custom user role wordpress - grant guest access to edit.php without insert/update/delete

Question

I am working on a site where I want to show customers a demo-version of a product. To do this they can login with a guest-account, I have created this role as follows

add_role('guest', __('Guest'),
    array(
          'read'    => true
    )
);

When I login as a guest I get redirected to and get to see the overview-page /admin.php?page=my_overview, so this does work, but when the guest clicks on any item in this overview I get a message saying: You don't have permission to access this page.

These items refer to pages like: /profile.php /edit.php /users.php /admin.php Since using these pages is a basic part of my products functionality, I want to grant the guest account access to these pages, but don't let them insert/update/delete any data which is shown on those pages.

I have tried adding multiple different privileges i.e. edit_posts, edit_private_posts, edit_private_pages, read_private_posts, read_private_pages, but I can't get it to work right.

I would like to achieve this guest account with specific permissions without the use of any plugin. Basicly I want to create a user that can do the same as an Author, but without any INSERTs/UPDATEs/DELETEs on my demo-site to the database

I don't know if it is even possible, but any help would be appreciated.

Answer 1

After you've created the new role, you need to add the capability to it using add_cap. Check here for more info: https://codex.wordpress.org/Function_Reference/add_cap

I think that for your particular case, you could replicate an Author but then remove certain capabilities using remove_cap https://codex.wordpress.org/Function_Reference/remove_cap