PHP - 连续两次输入输入后的处理

Question

I have a problem with my form.

I have an HTML Form as follows:

<form action="index.php" method="post">
    <input type="text" name="text" id="text">
    <input type="submit" value="Send" name="send">
</form>

Now my problem is:

Every time I process this form for the first time, it should output an error. The error has to be shown every time, if this is the first try.

If I enter the same input value twice, it should succeed.

I thought about setting a session variable $_SESSION['first_visit] if I'm processing the form for the first time.

I also thought about saving the $_POST['text'] - Value into Session but it's being overwritten every time.

Thank you for your answers.

Answer 1

<?php

extract($_POST);

if( isset($send) )
{
    if( $fired <= 0 )
    {
        $fired++;
        echo "Nope, error. send again to succeed";
    }
    else
    {
        echo "Yay success";
    }
}

?>

<form action="" method="post">
    <input type="hidden" name="fired" value="<?php echo isset($fired) ? $fired : 0 ?>">
    <input type="text" name="text" id="text">
    <input type="submit" value="Send" name="send">
</form>

Here's some quick and dirty snippet. We set a hidden input field with an initial value of 0 and count it up everytime the form has been send. The only thing to do afterwards is to check if the value of the hidden field is bigger than 0