Why my php function does not receive the array I sent to it by ajax

Question

I have an array that I obtain by means of an ajax query, and I need to send it to a function of a php file to manipulate it and use the elements that are in the indexes of the array.

This is the php function:

class ControladorCompraEfectivoYTarjeta {

   public function ctrCompraEfectivo(){

      if(isset($_POST["registroUsuario"])){

          if(preg_match('/^[a-zA-ZñÑáéíóúÁÉÍÓÚ ]+$/', $_POST["registroUsuario"]) &&
             preg_match('/^([0-2][0-9]|3[0-1])(\/|-)(0[1-9]|1[0-2])\2(\d{4})$/', $_POST["registroCalendario"]) &&
             preg_match('/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,4})+$/', $_POST["registroEmail"]) &&
             preg_match('/^(?:\D*\d){2,4}\D*$/', $_POST["registroDireccion"]) &&
             preg_match('/^[0-9]{7,12}$/', $_POST["registroTelefono"])) {

             //here is where I need to manipulate the array and be able to perform other tasks with its elements

}

The php function already receives POST variables, for that reason there are some validations inside. When trying to send the array with JSON.stringify by AJAX, if I do a print_r ($_POST) the browser tells me that only the variables I'm validating at the beginning of the function arrive, but nothing in the array

The array I get from an AJAX request, within this Javascript function:

$("#btnCheckout").click(function(){ 

    var total = $(".valorTotalCompra").html();
    var envio = $(".valorTotalEnvio").html();
    var subtotal = $(".valorSubtotal").html();
    var titulo = $(".valorTitulo");
    var cantidad = $(".valorCantidad");
    var valorItem = $(".valorItem");

    var idProducto = $('.cuerpoCarrito button, .comprarAhora button');

    var tituloArray = [];
    var cantidadArray = [];
    var valorItemArray = [];
    var idProductoArray = [];

    for(var i = 0; i < (titulo.length/2); i++){

        tituloArray[i] = $(titulo[i]).html();
        cantidadArray[i] = $(cantidad[i]).html();
        valorItemArray[i] = $(valorItem[i]).html();
        idProductoArray[i] = $(idProducto[i]).attr("idProducto");

    }

    var datos = new FormData();

    datos.append("total",total);
    datos.append("envio",envio);
    datos.append("subtotal",subtotal);
    datos.append("tituloArray",tituloArray);
    datos.append("cantidadArray",cantidadArray);
    datos.append("valorItemArray",valorItemArray);
    datos.append("idProductoArray",idProductoArray);

    $.ajax({

         url:rutaOculta+"ajax/carritoEfectivo.ajax.php",
         method:"POST",
         data: datos,
         success:function(response){
            console.log("The response is: ", response) }

    });

})

What do I have to do now, to be able to send this array to the function of the php file and be able to manipulate it?

If I do console.log of the array in Javascript, it looks like this:

array(3) {
  [0]=>
  array(4) {
    ["titulo"]=>
    string(25) "Crea aplicaciones con PHP"
    ["cantidad"]=>
    string(1) "1"
    ["valorItem"]=>
    string(2) "10"
    ["idProducto"]=>
    string(3) "400"
  }
  [1]=>
  array(4) {
    ["titulo"]=>
    string(29) "Vestido Clásico - 36 - negro"
    ["cantidad"]=>
    string(1) "7"
    ["valorItem"]=>
    string(2) "77"
    ["idProducto"]=>
    string(1) "3"
  }
  [2]=>
  array(4) {
    ["titulo"]=>
    string(29) "Aprende Javascript desde Cero"
    ["cantidad"]=>
    string(1) "1"
    ["valorItem"]=>
    string(2) "10"
    ["idProducto"]=>
    string(3) "401"
  }
}

Answer 1

You're receiving an array of three elements in the $_POST. Iterate through them to get at the indexes you're targeting:

foreach($_POST as $i => $el) {
      if(isset($el["registroUsuario"])){...

And currently you're looking for an index that doesn't exist, at least in the data sample you posted:

$_POST["registroUsuario"]

Your code has to use the same index names that are sent in the data.

$_POST[0]["titulo"]

do a

echo "<pre>";
print_r($_POST);
echo "</pre>"; 

to get some insight as to how your data looks when received on the server. This should tell you how to handle it properly.