Rewrites Review, WCNYC 2012

An introduction to the Rewrites API.

Transcript

1. Eric Andrew Lewis @ericandrewlewis REWRITES REVIEW
2. ¡  Pretty Permalinks ¡  Server-side manipulation of incoming URL requests No rewrites §  www.nytimes.com/article.php?article_id=349590 Using rewrites §  www.nytimes.com/2012/06/07/face-eater-feasts-in-miami WHAT ARE REWRITES?
3. ¡  User-Friendly §  Self-Describing URLs ¡  SEO-Friendly §  Self-Describing URLs §  SEO bots usually cut off query arguments §  www.nytimes.com/article.php?article_name=face-eater-feasts-in-miami > www.nytimes.com/article.php ¡  Security §  File locations and query arguments aren’t public. WHY REWRITE?
4. BUT HOW? Visitor requests URL Web server receives request Processes URL through a rewrite module Executes rewritten script Returns result to visitor www.nytimes.com/2012/06/07/ face-eater-feasts-in-miami index.php?pagename=face-eater-feasts-in-miami .htaccess file
5. WEB SERVER REWRITING IS SEPARATE FROM WORDPRESS REWRITING Web Server Rewrite Rules index.php (Load WordPress) WordPress Rewrite Rules
6. WEB SERVER REWRITING IS SEPARATE FROM WORDPRESS REWRITING Web Server Rewrite Rules index.php (Load WordPress) WordPress Rewrite Rules
7. # BEGIN WordPress <IfModule mod_rewrite.c> # "If" wrapper to ensure mod_rewrite is available RewriteEngine On RewriteBase / RewriteRule ^index\.php$ - [L] # No substitution, load index.php RewriteCond %{REQUEST_FILENAME} !-f # Path is not an existing file RewriteCond %{REQUEST_FILENAME} !-d # Path is not an existing directory RewriteRule . index.php [L] </IfModule> # END WordPress WEB SERVER REWRITE RULES ¡  Generated by WordPress ¡  Sends any pretty permalinks to WP’s index.php for processingt *example using Apache mod_rewrite
8. ¡  Redirect IE 6 users to Chrome download page COOL (AND NOT SO COOL) STUFF WITH .HTACCESS RewriteCond %{HTTP_USER_AGENT} MSIE\s7{1} RewriteRule . http://www.google.com/chrome/ [L] ¡  Access to variables like HTTP Headers, server internals, date/ time, requester’s info ¡  Block external access to image files RewriteCond %{HTTP_REFERER} !^https?://www\.yoursite\.com/ RewriteRule \.(?:gif|jpg|jpeg|png)$ /blocked.png [L]
9. WEB SERVER REWRITING IS SEPARATE FROM WORDPRESS REWRITING Web Server Rewrite Rules index.php (Load WordPress) WordPress Rewrite Rules
10. MAKEUP OF A WP REWRITE RULE URL to fetch, with WordPress query arguments index.php?tag=$matches[1] Would get set to index.php?tag=music Regular Expression to match against URL tag/([^/]+)/?$ Matches the URL www.yoursite.com/tag/music 1 2
11. category/(.+?)/?$ => index.php?category_name=$matches[1] category/(.+?)/page/?([0-9]{1,})/?$ => index.php?category_name=$matches[1]&paged=$matches[2] tag/([^/]+)/?$ => index.php?tag=$matches[1] search/(.+)/?$ => index.php?s=$matches[1] feed/(feed|rdf|rss|rss2|atom)/?$ => index.php?&feed=$matches[1] page/?([0-9]{1,})/?$ => index.php?&paged=$matches[1] ([0-9]{4})/([0-9]{1,2})/([0-9]{1,2})/page/?([0-9]{1,})/?$ => index.php?year=$matches[1]&monthnum=$matches[2]&day= $matches[3]&paged=$matches[4] SAMPLE OF WP REWRITE RULES
12. ¡  Built-in rewrites §  Post types §  Pages /sample-page (/post-name/) §  Posts /2012/06/09/wordcamp-happening-today (/year/monthnum/day/ post-name/) §  Taxonomies /category/wordpress-tricks/ ¡  Custom post types and taxonomies get auto-generated rewrite rules. §  CPT: product/case-of-yeungling §  Taxonomy: type-of-beer/american-pilsner EXAMPLES OF WP GENERATED URL STRUCTURES
13. What’s wrong with those URLS?
14. EXAMPLES OF CORE LIMITATIONS URLs for an online store ¡  /store/ - archive of all products ¡  /store/american-pilsner/ - archive of products under a custom taxonomy ¡  /store/american-pilsner/case-of-yuengling/ - single product prepended a custom taxonomy term Gracefully degrading archives for a custom post type ¡  /events/%year%/%monthnum%/%day%/%postname%/
15. Create custom rewrite rules
16. HOW WORDPRESS PROCESSES REWRITES IN ONE SLIDE Load rewrite rules and process • Take first rewrite rule regex that matches URL Allowed query variables turned into WP query variables. • Populate $wp_query object with query variables. Template loaded • WP Query Variables • Template Hierarchy
17. HOW WORDPRESS PROCESSES REWRITES IN ONE SLIDE foreach ( (array) $rewrite as $match => $query ) { // If the requesting file is the anchor of the match, prepend it to the path info. if ( ! empty($req_uri) && strpos($match, $req_uri) === 0 && $req_uri != $request ) $request_match = $req_uri . '/' . $request; if ( preg_match("#^$match#", $request_match, $matches) || preg_match("#^$match#", urldecode($request_match), $matches) ) { if ( $wp_rewrite->use_verbose_page_rules && preg_match( '/pagename=\$matches\[([0-9]+)\]/', $query, $varmatch ) ) { // this is a verbose page match, lets check to be sure about it if ( ! get_page_by_path( $matches[ $varmatch[1] ] ) ) continue; } // Got a match. $this->matched_rule = $match; break; } } wp-includes/class-wp.php:196-215 ¡  Process stored rewrites, if a rewrite rules is matched, set query variables.
18. How do you create custom rewrite rules?
19. REWRITES API add_permastruct() add_rewrite_rule() add_rewrite_endpoint() add_rewrite_tag() add_feed() flush_rewrite_rules()
20. ¡  add_rewrite_rule( $pattern, $rewritten_url, $position ) ¡  Adds one custom rewrite rule. ADD_REWRITE_RULE() add_action('init', 'register_store_rewrite_rules'); function register_store_rewrite_rules() { add_rewrite_rule('store/([^/]+)/?$', 'index.php? post_type=product&name=$matches[1]', 'top'); add_rewrite_rule('store/([^/]+)/([^/]+)/?$', 'index.php? post_type=product&name=$matches[2]', 'top'); }
21. ¡  Complex Rewrite Example §  Custom Post Type recipes, custom taxonomy for recipe group. §  /southern-cooking/roasted-okra/ (/custom-taxonomy-term/custom- post-name/) §  Matching rewrite rule is too general – /(^/)+/(^/)+/ - would catch all posts §  Is possible §  Create a rewrite rule for each taxonomy term §  /southern-cooking/(^/)+/ §  /chinese/(^/)+/ §  /amish-and-mennonite/(^/)+/ §  Easier to add a specific string to the rewrite rule §  /recipes/(^/)+/(^/)+/ §  /recipes/southern-cooking/roasted-okra/ THE MORE SPECIFIC THE BETTER
22. ¡  You’ve seen them before ¡  A string of rewrite tags that automatically generate rewrite rules §  Available in core: %year% %monthnum% %day% %hour% %minute% %second% %post_id% %postname% %category% %author% ¡  Can walk directories - creates piecemeal tag rewrites §  /%year%/ - /2012/ - all posts from 2012 §  /%year%/%monthnum%/ - /2012/06/ all posts from June 2012 §  /%year%/%monthnum%/%postname%/ - specific post ¡  Adds RSS feeds for each level of archives PERMASTRUCTS
23. Why would I ever need to do that?
24. EXAMPLES OF ADD_PERMASTRUCT() USES ¡  Author archives by first letter of last name §  /authors/%author_letter%/ ¡  Date archives for CPTs §  /event/%year%/%monthnum%/%day%/ ¡  Date archive for posts in a category by a specific author §  /%year%/%category%/%author%/ ¡  Whatever you can dream.
25. ¡  add_permastruct($name, $permastruct, $with_front, $ep_mask); ADD_PERMASTRUCT() add_action('init', 'register_event_post_type_permastruct'); function register_event_post_type_permastruct() { add_rewrite_tag('%event_cpt%', '(event)', 'post_type='); add_permastruct('events_date_archive', '%event_cpt%/%year%/%monthnum%/%day%/%postname %/', false); } add_filter('post_type_link', 'modify_event_permalink', 10, 2); function modify_event_permalink($permalink, $post) { if ( $post->post_type != 'event' ) return $permalink; $year = substr($post->post_date, 0, 4); $month = substr($post->post_date, 5, 2); $day = substr($post->post_date, 8, 2); $permalink = site_url() . '/event/'. $year . '/' . $month . '/' . $day . '/' . $post- >post_name; return $permalink; }
26. ENDPOINTS ¡  Add an extra custom string to the end of existing permastructs. §  View post in JSON format §  www.yoursite.com/a-post/json/ §  View a gallery of attached images to a post §  www.yoursite.com/a-post/gallery/ ¡  Opportunity to show a post’s data in a different format.
27. ADD_ENDPOINT() function register_gallery_endpoint() { add_rewrite_endpoint( 'gallery', EP_PERMALINK ); } add_action('template_redirect', 'catch_gallery_endpoint'); function catch_gallery_endpoint() { global $wp_query, $post; // if this is not a request for json or a singular object then bail if ( isset( $wp_query->query_vars['gallery'] ) && is_singular() ) { $post = get_queried_object(); locate_template('gallery.php', true, true); exit; } }
28. ¡  Rewrite API Basics by Stephen Harris §  http://wp.tutsplus.com/tutorials/creative-coding/the-rewrite-api-the- basics/ ¡  Helper class to add custom taxonomy to Post Permalinks ViperBond007 §  http://www.viper007bond.com/2011/10/07/code-snippet-helper- class-to-add-custom-taxonomy-to-post-permalinks/ ¡  Rewrite Endpoints API by Jon Cave §  http://make.wordpress.org/plugins/2012/06/07/rewrite-endpoints- api/ GOOD REFERENCES
29. Q & A