I can't understand why the data object seems doesn't exist at php server side page.
Angular
$http.post("serverside.php", {"data1":"okpass"}).success(function(data, status, header, config){
console.log(data);//
console.log(status);//202
console.log(header);//function (c){a||(a=nc(b));return c?a[O(c)]||null:a}
});
PHP
if( isset($_POST["data1"]) && $_POST["data1"] == "okpass" ){
echo "It works!";
exit(0);
}