How to Send POST Requests with PHP cURL and jQuery AJAX Form

1. Using PHP cURL

The following function builds a query string from an associative array, initializes a cURL session, sets the necessary options, executes the request, and returns the response.

function curlPost($url, $params)
{
    $postData = '';
    foreach ($params as $k => $v) {
        $postData .= $k . '=' . $v . '&';
    }
    rtrim($postData, '&');
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_HEADER, false);
    curl_setopt($ch, CURLOPT_POST, count($postData));
    curl_setopt($ch, CURLOPT_POSTFIELDS, $postData);
    $output = curl_exec($ch);
    curl_close($ch);
    return $output;
}

echo curlPost("http://test.com", array('name' => "tank"));

Previously many people used cURL to fetch email address books, but this method is no longer allowed by some services.

2. Submitting a Form with jQuery Form and AJAX

First, download jquery.form.js. Then use the following JavaScript to intercept the form submission and send it via AJAX.

$('#testform').submit(function() {
    $(this).ajaxSubmit({
        type: 'post', // submission method
        dataType: "json", // expected response type
        url: 'your url', // target URL
        success: function(data) {
            // handle returned data (usually JSON)
            alert('Submission successful!');
        }
    });
    $(this).resetForm(); // reset the form after submission
    return false; // prevent default form submission
});

On the server side, set the appropriate CORS headers if the request comes from a different origin.

header("Access-Control-Allow-Origin: *"); // allow all origins
// or restrict to a specific domain
header("Access-Control-Allow-Origin: http://www.test.com");