decoding php not working - php

Question

i want to post a json object to php.
var user = {username:"test", password:"test", name:"test",
email:"test#hotmail.com"};
var str_json = JSON.stringify(user);
$.ajax({
url: '/register_API.php',
type: 'post',
contentType: "application/json; charset=utf-8",
success: function (data) {
console.log('success');
},
data: user
});
}
In php i want to insert it into mysql:
$data = file_get_contents('php://input');
$json = json_decode($data,true);
$username = $json['username'];
$password = $json["password"];
$email = $json['email'];
$insertSql = "INSERT INTO users (username, password, email)
VALUES ('$username', '$password', '$email');";
The $data string contains: username=test&password=test&name=test&email=test%40hotmail.com, but i can't get the variable by decoding...
Thanks in advance!

Answer 1

Change data: user to data: str_json and then
change $data = file_get_contents('php://input');
to $data = $_POST['data']

Answer 2

You're not sending a JSON string, you're sending a Javascript object which jQuery is translating to a set of parameters in the outgoing POST request. Your data will be available to PHP in $_POST - no need to decode it first.
Look for it like this:
$username = $_POST['username'];
$password = $_POST["password"];
$email = $_POST['email'];

Answer 3

I think you want to send raw JSON as text and have that be in the post body and not treated as an encoded form.
In this case I think your PHP code is right. Send the stringified JSON as you are, but set the data type to dataType: "text".
I think you will be able to read it with
$data = file_get_contents('php://input');

Answer 4

I think you can use
//works like explode, but splits your data where finds "=" and "&" too.
$output = preg_split( "/ (=|&) /", $data);
This will return an array of your data. where:
$output[0]="Username";
$output[1]="test";
This can be useful if you have fixed data.