Add custom post types to the Loop by adding an action to pre_get_posts (doing it wrong)

gistfile1.aw

<?php

if ( ! function_exists( 'ucc_include_custom_post_types' ) ) {
function ucc_include_custom_post_types( $query ) {
	// Don't break admin or preview pages. This is also a good place to exclude feed with ! is_feed() if desired.
	if ( ! is_preview() && ! is_admin() && ! is_singular() ) {
		$args = array(
			'public' => true ,
			'_builtin' => false
		);
		$output = 'names';
		$operator = 'and';

		$post_types = get_post_types( $args, $output, $operator );

		// Add 'link' and/or 'page' to array() if you want these included.
		// array( 'post', 'link', 'page' ), etc.
		$post_types = array_merge( $post_types, array( 'post' ) );

		if ($query->is_feed) {
			// Do feed processing here if you did not exclude it previously. This if/else 
			// is not necessary if you want custom post types included in your feed.
		} else {
			$my_post_type = get_query_var( 'post_type' );
			if ( empty( $my_post_type ) )
				$query->set( 'post_type', $post_types );
		}
	}
} }
add_action( 'pre_get_posts', 'ucc_include_custom_post_types' );

/*
	Copyright 2012 Jennifer M. Dodd <jmdodd@gmail.com>
	Released under the GPLv2 (or later).
*/

?>