HTML PHP (Why does not return value?)

Question

I was actually trying to retrieve the input submit button value. But I don't know why it does not work. Can anyone help me?

When the user click the buttons, the button's value will be send to the next page.

<?php
include('connect.php');

// Create connection
$conn = new mysqli(DB_HOST, DB_USER, DB_PASSWORD, DB_DATABASE);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

$sql = "SELECT * FROM userauth";
$result = mysqli_query($conn, $sql);

if (mysqli_num_rows($result) > 0) {
    // output data of each row
    while ($row = mysqli_fetch_assoc($result)) {
        ?>

        <html>
            <head>
                <title>GAF APPS</title>  
            </head>
            <body>
                <form method="post" action="branch.php">
                    <input type="submit" name="submit" value="<?php echo $row["Company"]; ?>">
                </form>
            </body>
        </html>

        <?php
    }
} else {
    echo "0 results";
}
$conn->close();
?>

Here is where I was going to retrieve the value:

<?php
if (isset($_POST['action'])) {
    echo '<br />The ' . $_POST['submit'] . ' submit button was pressed<br />';
}
?>

so, where's the "next" page? edit: or did you just edit that now? — Funk Forty Niner, Oct 10 '17 at 13:17
Em sorry I accidentally press the post question button. I just edited. — Inori Yuzuriha, Oct 10 '17 at 13:18
You're not sending any input named `action`, hence `isset($_POST['action'])` returns `false`. — roberto06, Oct 10 '17 at 13:19
you should be getting an undefined index notice. what happens when you add an `else { echo "Not set"; }`? Error reporting's your friend here. — Funk Forty Niner, Oct 10 '17 at 13:19
@Inori Yuzuriha Add an input hidden with true value inside your form and name="action" and this code should run. — , Oct 10 '17 at 13:21
@Fred-ii- Are you sure that `isset($_POST['action'])` will trigger an undefined index notice ? I thought the point of `isset` was to avoid that (well, at least one of the points) ? — roberto06, Oct 10 '17 at 13:23
I reopened the question, it was a bad close on my part and I apologize for it. However, as I said in my previous comment, the latter part of it would have thrown you an "Not set". I have posted a community wiki answer below, where rep is not gained. — Funk Forty Niner, Oct 10 '17 at 13:33

score 1 · Accepted Answer · edited Oct 10 '17 at 13:33

1

You don't have an input named "action", therefore the isset() will never happen which is why you did not get an error for it

Having added an else condition for it, would have shown you that instead.

edited Oct 10 '17 at 13:33

user229044

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answered Oct 10 '17 at 13:33

Funk Forty Niner

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score -1 · Answer 2 · answered Oct 10 '17 at 15:14

When debuging in PHP I tend the use the shotgun approach and output everything that could be remotely interesting and then narrow it down.

So when looking at parsing form variables use echo var_export($_GET, true) or vardump($_GET).

Not sure if GET or POST? Use _REQUEST which has both in 1 variable.

Use the HTML tag to make it more readable and htmlspecialchars() to convert characters that would normally be invisible because of your browser.

Using those will make it far easier to see what you are doing with your form.

So to answer the above question: Look at the the mentioned request variables and determine by looking at the HTML and the code if the expected variables should be parsed and send by the browser when the submit button is pressed.

AND

See if the values actually received by PHP will have the expected outcome when handled.

Try to keep those 2 things separate, because what is in your HTML now does not mean it was there when you parsed the form. That's a bit of a bind when developing with PHP/HTML and forms, when you change the code and do not fully reload, but just press Submit on the form: the code that will parse the current form will be changed, but the contents of the form parsed are the ones that where loaded in your browser and might be out dated.

HTML PHP (Why does not return value?)

2 Answers2