详解WordPress开发中wp_title()函数的用法

$m = get_query_var('m');
$year = get_query_var('year');
$monthnum = get_query_var('monthnum');
$day = get_query_var('day');
$search = get_query_var('s');
$title = '';

$t_sep = '%WP_TITILE_SEP%'; // Temporary separator,for accurate flipping,if necessary

// If there is a post
if ( is_single() || ( is_home() && !is_front_page() ) || ( is_page() && !is_front_page() ) ) {
$title = single_post_title( '',false );
}

// If there's a category or tag
if ( is_category() || is_tag() ) {
$title = single_term_title( '',false );
}

// If there's a taxonomy
if ( is_tax() ) {
$term = get_queried_object();
$tax = get_taxonomy( $term->taxonomy );
$title = single_term_title( $tax->labels->name . $t_sep,false );
}

// If there's an author
if ( is_author() ) {
$author = get_queried_object();
$title = $author->display_name;
}

// If there's a post type archive
if ( is_post_type_archive() )
$title = post_type_archive_title( '',false );

// If there's a month
if ( is_archive() && !empty($m) ) {
$my_year = substr($m,4);
$my_month = $wp_locale->get_month(substr($m,4,2));
$my_day = intval(substr($m,6,2));
$title = $my_year . ( $my_month ? $t_sep . $my_month : '' ) . ( $my_day ? $t_sep . $my_day : '' );
}

// If there's a year
if ( is_archive() && !empty($year) ) {
$title = $year;
if ( !empty($monthnum) )
$title .= $t_sep . $wp_locale->get_month($monthnum);
if ( !empty($day) )
$title .= $t_sep . zeroise($day,2);
}

// If it's a search
if ( is_search() ) {
/ translators: 1: separator,2: search phrase /
$title = sprintf(__('Search Results %1$s %2$s'),$t_sep,strip_tags($search));
}

// If it's a 404 page
if ( is_404() ) {
$title = __('Page not found');
}

$prefix = '';
if ( !empty($title) )
$prefix = " $sep ";

// Determines position of the separator and direction of the breadcrumb
if ( 'right' == $seplocation ) { // sep on right,so reverse the order
$title_array = explode( $t_sep,$title );
$title_array = array_reverse( $title_array );
$title = implode( " $sep ",$title_array ) . $prefix;
} else {
$title_array = explode( $t_sep,$title );
$title = $prefix . implode( " $sep ",$title_array );
}

$title = apply_filters('wp_title',$title,$sep,$seplocation);

// Send it out
if ( $display )
echo $title;
else
return $title;

}