Marketpress List Products Function

function simplemarket_list_products( $echo = true, $paginate = '', $page = '', $per_page = '', $order_by = '', $order = '', $category = '', $tag = '' ) {
  global $wp_query, $mp;
  $settings = get_option('mp_settings');

  //setup taxonomy if applicable
  if ($category) {
    $taxonomy_query = '&product_category=' . sanitize_title($category);
  } else if ($tag) {
    $taxonomy_query = '&product_tag=' . sanitize_title($tag);
  } else if ($wp_query->query_vars['taxonomy'] == 'product_category' || $wp_query->query_vars['taxonomy'] == 'product_tag') {
    $taxonomy_query = '&' . $wp_query->query_vars['taxonomy'] . '=' . get_query_var($wp_query->query_vars['taxonomy']);
  }

  //setup pagination
  $paged = false;
  if ($paginate) {
    $paged = true;
  } else if ($paginate === '') {
    if ($settings['paginate'])
      $paged = true;
    else
      $paginate_query = '&nopaging=true';
  } else {
    $paginate_query = '&nopaging=true';
  }

  //get page details
  if ($paged) {
    //figure out perpage
    if (intval($per_page)) {
      $paginate_query = '&posts_per_page='.intval($per_page);
    } else {
      $paginate_query = '&posts_per_page='.$settings['per_page'];
		}

    //figure out page
    if ($wp_query->query_vars['paged'])
      $paginate_query .= '&paged='.intval($wp_query->query_vars['paged']);

    if (intval($page))
      $paginate_query .= '&paged='.intval($page);
    else if ($wp_query->query_vars['paged'])
      $paginate_query .= '&paged='.intval($wp_query->query_vars['paged']);
  }

  //get order by
  if (!$order_by) {
    if ($settings['order_by'] == 'price')
      $order_by_query = '&meta_key=mp_price_sort&orderby=meta_value_num';
    else if ($settings['order_by'] == 'sales')
      $order_by_query = '&meta_key=mp_sales_count&orderby=meta_value_num';
    else
      $order_by_query = '&orderby='.$settings['order_by'];
  } else {
  	if ('price' == $order_by)
  		$order_by_query = '&meta_key=mp_price_sort&orderby=meta_value_num';
    else
    	$order_by_query = '&orderby='.$order_by;
  }

  //get order direction
  if (!$order) {
    $order_query = '&order='.$settings['order'];
  } else {
    $order_query = '&order='.$order;
  }

  //The Query
  $custom_query = new WP_Query('post_type=product&post_status=publish' . $taxonomy_query . $paginate_query . $order_by_query . $order_query);

  //allows pagination links to work get_posts_nav_link()
  if ($wp_query->max_num_pages == 0 || $taxonomy_query)
    $wp_query->max_num_pages = $custom_query->max_num_pages;

  $content = '<div id="mp_product_list">';

  if ($last = count($custom_query->posts)) {
    $count = 1;
    foreach ($custom_query->posts as $post) {

			//add last css class for styling grids
			if ($count == $last)
			  $class = array('mp_product', 'last-product');
			else
			  $class = 'mp_product';

      $content .= '<div '.mp_product_class(false, $class, $post->ID).'>';
      $content .= '<h3 class="mp_product_name"><a href="' . get_permalink( $post->ID ) . '">' . $post->post_title . '</a></h3>';
      $content .= '<div class="mp_product_content">';
      $product_content = mp_product_image( false, 'list', $post->ID );
      $product_content .= $mp->product_excerpt($post->post_excerpt, $post->post_content, $post->ID);
      $content .= apply_filters( 'mp_product_list_content', $product_content, $post->ID );
      $content .= '</div>';

      $content .= '<div class="mp_product_meta">';
      //price
      $meta = mp_product_price($post->ID);
      //button
      $meta .= mp_buy_button(false, 'list', $post->ID);
      $content .= apply_filters( 'mp_product_list_meta', $meta, $post->ID );
      $content .= '</div>';

      $content .= '</div>';

      $count++;
    }
  } else {
    $content .= '<div id="mp_no_products">' . apply_filters( 'mp_product_list_none', __('No Products', 'mp') ) . '</div>';
  }

  $content .= '</div>';

  if ($echo)
    echo $content;
  else
    return $content;
}