jQuery AJAX与PHP通过JSON返回（登录表单）

Question

I don't know what I do wrong..

I have 2 files: login.php index.php

<script type="text/javascript">  
$(document).ready(function(){  
$('#btnLogin').bind('click', loginToWebsite);
});
function loginToWebsite(){
     $.ajax({  
     url: "login.php",
      type: "POST",  
      data: "username=" + $("#username").val()+"&password=" + $("#password").val(),
    datatype:"json",
      success: function(status)
      {  
        if(status.success == false) 
        {  
            $("#loginform").effect("shake", {times:2}, 100); 
            $("#login_message")  
                .attr('class', 'ui-state-error')  
                .html('<strong>ERROR</strong>: Your details were incorrect.<br />');  
        } 
        else { 
                 $("#login_message")  
                .attr('class', 'ui-state-highlight')  
                .html('<strong>PERFECT</strong>: You may proceed. Good times.<br />');  
            }  
      }  
    });  
} 
</script> 

login.php gile looks this way:

<?php
if (isset($_POST['username'])&& isset($_POST['password']))
{
    if (login ($_POST['username'], $_POST['password'])){
        $data = array("success" => true);
        echo json_encode($data);
    }
    else {
        $data = array("success" => false);
        echo json_encode($data);
    }
}?>

But i get undefined back from login.php (via json)

If I try to alert(status.success) it prints undefined

And I can see i the header that the username and password are getting send to the login.php page.

The PHP function login() is implemented elsewhere (and returns true or false)

Answer 1

It seems the value pass to javascript through variable "status" is a string. So you have to convert the string to json object. To convert string to json object use following script. Use the latest jquery library because older one using different functions to convert string to json.

    var obj = jQuery.parseJSON(status);
    alert(obj.success);