Introduce new get_generic_template() function for themes to use to bring in pieces of template.

Use in twentyten for loop.php including. See #9015.

git-svn-id: http://svn.automattic.com/wordpress/trunk@13146 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-content/themes/twentyten/archive.php

@@ -17,7 +17,7 @@
 
 <?php rewind_posts(); ?>
 
-<?php include 'loop.php'; ?>
+<?php get_generic_template( 'loop', 'archive' ); ?>
 
 			</div><!-- #content -->
 		</div><!-- #container -->

wp-content/themes/twentyten/author.php

@@ -21,7 +21,7 @@
 
 <?php rewind_posts(); ?>
 
-<?php include 'loop.php'; ?>
+<?php get_generic_template( 'loop', 'author' ); ?>
 
 			</div><!-- #content -->
 		</div><!-- #container -->

wp-content/themes/twentyten/category.php

@@ -10,7 +10,7 @@
 
 <?php rewind_posts(); ?>
 
-<?php include 'loop.php'; ?>
+<?php get_generic_template( 'loop', 'category' ); ?>
 
 			</div><!-- #content -->
 		</div><!-- #container -->

wp-content/themes/twentyten/index.php

@@ -4,7 +4,7 @@
 			<div id="content">
 
     <?php if ( have_posts() ) : 
-		include 'loop.php';
+		get_generic_template( 'loop', 'index' );
     else : ?>
 		<h2><?php _e( 'Not Found', 'twentyten' ); ?></h2>
 		<div class="entry-content">

wp-content/themes/twentyten/search.php

@@ -5,7 +5,7 @@
 
 <?php if ( have_posts() ) : ?>
 				<h1 class="page-title"><?php _e( 'Search Results for: ', 'twentyten' ); ?><span><?php the_search_query(); ?></span></h1>
-	<?php include 'loop.php'; ?>
+	<?php get_generic_template( 'loop', 'search' ); ?>
 <?php else : ?>
 				<div id="post-0" class="post no-results not-found">
 					<h2 class="entry-title"><?php _e( 'Nothing Found', 'twentyten' ); ?></h2>

wp-content/themes/twentyten/tag.php

@@ -9,7 +9,7 @@
 
 <?php rewind_posts(); ?>
 
-<?php include 'loop.php'; ?>
+<?php get_generic_template( 'loop', 'tag' ); ?>
 
 			</div><!-- #content -->
 		</div><!-- #container -->

wp-includes/general-template.php

@@ -93,6 +93,35 @@ function get_sidebar( $name = null ) {
 		load_template( get_theme_root() . '/default/sidebar.php');
 }
 
+/**
+ * Load a generic template.
+ *
+ * Includes the named template for a theme or if a name is specified then a
+ * specialised template will be included. If the theme contains no {slug}.php file
+ * then no template will be included.
+ *
+ * For the parameter, if the file is called "{slug}-special.php" then specify
+ * "special".
+ *
+ * @uses locate_template()
+ * @since 3.0.0
+ * @uses do_action() Calls 'get_generic_template_{$slug}' action.
+ *
+ * @param string $slug The slug name for the generic template.
+ * @param string $name The name of the specialised template.
+ */
+function get_generic_template( $slug, $name = null ) {
+	do_action( "get_generic_template_{$slug}", $name );
+
+	$templates = array();
+	if ( isset($name) )
+		$templates[] = "{$slug}-{$name}.php";
+
+	$templates[] = "{$slug}.php";
+
+	locate_template($templates, true);
+}
+
 /**
  * Display search form.
  *