price)',
str_replace(["\00", '"'], '', $id)
);
var_dump($expression, $xpath->evaluate($expression));
Output:
string(54) "number(/Feed/Products/Product[Number="swv8813"]/Price)"
float(603)
The id value is not allowed to have zero bytes or double quotes. A simple str_replace takes care of that.
The expression ...
...fetches all Product nodes...
/Feed/Products/Product
...filters them by their Number child...
/Feed/Products/Product[Number="swv8813"]
...gets the Price children for the filtered nodes...
/Feed/Products/Product[Number="%s"]/Price
...and casts the first found Price to a number.
number(/Feed/Products/Product[Number="swv8813"]/Price)