How to pass multiple checkbox values to php

Question

Currently i have a HTML form that collects some metadata about some files, and each user as to fill some fields. I want to register some keywords about the data. I could ask them to write the keywords by hand on a normal text box, but i would prefer to have a list of checkboxes of about 10/15 values.

Then i need to pass only the checked values to a PHP file, using $_POST. My problem is that i assign a variable to those values, and then i call that variable in a DOM event. I´m generating a XML file, and currently i have the HTML ready to register these keywords in text input. I understand how to create the checkboxes, and pass them as an array to PHP., by reading other questions here. But i can´t understand how to pass this array to a $dom->createElement situation, and preferably separated by commas.

PHP

//Pull data from HTML form
$keywordsString = $_POST['keywords'];

// Creates xml document
$dom = new DOMDocument();
    $dom->encoding = 'utf-8';
    $dom->xmlVersion = '1.0';
    $dom->formatOutput = true;

$xmlFileName = 'example_example.xml';

// Adds metadata to xml
$metadata = $dom->createElement('MD_Metadata');

    $idInfo = $dom->createElement('identificationInfo');
        $descriptiveKeywords = $dom->createElement('descriptiveKeywords');
                $CharacterString = $dom->createElement('CharacterString', $keywordsString);
                $descriptiveKeywords->appendChild($CharacterString);
            $idInfo->appendChild($descriptiveKeywords);
    $metadata->appendChild($idInfo);

$dom->appendChild($metadata);

$dom->save($xmlFileName);

I can´t figure out how to pass checkbox values to that $keywordsString , but separated by commas. The rest i can understand and write, using the other questions about this kind of issue.

Thanks in advance for all help provided.

You'd need to use a `foreach` and the inputs need to be able to accept multiple arrays, I.e.: `[]`. — Funk Forty Niner, Dec 16 '19 at 17:05
Thank you. The ```foreach``` is a bit confusing, but i'll look into it with more attention. The multiple array was on my mind but wasn´t sure on how to proceed about it. — d_araujo, Dec 16 '19 at 17:08
Welcome. Have a look at [this Q&A](https://stackoverflow.com/q/18421988/1415724) here on Stack Overflow. I submitted an answer in there myself, but there are other answers in that same question that you can have a look at. It will / should give you a good idea as to how to go about this. — Funk Forty Niner, Dec 16 '19 at 17:10
That Q&A is really enlightening, even with a quick read. I will focus on it, thanks again. — d_araujo, Dec 16 '19 at 17:16

csandreas1 · Accepted Answer · 2019-12-17T21:28:09.310

Your html should look like this:

<form action="" method="post">
  <input name="choice[]" type="checkbox" value="1" /> 
  <input name="choice[]" type="checkbox" value="2" /> 
  <input name="choice[]" type="checkbox" value="3" /> 
  <input name="choice[]" type="checkbox" value="4" /> 
  <input type="submit" value="order" />
</form>

In PHP, you can iterate over using foreach loop. Place the below code at the top of your html form:

A small note from basics, when posting data via post method, you need to apply Post redirect get design pattern to prevent form re-submissions.

If the data you are sending is not sensitive, you can do it via get request.

<?php
    if($_POST):
    foreach($_POST['choice'] as $val)
    {
    echo $val . "<br>";
    }
    endif;
?>

How to pass multiple checkbox values to php

1 Answers1