Framework for adding taxonomy filter and column to WordPress manage post admin pages.

Post_Taxonomy_Columns_And_Filter

<?php

class Post_Taxonomy_Columns_And_Filter {
	
	/**
	 * Constructor
	 */
	function Post_Taxonomy_Columns_And_Filter() {
		add_filter( 'manage_edit-mycustomposttype_columns', array( $this, 'manage_mycustomposttype_columns' ) );
		add_action( 'manage_mycustomposttype_posts_custom_column', array( $this, 'show_mycustomposttype_columns' ) );
		add_action( 'restrict_manage_posts', array( $this, 'admin_posts_tax_filter_menu' ) );
		add_filter( 'request', array( $this, 'admin_posts_tax_filter_query' ) );
	}

	/**
	 * Add a collection filter menu to the custom post type overview admin page
	 */
	function admin_posts_tax_filter_menu() {
		global $typenow, $wp_query;
		if ( $typenow == 'mycustomposttype' ) {
			$taxonomy = 'mycustomtaxonomy';
			$category_taxonomy = get_taxonomy( $taxonomy );
			$category_term = get_term_by( 'slug', $wp_query->query['mycustomtaxonomy'], $taxonomy );
			wp_dropdown_categories(array(
				'show_option_all' =>  __( "Show All {$category_taxonomy->label}" ),
				'taxonomy'        =>  $taxonomy,
				'name'            =>  $taxonomy,
				'orderby'         =>  'name',
				'selected'        =>  $category_term->term_id,
				'hierarchical'    =>  true,
				'depth'           =>  3,
				'show_count'      =>  true, // Show # listings in parens
				'hide_empty'      =>  false, // Don't show businesses w/o listings
			));
		}
	}

	/**
	 * Filter custom post type overview admin page based on collection menu
	 */
	function admin_posts_tax_filter_query( $request ) {
		global $typenow;
		if ( is_admin() && $typenow == 'mycustomposttype' ) {
			$term = get_term( $request['mycustomtaxonomy'], 'mycustomtaxonomy');
			$request['mycustomtaxonomy'] = $term->slug;
		}
		return $request;
	}
	
	/**
	 * Add custom taxonomy column to manage custom post type page
	 */
	function manage_mycustomposttype_columns( $columns ) {
		$new_columns = array();
		foreach ( $columns as $key => $val ) {
			if ( $key == 'date' )
				$new_columns['mycustomtaxonomy_col'] = __( 'My Custom Taxonomy' );
			$new_columns[$key] = $val;
		}
		return $new_columns;
	}
	
	/**
	 * Show custom taxonomy column on manage custom post type page
	 */
	function show_mycustomposttype_columns( $name ) {
		global $post;
		switch ( $name ) {
			case 'mycustomtaxonomy_col':
				echo get_the_term_list( $post->ID, 'mycustomtaxonomy', '', ', ', '' );
				break;
		}
	}
	
}

?>