Question

add_rewrite_tag( string $tag,  string $regex,  string $query = '' )

Add a new rewrite tag (like %postname%).

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description

The $query parameter is optional. If it is omitted you must ensure that you call this on, or before, the ‘init’ hook. This is because $query defaults to "$tag=", and for this to work a new query var has to be added.

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参数

$tag

(string) (Required) Name of the new rewrite tag.

$regex

(string) (Required) Regular expression to substitute the tag for in rewrite rules.

$query

(string) (Optional) String to append to the rewritten query. Must end in '='.

Default value: ''

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源代码

File: wp-includes/rewrite.php

function add_rewrite_tag( $tag, $regex, $query = '' ) {
	// validate the tag's name
	if ( strlen( $tag ) < 3 || $tag[0] != '%' || $tag[ strlen($tag) - 1 ] != '%' )
		return;

	global $wp_rewrite, $wp;

	if ( empty( $query ) ) {
		$qv = trim( $tag, '%' );
		$wp->add_query_var( $qv );
		$query = $qv . '=';
	}

	$wp_rewrite->add_rewrite_tag( $tag, $regex, $query );
}

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更新日志

Version	description
2.1.0	Introduced.

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相关函数

Uses

• wp-includes/class-wp.php: WP::add_query_var()
• wp-includes/class-wp-rewrite.php: WP_Rewrite::add_rewrite_tag()

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Used By

• wp-includes/class-wp-taxonomy.php: WP_Taxonomy::add_rewrite_rules()
• wp-includes/class-wp-post-type.php: WP_Post_Type::add_rewrite_rules()

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User Contributed Notes

1. Skip to note content You must log in to vote on the helpfulness of this noteVote results for this note: 1You must log in to vote on the helpfulness of this note Contributed by bcworkz

   In the following examples, imagine a site has a custom taxonomy ‘location’ and all posts are assigned a location term like “Paris” or “Madrid”. We add a rewrite tag “%location%” to establish the location query var. We also add a rewrite rule so that an URL such as example.com/goto/madrid/budget-lodging/ is properly handled.

   add_action('init', 'add_my_rewrites');
   function add_my_rewrites() {
       add_rewrite_tag('%location%', '([^&]+)', 'location=');
       add_rewrite_rule('^goto/([^/]*)/([^/]*)/?','index.php?location=$matches[1]&name=$matches[2]','top');
   }

   Even though rewrite tags look just like permalink structure tags, if you try to use your rewrite tag in a permalink structure, the URLs generated by WordPress will look something like example.com/goto/%location%/budget-lodging/. The proper term does not replace the rewrite tag as you might expect. To make your tag behave like a structure tag, use the “post_link” filter to replace the tag with the proper term.

   // Assign value to %location% rewrite tag
   add_filter('post_link', 'my_filter_post_link', 10, 2 );
   function my_filter_post_link( $permalink, $post ) {
   
       // bail if %location% tag is not present in the url:
       if ( false === strpos( $permalink, '%location%'))
           return $permalink;
   
       $terms = wp_get_post_terms( $post->ID, 'location');
       // set location, if no location is found, provide a default value.
       if ( 0 < count( $terms ))
           $location = $terms[0]->slug;
       else
           $location = 'timbuktu';
       $location = urlencode( $location );
       $permalink = str_replace('%location%', $location , $permalink );
    
       return $permalink;
   }

   Anytime you change something 相关函数 to the Rewrite API, don’t forget to flush the rewrite rules! This can be done without code by going to Permalink Settings and clicking Save Changes. You don’t actually need to make any changes on the settings screen.