无法使用PHP从Ajax POST获取JSON

Question

I am sending JSON in a POST to my PHP script. I'm unable to get the object values from the JSON. The format of the POST is as follows:

[{"name":"amount","value":"12"}]

Javascript

("#idForm").submit(function(e) {

      var url = "post.php"; // the script where you handle the form input.
      var formData = JSON.stringify($("#idForm").serializeArray());
      alert(formData);

      $.ajax({
        type: "POST",
        url: url,
        data: formData,
        dataType: 'json',
        success: function(dataresponse) {
          document.getElementById("orderamount").innerHTML = dataresponse.orderamount;
        }
      });

PHP

if(!empty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest') {

$data = array();

$json = json_decode(file_get_contents('php://input'), true);
$data['orderamount'] = $json['amount'];
//this works 
//$data['orderamount'] = '12345';

echo json_encode($data); 
}

Any idea what I'm doing wrong?

Answer 1

We can parse JSON Array, and dictionaries inside it, like this,

<?php
$json = "[{\"name\":\"amount\",\"value\":\"12\"}]";
$dec = json_decode($json,true);

for($idx = 0; $idx < count($dec); $idx++){
    $obj = (Array)$dec[$idx];
    echo $obj["name"];
}
?>

Answer 2

In your example json there are two parameters, name and value.

[{"name":"amount","value":"12"}]

You should use $json['name'] instead of $json['amount'] . You can try the following example

if(!empty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest') {
$data = array();
$json = json_decode(file_get_contents('php://input'), true);
if($json['name']=='amount') {
$data['orderamount'] = $json['value'];
}
echo json_encode($data); 
}

Answer 3

请在发送请求之前尝试

 setRequestHeader("Content-type", "application/x-www-form-urlencoded");

Answer 4

In Response

document.getElementById("orderamount").innerHTML = dataresponse['orderamount'];