This adds a simple custom-widget.php in your CHILD theme wp-content directory. Add the HTML code to the page you want your widget to appear: <form method='post' action="custom-widget.php"> <p class="submit"> <input type="submit" class="button-primary" value="submit" /> </p> </form>

/**
* Sets up the custom widget name etc
*/
public function __construct() {
 // widget actual processes
}

/**

Outputs the content of the custom widget
@param array $args
@param array $instance */ public function widget( $args, $instance ) { // outputs the content of the custom widget }

/**

Outputs the options form on admin
@param array $instance The custom widget options */ public function form( $instance ) { // outputs the options form on admin }

/**

Processing custom widget options on save
@param array $new_instance The new options
@param array $old_instance The previous options / public function update( $new_instance, $old_instance ) { // processes widget options to be saved } }
/ // Start by adding the following to your page where you want the widget to appear: //

// Create a new php file entitled custom-widget.php in your CHILD theme wp-content directory

Some background on this custom widget plugin and an example:

maxsherlock/Custom_WP_Widget_bypassing_functions.md