使用ajax将JSON发送到PHP

Question

我想以json格式将一些数据发送到php并在php中进行一些操作.我的问题是我无法通过ajax将json数据发送到我的php文件.请帮助我,我该怎么做.我试过这种方式..

<script>
$(function (){
 $("#add-cart").click(function(){
    var bid=$('#bid').val();
    var myqty=new Array()
    var myprice=new Array()

    qty1=$('#qty10').val();
    qty2=$('#qty11').val();
    qty3=$('#qty12').val();

    price1=$('#price1').val();
    price2=$('#price2').val();
    price3=$('#price3').val();

    var postData = 
                {
                    "bid":bid,
                    "location1":"1","quantity1":qty1,"price1":price1,
                    "location2":"2","quantity2":qty2,"price2":price2,
                    "location3":"3","quantity3":qty3,"price3":price3
                }
    var dataString = JSON.stringify(postData);

    $.ajax({
            type: "POST",
            dataType: "json",
            url: "add_cart.php",
            data: {myData:dataString},
            contentType: "application/json; charset=utf-8",
            success: function(data){
                alert('Items added');
            },
            error: function(e){
                console.log(e.message);
            }
    });
});
});
</script>

在PHP中我使用:

if(isset($_POST['myData'])){
 $obj = json_decode($_POST['myData']);
 //some php operation
}

当在php文件中添加print_r($ _ POST)时,它在firebug中显示array(0){}.

Answer 1

失去了contentType: "application/json; charset=utf-8",.您没有向服务器发送JSON,而是发送正常的POST查询(恰好包含JSON字符串).

这应该使你的工作成功.

事情是,你根本不需要使用JSON.stringify或json_decode在这里.做就是了:

data: {myData:postData},

然后在PHP中:

$obj = $_POST['myData'];

Answer 2

那是因为$_POST预先填充了表单数据.

要获取JSON数据(或任何原始输入),请使用php://input.

$json = json_decode(file_get_contents("php://input"));

Answer 3

使用json和ajax将javascript obj发送到php:

JS:

var dataPost = {
   "var": "foo"
};
var dataString = JSON.stringify(dataPost);

$.ajax({
   url: 'server.php',
   data: {myData: dataString},
   type: 'POST',
   success: function(response) {
      alert(response);
   }
});

在php中使用该对象:

$obj = json_decode($_POST["myData"]);

echo $obj->var;

Answer 4

如果要通过$_POST变量获取值，则不应将contentType指定为"application/json"，而应使用默认值"application/x-www-form-urlencoded; charset=UTF-8"：

JavaScript：

var person = { name: "John" };

$.ajax({
    //contentType: "application/json", // php://input
    contentType: "application/x-www-form-urlencoded; charset=UTF-8", // $_POST
    dataType : "json",
    method: "POST",
    url: "http://localhost/test/test.php",
    data: {data: person}
})
.done(function(data) {  
    console.log("test: ", data);
    $("#result").text(data.name);
})
.fail(function(data) {
    console.log("error: ", data);
});

PHP：

<?php

// $_POST

$jsonString = $_POST['data'];

$newJsonString = json_encode($jsonString);
header('Content-Type: application/json');
echo $newJsonString;

否则，如果您要将JSON从JavaScript发送到PHP：

JavaScript：

var person = { name: "John" };

$.ajax({
    contentType: "application/json", // php://input
    //contentType: "application/x-www-form-urlencoded; charset=UTF-8", // $_POST
    dataType : "json",
    method: "POST",
    url: "http://localhost/test/test.php",
    data: person
})
.done(function(data) {  
    console.log("test: ", data);
    $("#result").text(data.name);
})
.fail(function(data) {
    console.log("error: ", data);
});

PHP：

<?php

$jsonString = file_get_contents("php://input");
$phpObject = json_decode($jsonString);

$newJsonString = json_encode($phpObject);
header('Content-Type: application/json');
echo $newJsonString;