WP_Rewrite Isn't As Scary As You Think
About Me
- Team Custom Lead at Automattic, the company behind WordPress.com
- Formerly a Senior WordPress Developer with Oomph, Inc. working on the WordPress.com VIP platform
- 3+ years developing WordPress themes and plugins
- WordPress Core Contributor
- WordCamp Boston Organizer
- Boston WordPress Meetup organizer
- Plugin Author
What Does WP_Rewrite Give Us?
Pretty permalinks!
http://ethitter.com/2013/08/year-in-review/
vs
http://ethitter.com/?p=3886
But How?
Magic!
But How?
Okay, it's not really magic. Sorry to disappoint.
Instead, it's all about Regular Expressions.
But How?
WordPress uses the chosen Permalink structure to build Regular Expressions that translate a pretty permalink to arguments for WP_Query.
/2013/08/year-in-review/ becomes:
array(
'year' => '2013',
'month' => '08',
'name' => 'year-in-review',
)
Where Are These Regular Expressions?
In the database, specifically the options table.
The array of rewrite rules are stored in an option named rewrite_rules.
Rewrite Rule?!? Regular Expression?!?
"([0-9]{4})/([0-9]{1,2})/([^/]+)(/[0-9]+)?/?$"
=>
"year=$matches[1]&monthnum=$matches[2]
&name=$matches[3]&page=$matches[4]"
Creating Your Own
You're in luck, WP provides lots of options!
add_rewrite_rule()add_rewrite_endpoint()generate_rewrite_rulesactionrewrite_rules_arrayfilter
Not an exhaustive list
Add a new rule: add_rewrite_rule()
add_rewrite_rule( $regex, $redirect, $position )
add_rewrite_rule(
"([0-9]{4})/([0-9]{1,2})/([^/]+)(/[0-9]+)?/?$",
"year=$matches[1]&monthnum=$matches[2]
&name=$matches[3]&page=$matches[4]",
"top"
)
Add a new endpoint: add_rewrite_endpoint()
add_rewrite_endpoint( $endpoint )
add_rewrite_endpoint( 'feed' )
add_rewrite_endpoint( 'print' )
Modify WP_Rewrite behaviour
Use the generate_rewrite_rules action.
- Passes one argument, the current
WP_Rewriteobject. - Useful if you need context when tweaking rules.
Modify rewrite rules
Use the rewrite_rules_array filter.
- Passes a single argument, the complete array of rewrite rules.
- Useful for modifying rules when context is irrelevant.
- Useful when bulk-adding rules, say in a plugin.
Resources
Questions?