In my personal opinion, I believe in modular functional code based on a framework created by do_action(). You’re right in that the way my code was written in that post is not the best representation. And it is true that if you have do_action() followed by add_action() the add_action() will not be executed. Here’s what typically happens in WordPress. Take a home.php example. Here’s an example of a home.php using hooks.

<?php get_header();
do_action( 'wps_home_before_banner' ); ?>
<div id="banner">
	<?php do_action( 'wps_banner' ); ?>
</div><!-- end #banner -->
<div class="banner-shadow"></div>

<?php
do_action( 'wps_home_before' ); ?>
<div id="content-sidebar-wrap">
	<div id="content">
	<?php do_action( 'wps_content' ); ?>
	</div>
	<?php get_sidebar(); ?>
</div>

<?php do_action( 'genesis_home_after' );

get_footer();

So in this code, I’ve hardcoded a frame with some hooks to write modular code. While I still do not believe this to be the best method, it is how more and more themes are operating. As you can see I have no add_action() statements here. In other files (e.g., functions.php, other theme files, a plugin, etc.) I would have the functions that hook into this to create the home page. So consider a home-functions.php that looks something like this:

<?php
add_action( 'wps_banner', 'wps_do_banner' );
/**
 * Outputs widgeted slider area
 */
function wps_do_banner() {
?>
	<div class="slider">
		<?php if ( ! dynamic_sidebar('home-slider' ) ) : ?>
		<div class="widget">
			<h3><?php _e( 'Home Slider', 'genesis' ); ?></h3>
			<p><?php _e( 'Designed for a Slider', 'genesis' ); ?></p>
		</div>
		<?php endif; ?>
	</div><!-- end .slider -->
<?php
}

add_action( 'wps_banner', 'wps_do_search' );
/**
 * Outputs widgeted search area
 */
function wps_do_search() {
?>
	<div class="home-search">
		<h3><?php _e( 'Homes for Sale' , 'genesis' ); ?></h3>
		<?php if ( !dynamic_sidebar( 'home-search' ) ) : ?>
		<div class="widget">
			<h3><?php _e('Home Search Area' , 'genesis' ); ?></h3>
			<p><?php _e('Designed for the MLS Home Search Widget' , 'genesis' ); ?></p>
		</div>
		<?php endif; ?>
	</div><!-- end .home-search -->
<?php
}

add_action( 'wps_banner', 'wps_clear' );
/**
 * Outputs clearfix
 */
function wps_clear() {
	echo '<div class="clear"></div>';
}

add_action( 'wps_banner', 'wps_banner_bottom' );
/**
 * Outputs widgeted call of actions area
 */
function wps_banner_bottom() {
?>
	<?php if ( is_active_sidebar( 'banner-bottom' ) ) : ?>
	<div class="bottom-widget">
		<div class="wrap">
		<?php if ( ! dynamic_sidebar( 'banner-bottom' ) ) : ?>
		<div class="widget">
			<h3><?php _e('Widget Area', 'genesis' ); ?></h3>
			<p><?php _e('Designed for Call of Actions or Featured Listings', 'genesis' ); ?></p>
		</div>
		<?php endif; ?>

		</div><!-- end .wrap -->
	</div><!-- end .bottom-widget -->

	<?php
	endif;
}

add_action( 'wps_content', 'wps_do_feature_content' );
/**
 * Outputs widgeted feature content area
 */
function wps_do_feature_content() {
?>
	<?php if ( ! dynamic_sidebar( 'Home' ) ) : ?>
	<div class="widget">
		<h3><?php _e( 'Widget Area' , 'genesis' ); ?></h3>
		<p><?php _e( 'Designed for Call of Actions or Featured Listings', 'genesis' ); ?></p>
	</div>
	<?php endif; ?>
}

Now in a framework like Genesis, this becomes much simpler because these hooks pre-exist inside the genesis() function call, so hardcoding a home.php file is not necessary. So the home.php file would look more like the second part of modular function code than anything. So…

<?php 

// Remove Breadcrumbs
remove_action('genesis_before_loop', 'genesis_do_breadcrumbs');

// Add Banner
add_action( 'genesis_after_header', 'wps_do_banner' );
//previous code

// Add Search widget
add_action( 'genesis_after_header', 'wps_do_search' );
//previous code

add_action( 'genesis_after_header', 'wps_clear' );
//previous code

add_action( 'genesis_after_header', 'wps_banner_bottom' );
//previous code

// Add Optional Features Area
add_action( 'genesis_before_loop', 'wps_do_feature_content' );
//previous code

genesis();

Even using genesis(); I am calling all the add_actions prior to the execution of the do_actions. Does this clarify a bit more?

It must be that these methods are being described from a conceptual point of view rather than from a concrete point of view. Conceptually when a programmer uses do_action he is creating a hook that other programmers can use to actions into his function, but that is what the programmer is doing; it is not the do_action method creating the hook. The method rather is executing (or doing) an action if an action exists for it to do.

If any method is creating a hook, then the hook is being created by add_action, not do_action, because in order for do_action to do anything useful, at least one add_action must have been called for the hook that do_action will use to execute the action.

The confusion that comes from describing do_action as creating a hook can be illustrated by some of your code. At the bottom of your post you have code that calls “do_action( ‘my_action’ ),” then “add_filter( ‘my_action’ , ‘my_function’)” to illustrate that PHP is forgiving and that filters can be used like actions. But in your code because add_filter follows do_action, add_filter does not impact the behavior of do_action. Even it if were changed to add_action it would have no impact. Before do_action can have any impact add_action needs to be called first to give do_action something to “do.”

Isn’t this right?

global $post;
if ( 'listing' == $post->post_type ) {
    //execute code
}

This is up to the style of your theme, and is not part of the code.

Thanks,

Which direction did you take this? You can also see Viper’s plugin: Add Descendants As Submenu Items.

Please see the plugin author for this.