As this article is somewhat older and perhaps even past it’s prime, please proceed with a sense of adventure and in a spirit of good cheer. There are some amazing ideas here but the code may need some tender love and care. Good luck!
I know you’ve been waiting patiently for this one. Everybody loves the Sidebar Template. But we’re going to do ours a little differently than everyone else.
Ours is going to be better.

Custom Sidebar Functions

First things first. With a WordPress Sidebar Template, we need to make sure it’s widgetized. Ours is going to have two widget areas. That way we can re-use this code for 2-column or 3-column themes (on a 2-column theme the sidebars are stacked, one on top of the other).
This is pretty straightforward. In our functions.php file we’re going to register our widget areas with the following code.

// Register widgetized areas
function theme_widgets_init() {
	// Area 1
	register_sidebar( array (
	'name' => 'Primary Widget Area',
	'id' => 'primary_widget_area',
	'before_widget' => '<li id="%1$s">',
	'after_widget' => "</li>",
	'before_title' => '<h3>',
	'after_title' => '</h3>',
  ) );
	// Area 2
	register_sidebar( array (
	'name' => 'Secondary Widget Area',
	'id' => 'secondary_widget_area',
	'before_widget' => '<li id="%1$s">',
	'after_widget' => "</li>",
	'before_title' => '<h3>',
	'after_title' => '</h3>',
  ) );
} // end theme_widgets_init
add_action( 'init', 'theme_widgets_init' );

Now we’ve got two widget areas: Primary Widget Area and Secondary Widget Area. There’s no point naming them Primary Sidebar or Secondary Sidebar. In some layouts they might not even be sidebars—but they’ll always be widget areas.
Now, still in functions.php we’re going to add two more super-cool custom code snippets.
Firstly, we’re going to pre-set our default widgets: The Search, Pages, Categories, Archives, Links and Meta Widgets. We won’t be coding them in manually to sidebar.php. We’ll be telling WordPress to add them to our dynamic widget area in the settings (thank Ptah Dunbar for this).

$preset_widgets = array (
	'primary_widget_area'  => array( 'search', 'pages', 'categories', 'archives' ),
	'secondary_widget_area'  => array( 'links', 'meta' )
);
if ( isset( $_GET['activated'] ) ) {
	update_option( 'sidebars_widgets', $preset_widgets );
}
// update_option( 'sidebars_widgets', NULL );

Now, in our Primary Widget Area (primary_widget_area) we’ve got the Search Widget, the Pages Widget, the Categories Widget, and the Archives Widget. The Secondary Widget Area (secondary_widget_area) has the Links and Meta Widgets. They’re all loaded up there in our WordPress options, ready and waiting.
Did you see // update_option( 'sidebars_widgets', NULL ); in the last line? Uncomment that line if you need to reset your widgets for any reason. As I’m sure you can guess, NULL means no widgets.
Now secondly, we’re going to create a new conditional that will check to see if there are any widgets in a given widget area. This will be incredibly useful (with props to Chaos Kaizer) when we code up our Sidebar Template.

// Check for static widgets in widget-ready areas
function is_sidebar_active( $index ){
  global $wp_registered_sidebars;
  $widgetcolums = wp_get_sidebars_widgets();
  if ($widgetcolums[$index]) return true;
	return false;
} // end is_sidebar_active

Now we need to put these custom code snippets to work.

Coding The Sidebar Template

With our dynamic widget areas registered and pre-set widgets, our Sidebar Template is going to be one of the simplest templates you’ll ever see. But remember, we’re also going to want to wrap our sidebars in an IF statement using our new conditional is_sidebar_active().
Here’s what it’ll look like:

<?php if ( is_sidebar_active('primary_widget_area') ) : ?>
		<div id="primary">
			<ul>
				<?php dynamic_sidebar('primary_widget_area'); ?>
			</ul>
		</div><!-- #primary .widget-area -->
<?php endif; ?>
<?php if ( is_sidebar_active('secondary_widget_area') ) : ?>
		<div id="secondary">
			<ul>
				<?php dynamic_sidebar('secondary_widget_area'); ?>
			</ul>
		</div><!-- #secondary .widget-area -->
<?php endif; ?>

Now if you go into the widget admin page and pull all those widgets out of any one of those widget areas the conditional statement guarding the markup will fail. Big time. And to our benefit. No widgets. No markup. Dead simple.
Just the way we like things around here.

How To Create a WordPress Theme

This post is part of a WordPress Themes Tutorial that will show you how to create a powerful WordPress Theme from scratch. Read it from the beginning and code yourself up something awesome.