在创建PHP会话和重定向之前显示消息

Question

I am trying to show a success message before creating a PHP session and redirecting to another page. The problem is that if I use the sleep() function, once I submit the form it just sleeps for 3 seconds and then redirects the same to the next page without showing the message. Here is the bit of code where I am having this trouble:

if(mysqli_query($connect, $query)){
    echo '<div class="alert alert-success" role="alert">Foi registado com sucesso!</div>';
    sleep(3);
    $_SESSION['email'] = $user_email;
    header("Location: areacliente.php");
}
}else{
    $erro .="O registo falhou!";
}

Answer 1

What you are trying to do can be done using JavaScript. Also as noted by the commenters, you may want to either have a button or write the message on the next page. It looks like the message isn't critical, so auto-disappearing is probably not a problem:

Option 1 - JavaScript Redirect:

Use essentially the same script you have now, but use javascript to redirect.

if(mysqli_query($connect, $query)):
    # Assign before message
    $_SESSION['email'] = $user_email ?>
    <!-- write message -->
    <div class="alert alert-success" role="alert">Foi registado com sucesso!</div>
    <!-- create timeout -->
    <script>
    setTimeout(function(){
        window.location = 'areacliente.php';
    }, 3000);
    </script>
<?php else:
    $erro .="O registo falhou!";
endif;

---

Option 2 - Message to Next:

Assign the session and just redirect to the next page, then show the message on that page and auto-hide it on countdown (or not).

/whatever_file_this_is.php

# Just set this as default false
$_SESSION['success'] = false;
if(mysqli_query($connect, $query)){
    # Set this to true for the next page
    $_SESSION['success'] = true;
    # Set the email as you have it
    $_SESSION['email'] = $user_email;
    # Redirect
    header("Location: areacliente.php");
    # Stop so rest of the script doesn't run
    exit;
}
else {
    $erro .="O registo falhou!";
}

/areacliente.php

<?php
# Check if the session success is true
if(!empty($_SESSION['success'])):
    # Remove it since it's being used now
    unset($_SESSION['success']); ?>
    <!-- Add an id to this div -->
    <div class="alert alert-success" role="alert" id="success-msg">Foi registado com sucesso!</div>
    <!-- count down and hide the message after 3 sections -->
    <script>
    setTimeout(function(){
        document.getElementById('success-msg').style.display = 'none';
    },3000);
    </script>
<?php endif ?>