Accessing a specific XML element using xpath in PHP 7.x

Question

Ok so I have some XML data.

$mydata = <<<XML
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE fmresultset PUBLIC "-//FMI//DTD fmresultset//EN" "https://HIDDEN:443/fmi/xml/fmresultset.dtd">
<fmresultset xmlns="http://www.filemaker.com/xml/fmresultset" version="1.0">    
    <resultset count="1" fetch-size="1">
        <record mod-id="27" record-id="754">
            <field name="a_Constant_c">
                <data>1</data>
            </field>
            <field name="a_Sch_ID_pk">
                <data>100060</data>
            </field>
            <field name="a_SchoolHead_pk">
                <data>100060_1</data>
            </field>
            <field name="b___Data_____________">
                <data/>
            </field>
            <field name="b_1Name_School_Code_t">
                <data>PJA</data>
            </field>
            <field name="b_1Name_School_t">
                <data>Palmetto</data>
            </field>
            <field name="b_1Name_SchoolHead_t">
                <data>John Doe</data>
            </field>
            <field name="b_Ad_Address1_t">
                <data/>
            </field>
            <field name="b_Ad_Address2_t">
                <data>123 Main St.</data>           
        </record>
    </resultset>
</fmresultset>
XML;

Now what I want to do is basically be able to read the value of the data from a specific field and assign it to a variable.

So far I have something like this...

$xml = simplexml_load_string($mydata);

Now I want to be able to assign let's say the data in the field name b_1Name_School_Code_t (which is PJA)

So I think it should be something like this

$school = $xml->resultset->record->field->data;
echo "School Name: ".$school;

Then I would like to see on the screen

School Name: PJA

So what I am missing to be able to make this happen?

Answer 1

You are only getting to the first field element in your example, which is why you get 1 . Instead, loop through all the field elements, and stop when you get to the one you need:

$xml = simplexml_load_string($mydata);
$fields = $xml->resultset->record->field;
foreach ($fields as $field) {
    if ((string) $field->attributes()->name === "b_1Name_School_Code_t") {
        echo "School name: ".$field->data; // School name: PJA
        break;
    }
}

Demo

I use SimpleXMLElement::attributes() to get the name attribute of the element (note the cast to string , otherwise you get an SimpleXMLElement )

However, it would make more sense to use XPath to go directly to the element you're after:

$xml = simplexml_load_string($mydata);
$xml->registerXPathNamespace("fmresultset", "http://www.filemaker.com/xml/fmresultset");
$node = $xml->xpath("//fmresultset:resultset/fmresultset:record/fmresultset:field[@name='b_1Name_School_Code_t']");
var_dump($node[0]->data); // PJA

Demo

Notice the namespace registration and the accessing of the first element, since xpath() returns an array of SimpleXMLElement s