echoz

This plugin provides functions to retrieve the parent category of any particular post should it be assigned to a sub category of that parent category.
Using this feature, the plugin is also able to modify the WordPress Loop to redirect any category page generation to the parent category. This is especially useful when theme developers want to be able to specify category-x.php templates and have all related posts, be it those assigned to the category or the sub categories use that template for page generation.
So for example the current category structure is as follows.
<ul>
<li>Main Category (has category-x.php template)
<ul>
<li>Sub Category 1</li>
<li>Sub Category 2</li>
</ul>
</li>
</ul>
A post is assigned to “Sub Category 2”.
When the post is requested the plugin will automatically detect if it has a parent category. If so, it will modify the WP variables to set the current category as the parent category and add a new variable stating the actual category of the post. This affects the WordPress Loop to category-x.php template defined for the parent
<h3>Usable Commands for Theme Developers</h3>
The PHP commands for theme developers to use are pretty straight forward.
get_category_child() returns the current post child category ID.
is_parent() checks if the current post is at the parent category.
get_category_title($id) gets the title of the category that is $id.
get_category_parent() returns the current post’s parent category ID.

Elevate Parent Category Template

Elevates parent category template to top of WordPress Loop.

Michael Torbert

Once activated, only posts from the current category are displayed in your loop (no posts from sub cats). 
That’s all it does. No options. If you find you need options, let me know and I’ll build them into it.
As of 0.4 I remove the filter after the main query is built so that it doesn’t interfere with widgets. 
If you have a custom query or call wp_query on a category archive template, you’ll need to add and remove the filters before and after your query. Below is an example of how to do this if you use wp_query. Again, this is not necessary unless you have modified queries in a template file.
<pre><code>add_filter( 'posts_where', 'ft_nscp_mod_where' );
query_posts( array( 'your-custom' => 'args' ) );
remove_filter( 'posts_where', 'ft_nscp_mod_where' );
</code></pre>
Its important that you remove what you add.

No Sub-Category Posts in Loops

Once activated, only posts from the current category are displayed in your loop (no posts from sub cats).

Elevate Parent Category Template vs No Sub-Category Posts in Loops