options, and transients, and theme mods — oh my!

Options, and Transients, and Theme Mods — Oh my!

WordCamp St. Louis March 1, 2014

Konstantin ObenlandChairman Of Height at Automattic

!@obenland

konstantin.obenland.it

get_option() queries the database every time it is called.

True or False?

Transients are Options with an expiration date.

True or False?

wp-includes/option.php

Options vs. TransientsChoose one.

Options API

A simple and way of storing arbitrary data in the database.

get_option()

Is it in $all_options?

Is it in $wp_cache?

Is it in the database? Add to $wp_cache

Return value.

Return $default.

No

No

No

Yes

Yes

Yes

What are Notoptions?

Well, they are not options!

Is it in $all_options?

Is it in $wp_cache?

Is it in the database? Add to $wp_cache

Return value.

Return $default.

No

No

No

Yes

Yes

Yes

get_option()

Is it in $all_options?

Is it in $wp_cache?

Is it in the database? Add to $wp_cache

Return value.

Return $default.

No

No

No

Yes

Yes

Yes

Is it in $notoptions?

NoYes

Add to $notopions

get_option()

Transients API

A simple way of storing cached data.

Transients API ↓

Object Cache API ↓

WP_Object_Cache

They may use the Options API.

They can optionally expire.

function get_transient( $transient ) { !

if ( wp_using_ext_object_cache() ) { return wp_cache_get( $transient, 'transient' ); !

} else { // Check wp_load_all_options() !

return get_option( $transient_option ); } }

function set_transient( $transient, $value, $expiration = 0 ) { // Check for external object cache and use it. // Check DB for existing value and update expiration. // Add an option with the expiration of this transient. // Add the transient value to the DB. }

function get_my_data() { $data = get_transient( 'my_data' ); if ( false === $data ) { $data = $wpdb->get_results( $query ); set_transient( 'my_data', $data, DAY_IN_SECONDS ); } !

// Do something with $data. !

return $data; }

function get_my_data() { $data = wp_cache_get( 'my_data', 'my_group' ); if ( false === $data ) { $data = $wpdb->get_results( $query ); wp_cache_set( 'my_data', $data, 'my_group', DAY_IN_SECONDS ); } !

// Do something with $data. !

return $data; }

External Object Cache

By default, the built-in the object cache is non-persistent.

Pluggable, to allow for third party object caches.

Most popular: APC & Memcached

Source: Grokking the WordPress Object Cache; Tollmanz, Zack.

Recommended Reading

http://vip.wordpress.com/documentation/caching/

http://tollmanz.com/core-caching-concepts-in-wordpress/

http://tollmanz.com/grokking-the-wp-object-cache/

http://scotty-t.com/2012/01/20/wordpress-memcached/

Theme Mods

set_theme_mod( $name, $value ); get_theme_mod( $name, $default = false ); remove_theme_mod( $name ); !

get_theme_mods(); remove_theme_mods();

function get_theme_mod( $name, $default = false ) { $mods = get_option( 'theme_mods_' . get_option( 'stylesheet' ) ); !

if ( isset( $mods[ $name ] ) ) return $mods[ $name ]; !

return $default; }

Site Options & Site Transients

Uses the sitemeta table on Multisite.

User Settings & User Options

User Settings

User Settings

Primary examples are the expansion/collapse of the admin menu, and switching between text and visual. These can happen without a form submit, and you wouldn't want to fire an XHR request every time just to save the previous state.

—Andrew Nacin

User OptionsUses the User Meta API

But!

User Options vs. User Meta

Thank you!

Konstantin Obenland@obenland

konstantin.obenland.it