Chapter 7 135 wp_tag_cloud(array( 'number'=>3, 'unit'=>'', 'format'=>'list', 'orderby'=>'count', 'order'=>'DESC', 'taxonomy'=>$tax )); } ?> </div> </div> <?php get_sidebar(); ?> <?php get_footer(); ?> You can now use your Taxonomies page template. Go and create a new page in the WordPress administrative area, and make sure that it uses the Taxonomies page template. If you need more information on how to do this, see the recipe Creating a simple page template. Visit your newly-created page. You should see output similar to the example shown in the following screenshot: Custom Page Templates 136 How it works By this time, you should have a pretty good idea of the way in which custom page templates work. If you need a refresher, see the How it works section of the Creating a simple page template recipe. Here you're taking advantage of the taxonomy system that has been built into WordPress since Version 2.3, as well as the custom taxonomy capabilities built into WordPress since Version 2.8. The taxonomy system essentially lets you classify objects in your system in ways that makes sense for your particular content. If you're reviewing movies, it makes sense to classify them in Genres. If you're looking at art, it makes sense to classify them by Periods. After you've classied your content, you need to somehow let visitors navigate according to your custom taxonomies. That is where this recipe comes into play. In this recipe, you use a couple of new functions. First, you take advantage of the get_object_taxonomies function. This function takes a single parameter that indicates the type of object that you want to retrieve taxonomies for, and returns an array of registered taxonomy names for that object type. Next, you iterate over each taxonomy name, retrieve the appropriate taxonomy object, and then display the taxonomy label, and a list of all items in that taxonomy that have been used to classify objects. The function that you use to display the items in taxonomy is wp_tag_cloud. Most people don't realize the full potential of this function, believing that it is only used for displaying post tags. However, you can use wp_tag_cloud to display items from any taxonomy, by passing a taxonomy name in as a parameter. You pass other parameters as well, and it is important to know why you provide the values that you do: number—used to limit the number of taxonomy items present in the list output unit—setting this parameter to an empty string ensures that all items are the same size format—setting this parameter to the value list causes the output to be an unordered list orderby—you can use different values here, but using count ensures that your taxonomy items are sorted by the number of objects they are assigned to order—setting this to DESC makes the taxonomy items order themselves from high to low taxonomy—the value here determines which object classication will be looked at inside of the function Internal to wp_tag_cloud is a complicated SQL query that looks at different taxonomy tables and the posts table, applies the options that you pass, and generates the appropriate output. An investigation into the internals of this function is beyond the scope of this book.       Chapter 7 137 See also Creating an archives page template Creating a simple page template Displaying author avatars and descriptions Multi-author blogs are gaining momentum in the professional and business blogging world. As such, if you're producing a business theme for WordPress, you might want to take special care to produce a page template that displays information about each of the authors on a blog. In this recipe, you'll create such as page template. This will show the author's display name, avatar, biography, and the number of posts that they've written for the site. It will also contain a link to that author's posts. Getting ready To properly use the techniques in this recipe, you'll need to be working with a theme that you previously acquired or developed. If you haven't started developing a custom theme yet, I recommend using the Thematic theme. It can be freely downloaded from the WordPress.org Theme Repository at http://wordpress.org/extend/themes/thematic/. How to do it First, follow the steps in the recipe Creating a simple page template until you reach the point at which you start adding custom content. While following that recipe, modify the lename from hello-world-page-template.php to authors-page-template.php, and change the value of the Template Name: header from Hello World to Authors. Now you're ready to start adding the appropriate content. After the page template comment header, add the following markup to your page template, and then save the le: <?php get_header(); ?> <div id="container"> <div id="content"> <?php $authors = get_users_of_blog(); foreach($authors as $author) { $num_posts = get_usernumposts($author->ID); if($num_posts>0) { $id = $author->ID; $author = new WP_User($id); ?>   Custom Page Templates 138 <div class="author" id="author-<?php echo $id; ?>"> <h2 class="author-name"> <?php the_author_meta('display_name',$id); ?> </h2> <div class="author-gravatar"> <?php echo get_avatar($id); ?> </div> <div class="author-description"> <?php the_author_meta('description',$id); ?> </div> <div class="author-posts-link"> <a href="<?php echo get_author_posts_url($id); ?>"> <?php printf( '%s has written %d posts. Check \'em out!', get_the_author_meta('display_name'), $num_posts ); ?> </a> </div> </div> <?php } } ?> </div> </div> <?php get_sidebar(); ?> <?php get_footer(); ?> You can now use your Authors page template. Go and create a new page in the WordPress administrative area, and make sure that it uses the Authors page template. If you need more information on how to do this, see the recipe Creating a simple page template. Visit your newly-created page. You should see output similar to the following, depending on the authors that you have on your site: Chapter 7 139 In the above screenshot, you see numerous authors with their name, description, avatar, and a link to their posts. The information could be expanded upon, but this is a good starting point. How it works By this point you should have a pretty good idea of the way that custom page templates work. If you need a refresher, see the How it works section of the Creating a simple page template recipe. There are a few functions of note in this recipe, nearly all of them dealing with the retrieval of author data. The code listing starts with the get_users_of_blog function. This function returns an array of user objects, one for each user currently in the system. Next, you iterate over the array of users, checking to see whether they have published any posts or not. If an author has published at least one post, then you proceed with displaying various user data. Custom Page Templates 140 Here, user data is displayed by using the the_author_meta function with different parameters and the value of the user ID for the author currently being iterated over. In addition, the get_ avatar function is used to display the appropriate image for each author. All of the data for each author is wrapped in a nice set of HTML tags that provide proper formatting and display. There's more If you're going to display information for each author on a dedicated page, you should probably redisplay that information on their individual author listings as well. You already have the proper markup, so this will be a piece of cake. First, separate out the display code for an author into its own le. You could call this le something like author-expanded.php. It will contain the following code: <div class="author" id="author-<?php echo $id; ?>"> <h2 class="author-name"> <?php the_author_meta('display_name',$id); ?> </h2> <div class="author-gravatar"> <?php echo get_avatar($id); ?> </div> <div class="author-description"> <?php the_author_meta('description',$id); ?> </div> <div class="author-posts-link"> <a href="<?php echo get_author_posts_url($id); ?>"> <?php printf( '%s has written %d posts. Check \'em out!', get_the_author_meta('display_name',$id), $num_posts ); ?> </a> </div> </div> Chapter 7 141 Now go back to your authors-page-template.php, and change it to use the newly-created le, leaving you with something like the following: <div id="container"> <div id="content"> <?php $authors = get_users_of_blog(); foreach($authors as $author) { $num_posts = get_usernumposts($author->ID); if($num_posts>0) { $id = $author->ID; $author = new WP_User($id); include(STYLESHEETPATH.'/author-expanded.php'); } } ?> </div> </div> After that, open up your theme's author.php le (if you don't have one, just create one and copy the contents of index.php into the new le). Immediately before the posts listing, insert a call for the expanded author information. Your code should look something like the following example: <?php global $wp_query; $id = $wp_query->get_queried_object_id(); $author = new WP_User($id); $num_posts = get_usernumposts($id); include(STYLESHEETPATH.'/author-expanded.php'); if(have_posts()) { while(have_posts()) { the_post(); Custom Page Templates 142 Call up an author's post page, and you'll see the expanded author information, followed by a list of that user's posts: See also Creating a simple page template Creating a table of contents page template Let's say you're writing a book where you publish each chapter as it is nished. You're going to use WordPress pages for your content organization, with a top-level page describing the book and then a subpage for each of the chapters in your book. On the top-level page, in addition to the book title and description, you want to display links to each of the chapters, and a brief description of their content. This task would be difcult with a lot of other content management systems, but not with WordPress.  Chapter 7 143 Getting ready To properly use the techniques in this recipe, you'll need to be working with a theme that you previously acquired or developed. If you haven't started developing a custom theme yet, I recommend using the Thematic theme. It can be freely downloaded from the WordPress.org Theme Repository, at http://wordpress.org/extend/themes/thematic/. How to do it First, follow the steps in the recipe Creating a simple page template until you reach the point at which you start adding custom content. While following that recipe, modify the lename from hello-world-page-template.php to toc-page-template.php and change the value of the Template Name: header from Hello World to Table of Contents. Now you need to create the appropriate content that will be displayed when using this page template. Create a top-level page for your book with the work's title as the post title, and choose the Table of Contents template from the Template drop-down menu in the Attributes meta box. Then create several child pages, using the chapter's title as the post title. For each child page, make sure that you choose your main book page from the Parent dropdown and the Table of Contents option from the Template dropdown. When you're done, visit the Edit Pages interface, and you should see something like the example shown in the following screenshot: Custom Page Templates 144 Chapter order When you're creating your book's chapters, make sure that you set the Order property in the Attributes meta box (the same place that you change the page template) to the number of the chapter. This ensures that your chapters appear in the correct order. Now you're ready to write the code to generate your table of contents. After the comment header, add the following markup to your page template, and then save the le: <?php get_header(); ?> <div id="container"> <div id="content"> <?php if(have_posts()) { while(have_posts()) { the_post(); ?> <h2 class="book-title"><?php the_title(); ?></h2> <div class="book-description"> <?php the_content(); ?> </div> <h2>Chapters</h2> <ol> <?php $chapters_query = new WP_Query(array( 'post_type'=>'page', 'post_parent'=>get_the_ID(), 'orderby'=>'menu_order', 'order'=>'ASC' )); if($chapters_query->have_posts()) { while($chapters_query->have_posts()) { $chapters_query->the_post(); ?> <li class="chapter"> <h3 class="chapter-title"> <a href="<?php the_permalink(); ?>"> <?php the_title(); ?> </a> </h3> <?php the_excerpt(); ?> </li> <?php . recommend using the Thematic theme. It can be freely downloaded from the WordPress. org Theme Repository at http:/ /wordpress. org/extend /themes/ thematic/. How to do it First, follow the steps in the recipe. using the Thematic theme. It can be freely downloaded from the WordPress. org Theme Repository, at http:/ /wordpress. org/extend /themes/ thematic/. How to do it First, follow the steps in the recipe. task would be difcult with a lot of other content management systems, but not with WordPress.  Chapter 7 143 Getting ready To properly use the techniques in this recipe, you'll need to