php这种写法什么意思？解决方法

<br />
if ( defined('WP_USE_THEMES') && WP_USE_THEMES ) :<br />
	$template = false;<br />
	if     ( is_404()            && $template = get_404_template()            ) :<br />
	elseif ( is_search()         && $template = get_search_template()         ) :<br />
	elseif ( is_front_page()     && $template = get_front_page_template()     ) :<br />
	elseif ( is_home()           && $template = get_home_template()           ) :<br />
	elseif ( is_post_type_archive() && $template = get_post_type_archive_template() ) :<br />
	elseif ( is_tax()            && $template = get_taxonomy_template()       ) :<br />
	elseif ( is_attachment()     && $template = get_attachment_template()     ) :<br />
		remove_filter('the_content', 'prepend_attachment');<br />
	elseif ( is_single()         && $template = get_single_template()         ) :<br />
	elseif ( is_page()           && $template = get_page_template()           ) :<br />
	elseif ( is_category()       && $template = get_category_template()       ) :<br />
	elseif ( is_tag()            && $template = get_tag_template()            ) :<br />
	elseif ( is_author()         && $template = get_author_template()         ) :<br />
	elseif ( is_date()           && $template = get_date_template()           ) :<br />
	elseif ( is_archive()        && $template = get_archive_template()        ) :<br />
	elseif ( is_comments_popup() && $template = get_comments_popup_template() ) :<br />
	elseif ( is_paged()          && $template = get_paged_template()          ) :<br />
	else :<br />
		$template = get_index_template();<br />
	endif;<br />
	/**<br />
	 * Filter the path of the current template before including it.<br />
	 *<br />
	 * @since 3.0.0<br />
	 *<br />
	 * @param string $template The path of the template to include.<br />
	 */<br />
	if ( $template = apply_filters( 'template_include', $template ) )<br />
		include( $template );<br />
	return;<br />
endif;<br />