Switching theme only changes style sheet being used

Question

I have a plugin that I'm using to switch themes for a specific user for development. When logged in as that user they see the different style sheet but the themes files, function.php, header.php, etc are the active theme for everyone else.

What I am doing wrong?

function change_user_theme($template) {
    global $user_ID;

    if ( in_array( $user_ID, array( 5 ) ) ) {
        $template = 'fezmobile';
    } else {
        $template = 'fezforprez';
    }

    return $template;
}

add_filter('template', 'change_user_theme');
add_filter('stylesheet', 'change_user_theme');
add_filter('option_template', 'change_user_theme');
add_filter('option_stylesheet', 'change_user_theme');

Answer 1

Take a look at my answer here:

Switch Theme Through Options Panel

The code is as follows:

add_action( 'setup_theme', 'switch_user_theme' );
function switch_user_theme() {
    if ( in_array( wp_get_current_user()->ID, array( 5 ) ) ) {
         $user_theme = 'fezforprez';
         add_filter( 'template', create_function( '$t', 'return "' . $user_theme . '";' ) );
         add_filter( 'stylesheet', create_function( '$s', 'return "' . $user_theme . '";' ) );
    }
}

You have to swap the template and stylesheet on the setup_theme action.