Gravity Forms granular form capabilities management

/**
 * Gravity Forms granular form capabilities management. see usage below
 *
 * Usage:
 * install Members plugin http://wordpress.org/extend/plugins/members/
 * edit the capabilities for a role (ie. editor)
 * add a new capabilty for each form users with that role can access
 * ie. add a capability called gravityforms_manage_form_3 to enable the user to view only form with id 3
 *
 * Caveat: the entries of the first form sorted alphabetically by title will always be visible, so add a placeholder titles something like "0 form"
 */
function smc_granular_form_management( $all_caps, $cap, $args ) {
    $cap = reset( $cap );

    if ( strpos( $cap, 'gravityforms_' ) !== 0 )
        return $all_caps;

    // save initial values
    $view_entries = isset( $all_caps['gravityforms_view_entries'] ) ? $all_caps['gravityforms_view_entries'] : 0;
    $export_entries = isset( $all_caps['gravityforms_export_entries'] ) ? $all_caps['gravityforms_export_entries'] : 0;
    $edit_forms = isset( $all_caps['gravityforms_edit_forms'] ) ? $all_caps['gravityforms_edit_forms'] : 0;

    // add these so that the menus show up
    $all_caps['gravityforms_view_entries'] = 1;
    $all_caps['gravityforms_export_entries'] = 1;
    $all_caps['gravityforms_edit_forms'] = 1;

    // viewing entries, editing form
    $form_id = isset( $_GET['id'] ) ? $_GET['id'] : null;

    // exporting entries
    if ( ! $form_id )
        $form_id = isset( $_POST['export_form'] ) ? $_POST['export_form'] : null;

    // see if the capability exists for this form for this user
    $per_form_cap = 'gravityforms_manage_form_' . $form_id;

    if ( $form_id && isset( $all_caps[ $per_form_cap ] ) && 1 == $all_caps[ $per_form_cap ] ) {
        // enable all caps when viewing authorized form
        $all_caps['gravityforms_edit_entries'] = 1;
        $all_caps['gravityforms_edit_entry_notes'] = 1;
        $all_caps['gravityforms_edit_forms'] = 1;
        $all_caps['gravityforms_export_entries'] = 1;
        $all_caps['gravityforms_delete_entries'] = 1;
        $all_caps['gravityforms_preview_forms'] = 1;
        $all_caps['gravityforms_view_entries'] = 1;
        $all_caps['gravityforms_view_entry_notes'] = 1;
    } elseif ( $form_id ) {
        // return caps to defaults when on potentially unauthorized form
        $all_caps['gravityforms_view_entries'] = $view_entries;
        $all_caps['gravityforms_export_entries'] = $export_entries;
        $all_caps['gravityforms_edit_forms'] = $edit_forms;
    }

    return $all_caps;
}
add_filter( 'user_has_cap', 'smc_granular_form_management', 10, 3 );