Sidebar only shows up on blog page

Question

I am currently working on a theme that uses a Page Sidebar for the Contact, About, Portfolio and Home pages, and a Blog Sidebar for the Blog page.

For some reason, the Page Sidebar is not showing up on any of its respective pages. I ran my theme through a WordPress theme validator, which gave me the following error message:

"Sidebars need to be registered in a custom function hooked to the widgets_init action. See: register_sidebar()."

For reference, here is the code that I used to register and create both sidebars:

function wpt_create_widget( $name, $id, $description ) {

    register_sidebar(array(
        'name' => __( $name ),   
        'id' => $id, 
        'description' => __( $description ),
        'before_widget' => '<div class="widget">',
        'after_widget' => '</div>',
        'before_title' => '<h2 class="module-heading">',
        'after_title' => '</h2>'
    ));

}

wpt_create_widget( 'Page Sidebar', 'page', 'Displays on the side of pages with a sidebar' );
wpt_create_widget( 'Blog Sidebar', 'blog', 'Displays on the side of pages in the blog section' );

Can anyone give me advice as to what specific PHP files I should be focusing on, to correct the issue? The files that I've potentially narrowed it down to are:

functions.php
page-sidebar-left.php
sidebar.php (Blog Sidebar)
sidebar-page.php (Page Sidebar)

Answer 1

The error you are getting is because you must add the registered sidebar to widgets_init.

add_action( 'widgets_init', 'wpa199335_page_sidebar' );

function wpa199335_page_sidebar(){
    register_sidebar(array(
        'name' => __( 'Page Sidebar'),
        'id' => 'page',
        'description' => __( 'Displays on the side of pages with a sidebar' ),
        'before_widget' => '<div class="widget">',
        'after_widget' => '</div>',
        'before_title' => '<h2 class="module-heading">',
        'after_title' => '</h2>'
    ));
}

That will only register the area to put widgets into. For the sidebar to display on a page you will need to use the following in a template file or your functions.php.

dynamic_sidebar( 'page' );