Array of checkboxes not saving in WordPress widget - wordpress

Question

This is my code for the widget:
function form( $instance ) {
$instance = wp_parse_args( (array)$instance, array(
'checkboxes' => array(
'Monday' => array('name' => 'Monday', 'value' => 'Monday', 'checked' => 1),
'Tuesday' => array('name' => 'Tuesday', 'value' => 'Tuesday', 'checked' => ''),
'Wednesday' => array('name' => 'Wednesday', 'value' => 'Wednesday', 'checked' => ''),
'Thursday' => array('name' => 'Thursday', 'value' => 'Thursday', 'checked' => ''),
'Friday' => array('name' => 'Friday', 'value' => 'Friday', 'checked' => ''),
'Saturday' => array('name' => 'Saturday', 'value' => 'Saturday', 'checked' => ''),
'Sunday' => array('name' => 'Sunday', 'value' => 'Sunday', 'checked' => '')
),
'title' => 'Workdays'
));
include( plugin_dir_path(__FILE__) . '/views/admin.php' );
}
function update( $new_instance, $old_instance ) {
$instance = $old_instance;
$instance['checkboxes'] = strip_tags($new_instance['checkboxes']);
return $instance;
}
This is the code for the view:
<div class='ws-business-info'>
<div class='form-group'>
<?php foreach($instance['checkboxes'] as $day ) : ?>
<div class='checkbox'>
<label>
<input type="checkbox"
name="<?php echo $day['name']; ?>"
class="form-control"
id="<?php echo $this->get_field_id($day['name']); ?>"
value="<?php echo $day['value']; ?>"
<?php checked('1', $day['checked']); ?>/>
<?php echo $day['name']; ?>
</label>
</div>
<?php endforeach; ?>
</div>
The widget displays the checkboxes as expected but the state will not save. Dumping the $old_instance variable in the update function gives a null value.

Answer 1

In the view file you defined input's id corectly, but you did not the same with name attribute.
Define the name attribute like this:
<input type="checkbox"
name="<?php echo $this->get_field_name( 'checkboxes' ), '[', esc_attr( $day['name'] ), ']'; ?>"
class="form-control"
id="<?php echo $this->get_field_id($day['name']); ?>"
value="<?php echo $day['value']; ?>"
<?php checked('1', $day['checked']); ?>/>
<?php echo $day['name']; ?>

Answer 2

public function widget( $args, $instance ) {
// outputs the content of the widget
}
This function has to be added along with the default constructor. Else the widget will not work.

Answer 3

Not exactly what you are looking for but this is how I saved a checkbox in metabox, you may get some hint from this...
Code used to display html
function html_rtsocial_metabox()
{
global $post;
$custom = get_post_custom($post->ID);
$suppress = $custom['_suppress_rtsocial'][0];
$checked = ($suppress=='yes')?'checked':'';
$value = ($suppress=='yes')?'yes':'no';
$html = '<br><input type="checkbox" name="_suppress_rtsocial" value="'.$value.'" '.$checked.' id="_suppress_rtsocial" /> Hide Social Icons ???';
$html .= '<br/><br/>';
echo $html;
}
While saving
update_post_meta($post_id,'_suppress_rtsocial',$_POST['_suppress_rtsocial']);
Added js for admin interface
function checkbox_helper(){
var ele =jQuery('#_suppress_rtsocial'),value;
ele.click(function(){
value = ele.is(':checked')?'yes':'no';
ele.val(value);
}
);
}