自定义 WordPress Tag 和 Category 固定链接结构

对于 WordPress 比较熟悉的朋友应该知道，如果想修改文章(Post)的固定链接结构(Permalinks)，可以到 WordPress 后台管理界面进行修改，比如说，如果你想让页面地址都有一个 “news” 的前缀，形如：
http://www.webhek.com/news/hollow-world/
你可以在后台的“固定链接”设置界面将固定链接结构设置为 “/news/%postname%” 就行了。

但是，你会发现，只有文章页(Post)的链接结构上这样改的，而一般页面(Page)的链接结构没有变化，而且，标签(Tag)的链接结构也变成了”/news/%tag%”样子。

如果你想自定义标签(Tag)的固定链接，让它不随文章页(Post)的链接结构的变化而变化，让标签页(Tag)具有更个性的链接结构，怎么办呢？

或者，我还想自定义分类目录页(category)的固定链接结构，有什么办法？

我们是应该从 $wp_rewrite 对象下手。前提是要知道 $wp_rewrite 对象里数据结构究竟是怎样的，才能找出修改的方法，于是我把 $wp_rewrite 打印了出来，下面就是这个对象的内部结构：

WP_Rewrite Object
(
    [permalink_structure] => /post/%postname%.html
    [use_trailing_slashes] => 
    [author_base] => author
    [page_structure] => %pagename%.html
    [search_base] => search
    [comments_base] => comments
    [pagination_base] => page
    [comments_pagination_base] => comment-page
    [feed_base] => feed
    [front] => /post/
    [root] => 
    [index] => index.php
    [matches] => 
    [rules] => 
    [extra_rules] => Array
        (
        )

    [extra_rules_top] => Array
        (
        )

    [non_wp_rules] => Array
        (
        )

    [extra_permastructs] => Array
        (
            [category] => Array
                (
                    [with_front] => 
                    [ep_mask] => 512
                    [paged] => 1
                    [feed] => 1
                    [forcomments] => 
                    [walk_dirs] => 1
                    [endpoints] => 1
                    [struct] => cat/%category%
                )

            [post_tag] => Array
                (
                    [with_front] => 
                    [ep_mask] => 1024
                    [paged] => 1
                    [feed] => 1
                    [forcomments] => 
                    [walk_dirs] => 1
                    [endpoints] => 1
                    [struct] => tag/%post_tag%
                )

            [post_format] => Array
                (
                    [with_front] => 1
                    [ep_mask] => 0
                    [paged] => 1
                    [feed] => 1
                    [forcomments] => 
                    [walk_dirs] => 1
                    [endpoints] => 1
                    [struct] => /post/type/%post_format%
                )

        )

    [endpoints] => Array
        (
        )

    [use_verbose_rules] => 
    [use_verbose_page_rules] => 1
    [rewritecode] => Array
        (
            [0] => %year%
            [1] => %monthnum%
            [2] => %day%
            [3] => %hour%
            [4] => %minute%
            [5] => %second%
            [6] => %postname%
            [7] => %post_id%
            [8] => %author%
            [9] => %pagename%
            [10] => %search%
            [11] => %category%
            [12] => %post_tag%
            [13] => %post_format%
        )

    [rewritereplace] => Array
        (
            [0] => ([0-9]{4})
            [1] => ([0-9]{1,2})
            [2] => ([0-9]{1,2})
            [3] => ([0-9]{1,2})
            [4] => ([0-9]{1,2})
            [5] => ([0-9]{1,2})
            [6] => ([^/]+)
            [7] => ([0-9]+)
            [8] => ([^/]+)
            [9] => ([^/]+?)
            [10] => (.+)
            [11] => (.+?)
            [12] => ([^/]+)
            [13] => ([^/]+)
        )

    [queryreplace] => Array
        (
            [0] => year=
            [1] => monthnum=
            [2] => day=
            [3] => hour=
            [4] => minute=
            [5] => second=
            [6] => name=
            [7] => p=
            [8] => author_name=
            [9] => pagename=
            [10] => s=
            [11] => category_name=
            [12] => tag=
            [13] => post_format=
        )

    [feeds] => Array
        (
            [0] => feed
            [1] => rdf
            [2] => rss
            [3] => rss2
            [4] => atom
        )

)

这下就清楚了，之前我们修改页面(Page)的固定链接结构是修改了 [page_structure] => %pagename%.html ，而修改标签页(Tag)的固定链接结构很显然是要修改 [extra_permastructs][post_tag][struct] => tag/%post_tag% 这个值，而修改分类目录页(Category)的固定链接，自然是修改 [extra_permastructs][category][struct] => cat/%category% 的值。

下面是具体的修改代码：

function custom_page_rules() {
    global $wp_rewrite;
    //修改page的固定链接结构
    $wp_rewrite->page_structure = $wp_rewrite->root . 'post/%pagename%.html'; 
    //修改tag的固定链接结构
    $wp_rewrite->extra_permastructs['post_tag']['with_front'] = '';
    $wp_rewrite->extra_permastructs['post_tag']['struct'] = 'tag/%post_tag%';
}
add_action( 'init', 'custom_page_rules' );

把上面的这段代码放到 function.php 里，就能自定义 1）Page的固定链接结构，2）Tag页的固定链接结构。

修改分类目录页(Category)的固定链接也是同样的道理。

严谨的说， WordPress 里并没有提供安全的接口来实现这些修改，上面的这些方法属于不安全的入侵，如果某天 v 升级了数据结构，那这些修改方法将会失效，甚至会引起系统错误等，所以，有一定风险。

来源： Web 骇客