php - value of checkbox not working correctly

Question

I have this checkbox:

<label>Maintenance Mode: <small>Tick to enable/disable.</small></label>
<input type="checkbox" name="maintenance" value="1" <?php echo $maintenance; ?> >

I get the data from my database. So, if maintenance is enabled in my database, then the checkbox will be checked on. That happens like this:

if($sdata['maintenance']==1):
    $maintenance="checked='checked'";
else: 
    $maintenance="";
endif;

The problem is, whenever I want to disable maintenance, it doesn't update the database. It will still be set to "1".

This is how I post it:

$maintenance = inputFilter($_POST['maintenance']);

My database table have two columns:

setting_name and setting_value. In this case, it would be:

maintenance and 1

I update it like this:

foreach($_POST as $key => $value)
{
  $value = inputFilter($value);
  mysql_query("UPDATE settings SET setting_value='$value' where setting_name='$key' limit 1")
  or die(mysql_error());
}

Whenever I uncheck the checkbox, and save the settings, nothing happens. I even tried to echp $maintenance from the post, and when it's unchecked, the value is 0.

Anyone have any idea what is causing this?

Webbrowser doesn't send checkbox in the POST request then is non-checked. — Siper
– Siper, Commented Jan 3, 2014 at 11:52

Alex Barroso · Accepted Answer · 2014-01-03 11:51:21Z

5

Non-checked checkboxes are not send in the POST request, so its key is not in $_POST

You should check if the checkbox name exists.

if(!isset($_POST['maintenance'])) {
     // Checkbox is unchecked
}

answered Jan 3, 2014 at 11:51

Alex Barroso

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6 Comments

oliverbj Over a year ago

I tried to do this: if(!isset($_POST['maintenance'])) { $maintenance = 0; } .. still doesnt work.

Alex Barroso Over a year ago

Look at your loop, you are looping through $_POST and $_POST does not contain 'maintenance' key

oliverbj Over a year ago

I am not following. Sorry. Would you mind updating your answer, with your example?

Alex Barroso Over a year ago

Please try to understand what $_POST is and that you are doing a foreach on that variable and you don't have the 'maintenance' key there so it will never be modified on the database.

oliverbj Over a year ago

But I have other fields in my form, such as normal text inputs, and that works.

|

Tim · Accepted Answer · 2014-01-03 11:52:29Z

0

If an checkbox is unchecked it is not set in your $_POST. You have to check something like this:

if(isset($_POST['maintenance']) && $_POST['maintanance'] != 0) {
    //is checked
} else {
    //is unchecked
}

answered Jan 3, 2014 at 11:52

Tim

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2 Comments

Tim Over a year ago

@Alex-barroso beat me to it ;)

oliverbj Over a year ago

I tried this. If it was checked, I put hte $maintenance = 1 and if unchecked, $maintenance = 0. Didn't work..

Mohammad Faisal Islam · Accepted Answer · 2014-01-03 11:57:13Z

0

You can try this:

<?php

if($_SERVER['REQUEST_METHOD'] == 'GET') {
    if($sdata['maintenance']==1):
        $maintenance="checked='checked'";
    else:
        $maintenance="";
    endif;
}
elseif($_SERVER['REQUEST_METHOD'] == 'POST') {
    if(array_key_exists('maintenance',$_POST)) {
        $maintenance="checked='checked'";
    }
    else{
        $maintenance="";
    }
}

answered Jan 3, 2014 at 11:57

Mohammad Faisal Islam

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Comments

Elendai · Accepted Answer · 2014-01-03 12:09:11Z

0

Place the default (off) value in hidden input before checkbox:

<input type="hidden" name="maintenance" value="0"/>
<input type="checkbox" name="maintenance" value="1" <?=($sdata['maintenance']==1 ? 'checked' : '')?> >

answered Jan 3, 2014 at 12:09

Elendai

1

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