WordPress Custom Theme > Execute "Setup" Code on Activation only? - php

Question

I have some setup code in my functions.php file that sets permalinks and adds categories that are used by the theme. I only want this code to run when the theme is first activated. There is no need for the code to run again. However, by placing it in the functions.php file, it runs each and every time a page on the website is loaded.
Is there an alternative method to use so that this code only runs when the custom theme is first activated?

Answer 1

In wp-includes/theme.php you’ll find the function switch_theme(). It offers an action hook:
/**
* Switches current theme to new template and stylesheet names.
*
* #since unknown
* #uses do_action() Calls 'switch_theme' action on updated theme display name.
*
* #param string $template Template name
* #param string $stylesheet Stylesheet name.
*/
function switch_theme($template, $stylesheet) {
update_option('template', $template);
update_option('stylesheet', $stylesheet);
delete_option('current_theme');
$theme = get_current_theme();
do_action('switch_theme', $theme);
}
So you may use this in your functions.php:
function my_activation_settings($theme)
{
if ( 'Your Theme Name' == $theme )
{
// do something
}
return;
}
add_action('switch_theme', 'my_activation_settings');
Just an idea; I haven’t tested it.

Answer 2

Another one to look at would be after_switch_theme it is also in wp-includes/theme.php
It seems to be a hook run in check_theme_switched
/**
* Checks if a theme has been changed and runs 'after_switch_theme' hook on the next WP load
*
* #since 3.3.0
*/
function check_theme_switched() {
if ( $stylesheet = get_option( 'theme_switched' ) ) {
$old_theme = wp_get_theme( $stylesheet );
// Prevent retrieve_widgets() from running since Customizer already called it up front
if ( get_option( 'theme_switched_via_customizer' ) ) {
remove_action( 'after_switch_theme', '_wp_sidebars_changed' );
update_option( 'theme_switched_via_customizer', false );
}
if ( $old_theme->exists() ) {
/**
* Fires on the first WP load after a theme switch if the old theme still exists.
*
* This action fires multiple times and the parameters differs
* according to the context, if the old theme exists or not.
* If the old theme is missing, the parameter will be the slug
* of the old theme.
*
* #since 3.3.0
*
* #param string $old_name Old theme name.
* #param WP_Theme $old_theme WP_Theme instance of the old theme.
*/
do_action( 'after_switch_theme', $old_theme->get( 'Name' ), $old_theme );
} else {
/** This action is documented in wp-includes/theme.php */
do_action( 'after_switch_theme', $stylesheet );
}
flush_rewrite_rules();
update_option( 'theme_switched', false );
}
}`
add_action('after_switch_theme', 'my_activation_settings');
I think both ways work just something else to look into :)