gistfile1.txt

<?php
/*
Plugin Name: Taxononmy Navigation Dropdown
Version: 0.1
Plugin URI: http://anthonycole.me/wordpress/taxonomy-nav-dropdown/
Description: This plugin allows you to add a simple widget linking all of your taxonomies together. 
Author: Anthony Cole
Author URI: http://anthonycole.me/

Copyright 2010 Anthony Cole  ( email: anthony@radiopicture.com.au )

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/


class Taxonomy_Widget extends WP_Widget {

	function Taxonomy_Widget() {
		$widget_ops = array( 'classname' => 'tnd-widget', 'description' => 'Allows you to add a taxonomy dropdown navigation to the frontend of your website' );
		$control_ops = array( 'width' => 200, 'height' => 250, 'id_base' => '' );
		$this->WP_Widget( 'Taxononmy_Nav', 'Taxonomy Nav', $widget_ops, $control_ops );
		
		
		add_action('wp_head', array($this, 'do_javascript') );
	}
	

	function widget( $args, $instance ) {
		extract( $args );
		echo $before_widget;
		$title = apply_filters('widget_title', $instance['title'] );
		if ( $title ) {
			echo $before_title . $title . $after_title;
		}
		
		$terms = get_terms(array($instance['taxonomy']));
		
		?>
		<select name="<?php echo $instance['taxonomy']; ?>" class="taxonomy-widget-select">
		<?php
		foreach( $terms as $terms ) : 
		?>
			<option value="<?php echo get_term_link( $term->slug, $instance['taxonomy'] ); ?>"><?php echo $term->name; ?></option>	
		<?php
		endforeach;
		?>
		</select>
		<?php
		echo $after_widget;
	}

	function update( $new_instance, $old_instance ) {
		$instance = $old_instance;
		
		foreach ( array('taxonomy') as $val ) {
			$instance[$val] = strip_tags( $new_instance[$val] );
		}
		
		return $instance;
	}

	function form( $instance ) {
		$defaults = array( 
			'taxonomy' => '', 
		);
		
		$taxonomies = array(
		'_builtin' => false,
		'public' => true,
		);
		
		$instance = wp_parse_args( (array) $instance, $defaults ); ?>
		<p>
			
			<label for="<?php echo $this->get_field_id( 'taxonomy' ); ?>"><?php _e("Taxonomy"); ?>:</label>
			<select id="<?php echo $this->get_field_id( 'taxonomy' ); ?>" name="<?php echo $this->get_field_name( 'taxonomy' ); ?>">
			<?php
			
			$args = array(
				'_builtin' => false,
			);

			$taxonomies = get_taxonomies($args, 'object');
				
			foreach($taxonomies as $taxonomy) {
				?> 
				<option <?php selected($instance['taxonomy'], $taxonomy->name); ?> value="<?php echo $taxonomy->slug; ?>"><?php echo $taxonomy->labels->name; ?></option>
				<?php
			}

			?>
			</select>
		</p>
	<?php 
	}
	
	function do_javascript() {
		?>
		<script type="text/javascript">
		jQuery(".taxonomy-widget-select").change(function(){
			var newurl = $("parent option:selected").attr("value");
			window.location.href = newurl;

		});
		</script>
		<?php
	}
}

function tnd_widget_func() {
	register_widget( 'Taxonomy_Widget' );
}

add_action( 'widgets_init', 'tnd_widget_func' );