Ajax登录响应错误

Question

i'm traying to login with ajax and php, in that situation i'm logging succesfuly actually. But i'm trying to make an alert and refresh the page when logged in. When i attempt to login, its gives me error and no refreshing. But if i refresh the page, i see i have session in php. I don't understand why.

Here is my code;

<script>

$(document).ready(function(){  
    $('#login_btn').click(function(){  
       var email = $('#email').val();  
       var password = $('#password').val();  


      if(email == '' || password == ''){
        $("#login_error").html("*** Please enter your email / password");
      }else{              
          $('#login_error').html("<strong class='text-success'>Validating...</strong>");

                $.ajax({
                url: "login.php",
                method: "post",
                data:{email:email, password:password},
                success: function(data){
                if (data === 'yes') {
                    window.location.reload();
                }else{
                    $('#login_error').html("<strong class='text-danger'>ERROR...</strong>");
                }
            }
                });

      }
    });
 }); 
</script>

login php:

<?php  
session_start();
include ('../config/setup.php'); #database connection


if(isset($_POST['email'])){
$q = "SELECT * FROM users WHERE email = '$_POST[email]' AND password = '$_POST[password]'";
$r = mysqli_query($dbc, $q);

if(mysqli_num_rows($r) > 0){
    $_SESSION['email'] = $_POST['email'];
    echo "yes";
}else{
    echo "no";
}
}
?>  

Html: (Using login form inside a modal)

<div class="modal-body">

<div class="form-horizontal">
  <div class="form-group">
    <label for="email" class="col-sm-4 control-label">Email</label>
    <div class="col-sm-8">
      <input type="email" class="form-control" name="email" id="email" placeholder="Account Email">
    </div>
  </div>
  <div class="form-group">
    <label for="password" class="col-sm-4 control-label">Password</label>
    <div class="col-sm-8">
      <input type="password" class="form-control" name="password" id="password" placeholder="Account Password" >
    </div>
  </div>

  <div class="form-group">   
    <div class="col-sm-1"></div>
     <div align="center" class="col-sm-10">
      <button name="login_btn" id="login_btn" class="btn btn-success btn-block text-center"><span id="loader_before" class="glyphicon glyphicon-log-in" aria-hidden="true"></span><i id="loader" class="fa fa-spinner fa-spin fa-x fa-fw"></i> Log in to Account</button>
      </div>
      <div class="col-sm-1"></div>    
  </div>
</div>

<div align="center" class="container-fluid">   
<h6><a href="#"><strong class="text-danger">Forgot your password? Click here..</strong></a></h6>
</div>  
<h5><div id="login_error" class="text-warning"></div></h5>
</div>  

Answer 1

You just need to update your if block in response as below `

if (data === 'yes') {
    alert("You message here!");
    window.location.reload();
}else{
    $('#login_error').html("<strong class='text-danger'>ERROR...</strong>");
}

`

Answer 2

When you call echo on php, it will write the value, but not return it. That's the problem. You are not returning "yes" or "no" from login.php, you're just doing echo, which will only write the value but not return it to the caller. The ajax call is waiting for a response to process it with the 'success' callback. Since login.php is not returning anything, it will always fall into the else clause. The solution is to change this on login.php

if(mysqli_num_rows($r) > 0){
$_SESSION['email'] = $_POST['email'];
    return "yes";
}else{
    return "no";
}