How to access the form's 'name' variable from PHP

Question

I\'m trying to create a BMI calculator. This should allow people to use either metric or imperial measurements.

I realise that I could use hidden tags to solve my pr

Answer 1

As petervandijck.com pointed out, this code may be susceptible to XSS attacks if you have it behind some kind of log-in system or have it embedded in other code.

To prevent an XSS attack, where you have written:

<?php echo "$weight"; ?>

You should write instead:

<?php echo htmlentities($weight); ?>

Which could even be better written as:

<?=htmlentities($weight); ?>

Answer 2

In the form submitting button (id method of form is post):

<input type="submit" value="save" name="commentData">

In the PHP file:

if (isset($_POST['commentData'])){
    // Code
}

Answer 3

Use a unique value on the submit button for each form like so

index.html

<form method="post" action="bat/email.php">
    <input type="text" name="firstName" placeholder="First name" required>
    <input type="text" name="lastName" placeholder="Last name" required>
    <button name="submit" type="submit" value="contact">Send Message</button>
</form>

<form method="post" action="bat/email.php">
    <input type="text" name="firstName" placeholder="First name" required>
    <input type="text" name="lastName" placeholder="Last name" required>
    <button name="submit" type="submit" value="support">Send Message</button>
</form>

email.php

<?php
    if (isset($_POST["submit"])) {
      switch ($_POST["submit"]) {
          case "contact":
              break;
          case "support":
              break;
          default:
              break;
      }
    }
?>

Answer 4

I had a similar problem which brought me to this question. I reviewed all the preceding answers but ultimately I ending up figuring out my own solution. I hope it helps someone else with this same issue:

<form name="ctc_form" id="ctc_form" action='' method='get'>

<input type="hidden" name="form_nm" id="form_nm">

<button type="submit" name="submit" id="submit" onclick="document.getElementById('form_nm').value=this.closest('form').name;">Submit</button>

</form>

It seamlessly and efficiently accomplishes the following:

• Passes the form name attribute via a hidden input field, without using the fallible value attribute of the submit button.
• Works with both GET and POST methods.
• Requires no additional, independent JavaScript.

Answer 5

You could just give a name to the submit button and do what needs to be done based on that. I have several forms on a page and do just that. Pass the button name and then if button name = button name do something.

Answer 6

Only the names of the form fields are submitted, the name of the form itself is not. But you can set a hidden field with the name in it.