PHP Issue with isset function

Question

I'm making a contact form for my website that uses php to send the inputted information to my email.

My issue is that the isset php function returns false. I'm not sure why this is.

Here is my php code (the outputted result is "not sent")

<?php

if (isset($_POST['submit'])){
    $name = $_POST['name'];
    $subject = $_POST['subject'];
    $mailFrom = $_POST['mail'];
    $message = $_POST['message'];

    $mailTo = "btrorapps@gmail.com";
    $headers = "From: " .$mailFrom;
    $txt = "You have received an email from " .$name.".\n\n".$message;

    if (mail($mailTo, $subject, $txt, $headers)){
        echo "<h1>sent successfully</h1>";
    } else {
        echo "<h1>something went wrong</h1>";
    }
} else {
    echo "not sent";
}

?>

Here is my form code

<form action="contactform.php" method="post" enctype="text/plain">
     <label for="name">Name</label>
     <input type="text" name="name" placeholder="Full name.." maxlength="20" required>

     <label for="mail">Email</label>
     <input type="text" name="mail" placeholder="Your email.." 
      pattern="[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z{2,}$" required>

     <label for="subject">Subject</label>
     <input type="text" name="subject" maxlength="25" placeholder="Subject..">

     <label for="message">Message</label>
     <input type="text" name="message" placeholder="Message.." style="height:170px" 
      maxlength="150" required>

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

i think you need to remove enctype , read this (https://stackoverflow.com/questions/7628249/method-post-enctype-text-plain-are-not-compatible) — anehme, Jul 04 '20 at 20:27

score 5 · Accepted Answer · answered Jul 05 '20 at 01:32

There is nothing wrong with isset function. It is not even a PHP-related issue.

It is all about form submission encoding. There are 3 valid encoding types for forms:

application/x-www-form-urlencoded (default)
multipart/form-data
text/plain

You're using the third one, which has documented like:

Payloads using the text/plain format are intended to be human readable. They are not reliably interpretable by computer, as the format is ambiguous (for example, there is no way to distinguish a literal newline in a value from the newline at the end of the value).

You're not getting any POST variables since PHP doesn't populate $_POST when using enctype="text/plain".

In the docs of $_POST superglobal:

An associative array of variables passed to the current script via the HTTP POST method when using application/x-www-form-urlencoded or multipart/form-data as the HTTP Content-Type in the request.

Being said that, you can still read raw data from the request body.

$data = file_get_contents('php://input');

But you'll get the whole data as a string (plain text).

And last but not least, be careful, php://input is not available with enctype="multipart/form-data".

I changed from text/plain to multipart/form-data and it worked flawlessly. Thanks!!! — btror, Jul 05 '20 at 02:26

Onimusha · Answer 2 · 2020-07-05T10:21:40.543

1

Don't use isset($_POST['submit']) that's referencing a submit button in case there's more than one submit button on the form as the button is not always pressed. This has caused me issues in the past.

Pressing enter on any field will submit the form with the first submit button available.

Use one of the fields. In your case you can use if (isset($_POST['name'])){

edited Jul 05 '20 at 10:21

answered Jul 04 '20 at 20:23

Onimusha

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This is not correct. Submitting the form with any mean should send all of its input elements including `type=input` https://output.jsbin.com/havison – SaidbakR Jul 04 '20 at 20:30
Okay, I see what you mean Onimusha. I changed the line to if (isset($_POST['name'])). I see what you are saying, but unfortunately it isn't working. The result is still "not sent" – btror Jul 04 '20 at 21:43
1

@SaidbakR That's incorrect. A submit button will not be sent if it wasn't clicked i.e. enter was pressed on a text field. Try it. Every other field will be sent. A submit button won't be. See for example https://stackoverflow.com/questions/22579616/send-value-of-submit-button-when-form-gets-posted – Onimusha Jul 05 '20 at 09:33
@SaidbakR Your jsbin had errors but I tested properly and you are right, the first submit is sent. I posted this answer because I use multiple submit buttons and had this issue. As the first submit button is sent my answer is wrong and I've updated it but now it's unrelated so I'll leave it to moderators to leave or remove. – Onimusha Jul 05 '20 at 10:20

PHP Issue with isset function

2 Answers2