跨域请求，但POST为空

Question

I need to implement a cross-domain POST request. Using this code, everything worked fine in the same domain. But when I moved the backend to another domain - all stopped working! Therefore, there can be typos. There can be only where the error is related to the cross-domain request. I try send POST request using ajax and JSONP:

function requestToServer(url, success, myObjects) 
{
    $.ajax({
        type: "POST",
        crossDomain: true,
        dataType: 'jsonp',
        jsonp: 'jsonp_callback',
        url: url,
        data: "arrObjects=" + JSON.stringify(myObjects),
        success: function(data)
        {
            success(data);
        },
        error: function()
        {
            alert('Server connection error!!!');
        }
    });
}

and server-script, where send data:

<?php

header('Access-Control-Allow-Origin: '.$_SERVER['HTTP_ORIGIN']);
header('Access-Control-Allow-Methods: POST, GET, OPTIONS');
header('Access-Control-Max-Age: 1000');
header('Access-Control-Allow-Headers: Content-Type');

include 'connection.php';

$arrObjects = json_decode($_POST['arrObjects']);


$title = $arrObjects->title;
$msg = $arrObjects->msg;
$lat = $arrObjects->lat;
$lon = $arrObjects->lon;

$query = "INSERT INTO `geo_markers` (`id`, `title`, `description`, `lat`, `lon`) 
VALUES (NULL, '{$title}', '{$msg}', '{$lat}', '{$lon}')";

$res = mysqlQuery($query);

echo $_GET['jsonp_callback'].'({"success":true});';

mysql_close();
?>

but $_POST is empty. But $_GET takes values $_POST. If I check $_POST using var_dump, it is array(0), $_GET contains all send data!

What's wrong here? What went wrong can it be?

Answer 1

您不能发出jsonp POST请求，只能使用GET完成jsonp，这就是为什么所有数据都在$ _GET中的原因。

Answer 2

JSONP doesn't work by POST request. JSONP works by the caller generating a script tag with a url which hopefully with generate a bit of script invoking a callback function with the data passed, as needed. if you want true cross domain posting, you'll have to implement Cross-Origin Resource Sharing (CORS) functionality with something to handle OPTIONS requests (maybe like with http://remysharp.com/2011/04/21/getting-cors-working/ , but I confess, I didn't even fully scan it, I just looked over it to see that likely documents the basic, necessary functionality).

Answer 3

You have send JSON formatted since you are using jsonp format. try json_encode before you echo data.

Also keep in mind that when you make a cross domain jsonp call, JSONP isn't AJAX, it's merely a dynamic script element. You can't do a POST with a dynamic script element. There's no place to put the POST data. So You will have to use GET method.

Also keep in mind that you can use below format

$.getJSON(url + "?callback=?", null, function(data) {

});

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