How to save meta checkbox Wordpress

Question

I want to save a meta with a checkbox for all my posts, here's my code :

add_action('save_post','save_metaboxes');
function save_metaboxes($post_ID){

if(isset($_POST['is_viewpay'])) {
    $old_meta = get_post_meta($post_ID, '_is_viewpay', true);

    if(!empty($old_meta)){
        update_post_meta($post_ID, '_is_viewpay', 'active');
    } else {
        update_post_meta($post_ID, '_is_viewpay', '');
    }
}

}

The problem is when I uncheck the checkbox and save my post, It always stay checked. I don't know why.

Thanks for your help !

Answer 1

You can use this to update your post meta

function save_metaboxes($post_ID){    
    if( isset($_POST['is_viewpay']) ){
        $featured = 1;            
    }
    else{
        $featured = 0;
    }
    update_post_meta( $post_id, '_is_viewpay',  $featured);
}

To make the checkbox checked, you can use something like this:

<?php $check = $featured ? 'checked':''; ?>
<input <?php echo $check; ?> name="is-viewcheck" type="checkbox" value="1"> Is view pay