Code needed to only show users own posts in a multi-user account

Question

I am using WP3 and want to starting adding users (many users to a single blog) but when I give a new user an account, they can see all the posts in the admin including scheduled, drafts, pending review etc. I either need the users to ONLY view their own posts or only view their own published posts (but not scheduled, drafts, etc). The admin should be able to see everything.

Here is a link I found on this issue with a code but the code is not working in my functions.php

http://wordpress.org/support/topic/show-only-authors-posts-in-admin-panel-instead-of-all-posts

Answer 1

Put this into your functions.php file in your theme folder...

function query_set_only_author( $wp_query ) {
    global $current_user;
    if ( is_admin() && !current_user_can('manage_options') ) {
        $wp_query->set( 'author', $current_user->ID );
    }
}
add_action('pre_get_posts', 'query_set_only_author' );

Answer 2

Have a look here for a more complete solution (fixes the post count on the filter bar): Help to optimize some working code (to only show posts of logged in Author and fix post count)

Answer 3

I am also interested in finding a similar solution - but to also allow any co-author to view & edit the post.

The above code works great for single authors, but I use the co-author plugin which allows for nominating several authors to the same post (http://wordpress.org/extend/plugins/co-authors-plus/.

In this regard, it seems only the primary author can see the post - How can I allow all nominated co-authors to see the post also ?