How to restrict wp-admin and prevent upload errors

Question

I need to restrict wp-admin access to all users who cant manage_options and still let users add media on the front end.

function wpse_11244_restrict_admin() {
    if ( ! current_user_can( 'manage_options' )  && $_SERVER['PHP_SELF'] != '/wp-admin/admin-ajax.php' ) {
        wp_redirect( home_url() );
    }
}
add_action( 'admin_init', 'wpse_11244_restrict_admin', 1 );

I found this code on stack overflow and it works great for my disabling the backend. The only hiccup I have found is when I go to add media on a front end post I get the following error.

When I refresh the page and click add media I now see the image that showed the upload error.

The image does upload but the only way the user would know that is if they refreshed.

How can I disable backend access for everything and still allow them to upload media?

Answer 1

You just need one extra thing for this.

Here is the code I typically use to do what you are doing:

function pws_block_admin() {

    if (
        // Look for the presence of /wp-admin/ in the url
        stripos($_SERVER['REQUEST_URI'],'/wp-admin/') !== false
        &&
        // Allow calls to async-upload.php
        stripos($_SERVER['REQUEST_URI'],'async-upload.php') === false
        &&
        // Allow calls to admin-ajax.php
        stripos($_SERVER['REQUEST_URI'],'admin-ajax.php') === false
    ) {
        if ( !current_user_can('manage_options') ) {
            $redirect_to = home_url();
            wp_redirect($redirect_to, 302);
        }
    }
}
add_action('admin_init', 'pws_block_admin', 0);

It looks like you are just missing the exclusion for allowing async-upload.php to work.