URL rewrite in theme doesn't seem to be working

Question

so I was asked to create url rewrites for one of the websites we're working on, but the thing is the test rewrite I did, just to try it out, is not really working.

here's the code I put in the functions.php file of the theme, to do url rewrites;

add_action( 'init', 'initialize_my_theme' );
function initialize_my_theme() {
    register_nav_menu('primary','MainMenu');
    add_filter( 'query_vars', 'campedia_set_query_vars' );
}

function campedia_set_query_vars( $vars ) {
    //array_push( $vars, 'learner_id' );
    return $vars;
}

function campedia_activate() {
    // register taxonomies/post types here
    flush_rewrite_rules();
    add_rewrite_rule('^nutrition/.+','view-profile/#','top');
}
register_activation_hook( __FILE__, 'campedia_activate' );

function campedia_deactivate() {
    flush_rewrite_rules();
}
register_deactivation_hook( __FILE__, 'campedia_deactivate' );

now I know you can't just take the examples from the wordpress site and expect everything to work - [cos their examples almost never work for the complicated stuff] - but I got practically all of this code from their website and it's not working, this is the third thing I tried and each time I'm just redirected to the home page. why?!

Answer 1

All the activation/deactivation/uninstall hooks only trigger for plugins.

Your best bet for a theme is the switch_theme hook, which has one argument: $new_theme. More info in that answer by @prettyboymp.