How to get tagged pages to show up with tagged posts?

Question

I'm trying to implement tags on my pages, so pages show up in the tag clouds I have printing in various places on the site.

The problem? If I tag a page, it doesn't show up in the list. Only posts do. I'm using the following in my functions.php to enable page tags:

// add tag support to pages
function tags_support_all() {
register_taxonomy_for_object_type('post_tag', 'page');
}

// ensure all tags are included in queries
function tags_support_query($wp_query) {
if ($wp_query->get('tag')) $wp_query->set('page_type', 'any');
}

// tag hooks
add_action('init', 'tags_support_all');
add_action('pre_get_posts', 'tags_support_query');

My tag.php page has the following:

<?php while (have_posts()) : the_post(); ?>

<h2 class="category-title" id="post-<?php the_ID(); ?>"><a href="<?php the_permalink() ?    >" rel="bookmark" title="Permanent Link to <?php the_title(); ?>" style="color:#000;"><?php     the_title(); ?></a></h2>
 <?php the_excerpt(); ?>

<?php if ($wp_query->max_num_pages > 15) : ?>
 <nav class="post-nav">
<ul class="pager">
  <li class="previous"><?php next_posts_link(__('&larr; Older posts', 'roots')); ?>      </li>
  <li class="next"><?php previous_posts_link(__('Newer posts &rarr;', 'roots')); ?>   </li>
</ul>

Answer 1

You need to use pre_get_posts hook. Paste this code to your themes functions.php file.

add_action('pre_get_posts', 'wpse_pre_get_posts');
function wpse_pre_get_posts($q)
{
    if( $q->is_main_query() && $q->is_tag() )
    {
        $q->set('post_type', array('post','page') );
    }
}