Make checkbox return false when unchecked - php

Question

I have a form looking like:
<form>
<input type"checkbox" name="checked[(unique_id)]">
<input type"checkbox" name="checked[(unique_id)]">
<input type"checkbox" name="checked[(unique_id)]">
<input type"checkbox" name="checked[(unique_id)]">
</form>
The number of checkboxes will variate from time to time so when processing this data with PHP I have to loop the _POST['checked'] array.
My problem is that I want to take actions both when a checkbox is checked and when it's not. But only the the checked checkboxes will be added to the _POST['checked'] array.

Answer 1

<form>
<input type="checkbox" key="1"/>
<input type="hidden" name="checked[1]" value="false">
<input type="checkbox" key="2"/>
<input type="hidden" name="checked[2]" value="false">
<input type="checkbox" key="3"/>
<input type="hidden" name="checked[3]" value="false">
<input type="checkbox" key="4"/>
<input type="hidden" name="checked[4]" value="false">
</form>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script>
$(document).ready(function () {
$('[key]').change(function () {
var key = $(this).attr('key');
$($('[name="checked[' + key + ']"]')).val($(this).is(':checked') ? 'true' : 'false');
});
});
</script>
here is what i'm doing
i'm using two inputs one is checkbox without name so it won't be sent to php
, the other is hidden won't be shown to the user but it is what will be sent to php
then with jquery when the user check the box jquery change the value of the hidden input to true and when uncheck it change the value to false
so the value will always be send to the php with value true or false as string
you can change the value you want to send to php by changing this
.is(':checked')?'true':'false')
to something like that .is(':checked')?1:0) to send 1 and 0 instead of true and false
another solution is rybo111 solution
<input type="hidden" name="check" value="false">
<input type="checkbox" name="check" value="true">
it will send the two options but if the checkbox is checked it will override the first option
but it is not reliable 100% and it will send more data to the server
read more about that in POSTing Form Fields with same Name Attribute
so if you want to use simple solution without js use the "html only"
if you want 100% reliable solution use the "js"

Answer 2

Here's a technique I've seen before:
<input type="hidden" name="check" value="false">
<input type="checkbox" name="check" value="true">
The reason this works is because when values with the same name are sent more than once, only the last value is accepted.
In my opinion, a better way is to simply use isset($_POST['...']) or in_array($_POST['...']).

Answer 3

Add value="true" to each checkbox input element.
And change your PHP code to :
$checked_arr = [];
foreach($_POST["checked"] as $checked){
if($checked == "true"){
// do what you want to do
}
}

Answer 4

Another Solution is server-side solution that I think is too fast and easy.
client side:
Just use fresh HTML :
<input type="checkbox" name="checked1" value="value_checked" ... />
server side:
make global function like this:
function getVal(&$var, $default = '') {
if (!isset($var) || empty($var) || is_null($var))
$var = $default;
return $var;
}
then use where you want to read some value that you don't know is set or not.
like this:
$checked_value = getVal($_POST["checked1"],false);
or
$checked_value = getVal($_POST["checked1"],"value_not_checked");
I hope useful to another one.

Answer 5

This is best approach according to my experience
<input type="hidden" name="check" value="false">
<input type="checkbox" name="check" value="true">