# Module `0x1::role` A generic module for role-based access control (RBAC). - [Resource `Role`](#0x1_role_Role) - [Constants](#@Constants_0) - [Function `assign_role`](#0x1_role_assign_role) - [Function `revoke_role`](#0x1_role_revoke_role) - [Function `has_role`](#0x1_role_has_role) - [Function `assert_has_role`](#0x1_role_assert_has_role)

use 0x1::error;
use 0x1::signer;

## Resource `Role`

struct Role<Type> has key

Fields

dummy_field: bool

## Constants

const EROLE: u64 = 0;

## Function `assign_role` Assign the role to the account. The caller must pass a witness, so is expected to be a function of the module that defines Type.

public fun assign_role<Type>(to: &signer, _witness: &Type)

Implementation

public fun assign_role<Type>(to: &signer, _witness: &Type) {
    assert!(!has_role<Type>(signer::address_of(to)), error::already_exists(EROLE));
    move_to<Role<Type>>(to, Role<Type>{});
}

## Function `revoke_role` Revoke the role from the account. The caller must pass a witness, so is expected to be a function of the module that defines Type.

public fun revoke_role<Type>(from: &signer, _witness: &Type)

Implementation

public fun revoke_role<Type>(from: &signer, _witness: &Type) acquires Role {
    assert!(has_role<Type>(signer::address_of(from)), error::not_found(EROLE));
    let Role<Type>{} = move_from<Role<Type>>(signer::address_of(from));
}

## Function `has_role` Return true iff the address has the role.

public fun has_role<Type>(addr: address): bool

Implementation

public fun has_role<Type>(addr: address): bool {
    exists<Role<Type>>(addr)
}

## Function `assert_has_role` assert! that the account has the role.

public fun assert_has_role<Type>(account: &signer)

Implementation

public fun assert_has_role<Type>(account: &signer) {
    assert!(has_role<Type>(signer::address_of(account)), error::not_found(EROLE));
}