WORDPRESS: Widget base structure

widget_base.php

<?php

class YourClassName extends WP_Widget {

	public function YourClassName()
	{
		// Widget Options
		$widget_ops = array(
			'classname'   => 'yourclassname',
			'description' => 'Your description'
			);
		// Control Options
		$control_ops = array(
			'width'   => 250,
			'height'  => 350,
			'id_base' => 'yourclassname'
			);

		// Instance Widget
		$this->WP_Widget( 'yourclassname', 'Your Widget Name', $widget_ops, $control_ops );
	}




	/* The form for the backend configuration in the "Widget" Sector of the Wordpress backend
	============================================================================ */
	public function form( $instance )
	{
		// Set default arguments
		$defaults = array();

		// Merging args with defaults
		$instance = wp_parse_args( (array) $instance, $defaults );

		// Show the form - this is just an example
		?>

		<p>
			<label for="<?php echo $this->get_field_id( 'title' ); ?>">Title</label>
			<input type="text" name="<?php echo $this->get_field_name( 'title' ); ?>" value="<?php echo $instance['title']; ?>" id="<?php echo $this->get_field_id( 'title' ); ?>" class="widefat" />
		</p>

		<?php
	}




	/* Save the new configuration
	============================================================================ */
	public function update( $new_instance, $old_instance )
	{
		$instance = $old_instance;
		$instance['title'] = strip_tags( $new_instance['title']);
		// and so on…

		return $instance;
	}




	/* Display the widget
	============================================================================ */
	public function widget( $args, $instance )
	{
		extract($args);

		$title = apply_filters('widget_title', $instance['title']);

		// Start the widget output
		echo $before_widget;

		// Widget Title
		if( ! empty($title) ) { echo $before_title . $title . $after_title; }

		// Your widget-content goes here

		// Close the widget
		echo $after_widget;
	}

}

/* Register the new Widget
==================================== */
function load_your_widget() {
	register_widget( 'YourClassName' );
}

add_action( 'widgets_init', 'load_your_widget');

//End of file