试图将JSON.stringify转换为PHP数组

Question

This script is getting all of my contacts in JSON and show the results in a div

window.location.href = 'gonative://contacts/getAll?callback=contacts_callback';
        function contacts_callback(data) {
        document.getElementById('demo').innerHTML = JSON.stringify(data);
        }

I want to convert the whole JSON to be displayed in PHP array and echo the first contact name:

$soJSON = "<div id='demo'></div>";
$soArray = json_decode($soJSON, true);
echo $soArray["contacts"][0]["givenName"];

This way i don't see anything but if i change the $soJSON to a demo code than it works.

I need the result to be from my contacts phone and not from the demo.