Saving widget options from class method

Question

I have a widget class (derived from WP_Widget) that has a method (called via ajax) to update part of its options(the elements order) without the user to click "Save", to set the handler I do from the constructor:

add_action('wp_ajax_bgw_update_order', array(&$this, 'update_order'));

The update_order method does something similar to this question but it does not save the new options. My code:

public function update_order() {
    if (!is_admin()) die('Not an admin');
    if (!isset($_REQUEST['nonce']) ||
        !wp_verify_nonce($_REQUEST['nonce'], 'section-order-nonce')) 
        die('Invalid Nonce');
    $sections = $this->sections;
    $new_order = $_POST['section'];
    $new_sections = array();

    foreach($new_order as $v) {
        if (isset($sections[$v])) {
            $new_sections[$v] = $sections[$v];
        }
    }
    $this->sections = $new_sections;
    $settings = $this->get_settings();
    $settings[$this->number]['sections_order'] = $new_sections;
    $this->save_settings($settings);
    print_r($this->get_settings());
    die();
}

My update function does the usual stuff:

public function update( $new_instance, $old_instance ) {
    $instance = array();
    $instance['username'] = strip_tags($new_instance['username']);
    $instance['count'] = strip_tags($new_instance['count']);
    // [...]
    return $instance;
}

When I log $settings from update_order it has the right value:

Array
(
    [3] => Array
        (
            [username] => username
            [count] => 0
            [title] => GitHub
            [skip_forks] => 1
            [show_octocat] => 1
            [sections_order] => Array
                (
                    [1] => Activity
                    [0] => Repositories
                )

        )

)

The update method doesn't get called and when I hit the "Save" button $instance (logged from the form method) doesn't have a sections_order key.

I come to the conclusion that save_settings doesn't do what I think it does.

How can I save the options from the update_order method? What I'm trying to achieve is to save sections_order without the user to click the "Save" button.

Answer 1

Why are you writing your own save handlers for widgets? The update method your widget class will take care of this. You're saving per widget settings, exactly what the Widget API was designed to do.

<?php
class WPSE76224_Widget extends WP_Widget
{
    public function __construct()
    {
        // Create the widget options and such here, then call
        // $this->WP_Widget to let wordpress know about it.
    }

    public function widget($args, $instance)
    {
        // display the widget on the front end.
    }

    public function form($instance)
    {
        // The widget form in the admin area.
    }

    public function update($new, $old)
    {
        // Saves your data, called via AJAX. But your saving logic here.
    }
}

Since WordPress "loads" the widget class (you just register it with register_widget). Chances are an instance of of the widget class is not created when you think it is -- on ajax requests, for instance. If you do want to write your ajax handlers, you'll likely have to move that functionality outside of the widget class.

Further reading:

1. http://codex.wordpress.org/Widgets_API
2. http://pmg.co/how-to-build-your-own-wordpress-widgets This is an older tutorial I wrote. The "fetching the tweet" part doesn't work anymore due to changes a Twitter.