Php : Post a list of checkboxes - php

Question

After a SQL request, I obtain a form which contains a list of data, with checkboxes at the end of each line. The goal is the following. If the user checks some of them, the line will be deleted in the database when the form will be submitted.
I name my checkboxes like this, with my SQL request results, so my Php script could find the line to delete:
<input type="checkbox" name="chk[<?echo '/'.'$t[datetr]'.'/'.'$t[beneficiaire]'.'/'.'$t[objet]'.'/'.'$t[montant]';?>]">
My goal is to get all the checkboxes values with $_POST to my Php script. But even with this...
foreach ($_POST as $key => $value) {
echo "<tr>";
echo "<td>";
echo $key;
echo "</td>";
echo "<td>";
echo $value;
echo "</td>";
echo "</tr>";
}
...my php script does not seem to get the checkboxes values... Did I do something wrong ? Thanks for help.

Answer 1

Aside from the other (entirely accurate) comments about unchecked boxes not being passed with the HTTP request - you have a couple of issues with your actual PHP.
<?echo '/'.'$t[datetr]'.'/'.'$t[beneficiaire]'.'/'.'$t[objet]'.'/'.'$t[montant]';?>
Firstly, your echo is wrong; it should probably be <?php echo or <?= rather than <?echo (although that might work with short start tags enabled).
Secondly, Apostrophes in PHP are non-interpolated string literals (i.e. '$t[objet]' will literally be treated as the string '$t[objet]' not the variable).
Finally, assuming $t is an array, your associative indexes need to have quotes or they'll be interpreted as constants - which is likely to throw an error.
I think what you want could be written as:
<?= "/{$t['datetr']}/{$t['beneficiaire']}/{$t['objet']}/{$t['montant']}"; ?>
Once you've sorted that out, the $_POST['chk'] data should be set properly and it'll be an associative array as you're expecting.
Then a foreach($_POST['chk'] as $key => $value) { ... } loop should work... though, of course none of your inputs actually have values at the moment.

Answer 2

When using <input type="checkbox" name="foo" value="42"/>, the variable foo=42 is sent only if the checkbox is checked. When the box is not checked, nothing is sent at all.
If you need some 0/1 information, i suggest you use either a <select> or a couple of <input type="radio"> tags instead:
<input type="radio" name="foo" value="1"/> Yes
<input type="radio" name="foo" value="0"/> No

Answer 3

Blank checkboxes do not get posted to the receiving script, only checked ones do. To get around this have a corresponding set of hidden fields, and set their values to something like "ON" or "OFF" depending on how the checkboxes are clicked. You will probably want to use the onClick event, determine of the box is clicked or not then set the appropriate hidden field, i.e.
Checkbox_One Hidden_One
Checkbox_Two Hidden_Two etc.
When you post the form, have your script ignore the checkboxes, and just process the hidden fields.

Answer 4

Something to remember when doing these multi-checkboxes is that when you submit, it will be interpreted in PHP as an array, in your case $_POST['chk'] will be an array of checked checkboxes.
However, you should also make sure you give the checkboxes a value, even if just a 1.
When handling your POST, initially just try using a var_dump($_POST); die(); to see what the data looks like.

Answer 5

use the code below:
foreach ($_POST['chk'] as $key => $value) {
echo "<tr>";
echo "<td>";
echo $key;
echo "</td>";
echo "<td>";
echo $value;
echo "</td>";
echo "</tr>";
}

Answer 6

If you name all your checkboxes like this name="boxArray[]" it will create an array named $_POST["boxArray"] when the form is submitted.
Then you can do your foreach loop to display the values:
foreach ($_POST["boxArray"] as $item) {
echo "<tr>";
echo "<td>";
echo $item;
echo "</td>";
echo "</tr>";
}
To add to this, if you want to delete only the items checked then for each checkbox assign the record's ID as its value:
<input type="checkbox" name="boxArray[]" value="RECORD ID">
Now when you run your foreach loop only the checked boxes will post values so you change the code to delete each item in the array:
foreach ($_POST["boxArray"] as $item) {
//SQL TO DELETE RECORD WHERE ID = $item;
}