为wordpress添加面包屑导航
文章目录
面包屑导航（英语：Breadcrumb Trail）是在用户界面中的一种导航辅助。它是用户一个在程序或文件中确定和转移他们位置的一种方法。更多介绍参考维基百科：面包屑导航
本文介绍一种非插件方式使用面包屑导航的方法，代码出自《WordPress Breadcrumbs Without a Plugin》，
代码如下（点击展开）：
function dimox_breadcrumbs() {
/* === OPTIONS === */
$text['home'] = 'Home'; // text for the 'Home' link
$text['category'] = 'Archive by Category "%s"'; // text for a category page
$text['search'] = 'Search Results for "%s" Query'; // text for a search results page
$text['tag'] = 'Posts Tagged "%s"'; // text for a tag page
$text['author'] = 'Articles Posted by %s'; // text for an author page
$text['404'] = 'Error 404'; // text for the 404 page
$show_current = 1; // 1 - show current post/page/category title in breadcrumbs, 0 - don't show
$show_on_home = 0; // 1 - show breadcrumbs on the homepage, 0 - don't show
$show_home_link = 1; // 1 - show the 'Home' link, 0 - don't show
$show_title = 1; // 1 - show the title for the links, 0 - don't show
$delimiter = ' » '; // delimiter between crumbs
$before = '<span class="current">'; // tag before the current crumb
$after = '</span>'; // tag after the current crumb
/* === END OF OPTIONS === */
global $post;
$home_link = home_url('/');
$link_before = '<span typeof="v:Breadcrumb">';
$link_after = '</span>';
$link_attr = ' rel="v:url" property="v:title"';
$link = $link_before . '<a' . $link_attr . ' href="%1$s">%2$s</a>' . $link_after;
$parent_id = $parent_id_2 = $post->post_parent;
$frontpage_id = get_option('page_on_front');
if (is_home() || is_front_page()) {
if ($show_on_home == 1) echo '<div class="breadcrumbs"><a href="' . $home_link . '">' . $text['home'] . '</a></div>';
} else {
echo '<div class="breadcrumbs" xmlns:v="http://rdf.data-vocabulary.org/#">';
if ($show_home_link == 1) {
echo '<a href="' . $home_link . '" rel="v:url" property="v:title">' . $text['home'] . '</a>';
if ($frontpage_id == 0 || $parent_id != $frontpage_id) echo $delimiter;
}
if ( is_category() ) {
$this_cat = get_category(get_query_var('cat'), false);
if ($this_cat->parent != 0) {
$cats = get_category_parents($this_cat->parent, TRUE, $delimiter);
if ($show_current == 0) $cats = preg_replace("#^(.+)$delimiter$#", "$1", $cats);
$cats = str_replace('<a', $link_before . '<a' . $link_attr, $cats);
$cats = str_replace('</a>', '</a>' . $link_after, $cats);
if ($show_title == 0) $cats = preg_replace('/ title="(.*?)"/', '', $cats);
echo $cats;
}
if ($show_current == 1) echo $before . sprintf($text['category'], single_cat_title('', false)) . $after;
} elseif ( is_search() ) {
echo $before . sprintf($text['search'], get_search_query()) . $after;
} elseif ( is_day() ) {
echo sprintf($link, get_year_link(get_the_time('Y')), get_the_time('Y')) . $delimiter;
echo sprintf($link, get_month_link(get_the_time('Y'),get_the_time('m')), get_the_time('F')) . $delimiter;
echo $before . get_the_time('d') . $after;
} elseif ( is_month() ) {
echo sprintf($link, get_year_link(get_the_time('Y')), get_the_time('Y')) . $delimiter;
echo $before . get_the_time('F') . $after;
} elseif ( is_year() ) {
echo $before . get_the_time('Y') . $after;
} elseif ( is_single() && !is_attachment() ) {
if ( get_post_type() != 'post' ) {
$post_type = get_post_type_object(get_post_type());
$slug = $post_type->rewrite;
printf($link, $home_link . '/' . $slug['slug'] . '/', $post_type->labels->singular_name);
if ($show_current == 1) echo $delimiter . $before . get_the_title() . $after;
} else {
$cat = get_the_category(); $cat = $cat[0];
$cats = get_category_parents($cat, TRUE, $delimiter);
if ($show_current == 0) $cats = preg_replace("#^(.+)$delimiter$#", "$1", $cats);
$cats = str_replace('<a', $link_before . '<a' . $link_attr, $cats);
$cats = str_replace('</a>', '</a>' . $link_after, $cats);
if ($show_title == 0) $cats = preg_replace('/ title="(.*?)"/', '', $cats);
echo $cats;
if ($show_current == 1) echo $before . get_the_title() . $after;
}
} elseif ( !is_single() && !is_page() && get_post_type() != 'post' && !is_404() ) {
$post_type = get_post_type_object(get_post_type());
echo $before . $post_type->labels->singular_name . $after;
} elseif ( is_attachment() ) {
$parent = get_post($parent_id);
$cat = get_the_category($parent->ID); $cat = $cat[0];
$cats = get_category_parents($cat, TRUE, $delimiter);
$cats = str_replace('<a', $link_before . '<a' . $link_attr, $cats);
$cats = str_replace('</a>', '</a>' . $link_after, $cats);
if ($show_title == 0) $cats = preg_replace('/ title="(.*?)"/', '', $cats);
echo $cats;
printf($link, get_permalink($parent), $parent->post_title);
if ($show_current == 1) echo $delimiter . $before . get_the_title() . $after;
} elseif ( is_page() && !$parent_id ) {
if ($show_current == 1) echo $before . get_the_title() . $after;
} elseif ( is_page() && $parent_id ) {
if ($parent_id != $frontpage_id) {
$breadcrumbs = array();
while ($parent_id) {
$page = get_page($parent_id);
if ($parent_id != $frontpage_id) {
$breadcrumbs[] = sprintf($link, get_permalink($page->ID), get_the_title($page->ID));
}
$parent_id = $page->post_parent;
}
$breadcrumbs = array_reverse($breadcrumbs);
for ($i = 0; $i < count($breadcrumbs); $i++) {
echo $breadcrumbs[$i];
if ($i != count($breadcrumbs)-1) echo $delimiter;
}
}
if ($show_current == 1) {
if ($show_home_link == 1 || ($parent_id_2 != 0 && $parent_id_2 != $frontpage_id)) echo $delimiter;
echo $before . get_the_title() . $after;
}
} elseif ( is_tag() ) {
echo $before . sprintf($text['tag'], single_tag_title('', false)) . $after;
} elseif ( is_author() ) {
global $author;
$userdata = get_userdata($author);
echo $before . sprintf($text['author'], $userdata->display_name) . $after;
} elseif ( is_404() ) {
echo $before . $text['404'] . $after;
}
if ( get_query_var('paged') ) {
if ( is_category() || is_day() || is_month() || is_year() || is_search() || is_tag() || is_author() ) echo ' (';
echo __('Page') . ' ' . get_query_var('paged');
if ( is_category() || is_day() || is_month() || is_year() || is_search() || is_tag() || is_author() ) echo ')';
}
echo '</div><!-- .breadcrumbs -->';
}
} // end dimox_breadcrumbs()
把以上代码放入functions.php中。
调用函数：
<?php if (function_exists('dimox_breadcrumbs')) dimox_breadcrumbs(); ?>
把调用函数放在需要显示面包屑导航的地方即可。
生成的面包屑导航会在
<div class="breadcrumbs"> </div>中，调整相应的css，即可自定义样式。比如
.breadcrumbs a:link {color:#FFFFFF;}设置链接颜色为白色。
这段代码首部的：
/* === OPTIONS === */
$text['home'] = 'Home'; // text for the 'Home' link
$text['category'] = 'Archive by Category "%s"'; // text for a category page
$text['search'] = 'Search Results for "%s" Query'; // text for a search results page
$text['tag'] = 'Posts Tagged "%s"'; // text for a tag page
$text['author'] = 'Articles Posted by %s'; // text for an author page
$text['404'] = 'Error 404'; // text for the 404 page
$show_current = 1; // 1 - show current post/page/category title in breadcrumbs, 0 - don't show
$show_on_home = 0; // 1 - show breadcrumbs on the homepage, 0 - don't show
$show_home_link = 1; // 1 - show the 'Home' link, 0 - don't show
$show_title = 1; // 1 - show the title for the links, 0 - don't show
$delimiter = ' » '; // delimiter between crumbs
$before = '<span class="current">'; // tag before the current crumb
$after = '</span>'; // tag after the current crumb
/* === END OF OPTIONS === */
即为相关功能选项，带注释的代码应该很容易理解，不再解释。
文章作者 ladder1984
上次更新 2013-10-31