PHP表单，包含验证和成功消息

Question

I am creating a from and doing the validation with PHP. I want to hide the form and show a success message once all validation is complete. This is the code I am using, can you tell me why the form is always hiding and success message is not shown:

      <?php
// defining variables and set to empty values
$nameErr = "";
$emailErr = "";
$numberErr = "";

$name = "";
$email = "";
$number = "";
$comment = "";

function test_input($data) {
  $data = trim($data);
  $data = stripslashes($data);
  $data = htmlspecialchars($data);
  return $data;
} 

if ($_SERVER["REQUEST_METHOD"] == "POST") {
  if (empty($_POST["name"])) {
    $nameErr = "Name is required";
  } else {
    $name = test_input($_POST["name"]);
    // check if name only contains letters and whitespace
    if (!preg_match("/^[a-zA-Z ]*$/",$name)) {
      $nameErr = "Only letters and white space allowed"; 
    }
  }

  if (empty($_POST["email"])) {
    $emailErr = "Email is required";
  } else {
    $email = test_input($_POST["email"]);
    // check if e-mail address is well-formed
    if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
      $emailErr = "Invalid email format"; 
    }
  }

  if (empty($_POST["number"])) {
    $numberErr = "Contact Number is required";
  } else {
    $number = test_input($_POST["number"]);
    // check if number only contains letters and whitespace
    if (!preg_match("/^[a-zA-Z ]*$/",$number)) {
      $numberErr = "Only letters and white space allowed"; 
    }
  }

  if (empty($_POST["comment"])) {
    $comment = "";
  } else {
    $comment = test_input($_POST["comment"]);
  }

  function form_submission_success(){
    echo 'Form submitted';
  }

  function submit_database(){

  }


  form_submission_success();
} else {
?>

        <p><span class="error">* required field.</span></p>
            <form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">  
              Full Name: <input type="text" name="name" value="<?php echo $name;?>">
              <span class="error">* <?php echo $nameErr;?></span>

              <br><br>

              Contact E-mail: <input type="text" name="email" value="<?php echo $email;?>">
              <span class="error">* <?php echo $emailErr;?></span>

              <br><br>

              Contact Number: <input type="text" name="number" value="<?php echo $number;?>">
              <span class="error">* <?php echo $numberErr;?></span>

              <br><br>

              Comment: <textarea name="comment" rows="5" cols="40"><?php echo $comment;?></textarea>
              <br><br>

              <input type="submit" name="submit" value="Submit">  
          </form>

          <?php } ?>

With the same logic I will then submit all entries into a database, however once all valdiation is complete.

Answer 1

Please try this, may be you need more modifications but is could be a basic idea

<?php// defining variables and set to empty values
$nameErr = "";
$emailErr = "";
$numberErr = "";
$name = "";
$email = "";
$number = "";
$comment = "";
function test_input($data) {
$data = trim($data);
$data =stripslashes($data);
$data = htmlspecialchars($data);
return $data;
}
if ($_SERVER["REQUEST_METHOD"] == "POST") {
function form_submission_success($msg = 'Form submitted'){
echo $msg.'<br>';
}   
if (empty($_POST["name"])) {
$nameErr = "Name is required";
form_submission_success($nameErr);
} else {
$name = test_input($_POST["name"]);
// check if name only contains letters and whitespace
if (!preg_match("/^[a-zA-Z ]*$/",$name)) {
$nameErr = "Only letters and white space allowed";
form_submission_success($nameErr);
}
}
if (empty($_POST["email"])) {
$emailErr = "Email is required";
form_submission_success($emailErr);
} else {
$email = test_input($_POST["email"]);
// check if e-mail address is well-formed
if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
$emailErr = "Invalid email format";
form_submission_success($emailErr);
}
}
if (empty($_POST["number"])) {
$numberErr = "Contact Number is required";
form_submission_success($numberErr);
} else {
$number = test_input($_POST["number"]);
// check if number only contains letters and whitespace
if (!preg_match("/^[a-zA-Z ]*$/",$number)) {
$numberErr = "Only letters and white space allowed";
form_submission_success($numberErr);
}
}
if (empty($_POST["comment"])) {
$comment = "";
} else {
$comment = test_input($_POST["comment"]);
}
function submit_database(){
}
} else {
?>
<p><span class="error">* required field.</span></p>
<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">  
Full Name: <input type="text" name="name" value="<?php echo $name;?>"
<span class="error">* <?php echo $nameErr;?></span>
<br><br>
Contact E-mail: <input type="text" name="email" value="<?php echo $email;?>">
<span class="error">* <?php echo $emailErr;?></span>
<br><br>
Contact Number: <input type="text" name="number" value="<?php echo $number;?>">
<span class="error">* <?php echo $numberErr;?></span>
<br><br>
Comment: <textarea name="comment" rows="5" cols="40"><?php echo $comment;?></textarea>
<br><br>
<input type="submit" name="submit" value="Submit">  
</form>
<?php } ?>