How can I tell which button was clicked in a PHP form submit?

Question

Hey all,

I have several buttons on my page, but I'm not sure how to tell which one was clicked. Here's the markup for my two buttons:

<input type="submit" id="btnSubmit" value="Save Changes" />
<input type="submit" id="btnDelete" value="Delete" />

Thanks in advance, Sonny

Answer 1

In HTML:

<input type="submit" id="btnSubmit" name="btnSubmit" value="Save Changes" />
<input type="submit" id="btnDelete" name="btnDelete" value="Delete" />

In PHP:

if (isset($_POST["btnSubmit"])){
  // "Save Changes" clicked
} else if (isset($_POST["btnDelete"])){
  // "Delete" clicked
}

Answer 2

Are you asking in php or javascript.

If it is in php, give the name of that and use the post or get method, after that you can use the option of isset or that particular button name is checked to that value.

If it is in js, use getElementById for that

Answer 3

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    //something posted

    if (isset($_POST['btnDelete'])) {
        // btnDelete
    } else {
        //assume btnSubmit
    }
}

You should always assume the first submit button to appear in the form html code. The reason is that some browsers will not send the name/value of any submit buttons if the user submits the form without clicking a button, or having the form focus on a button when they press enter. ANother case when the button name/value may not be sent is if you use certain javascript methods to submit a form.

A lot of people submit forms by simply using the enter key while focus is on an input field. It's important to pay attention to this detail, otherwise your can really frustrate your users when they submit a form, yet "nothing happens" and their data is lost.