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PermissionsEnumerable

import "@thirdweb-dev/contracts/extension/PermissionsEnumerable.sol";

The PermissionsEnumerable extension provides role-based access control: you can create roles and write custom logic in your smart contract that depends on whether a given wallet holds a given role. The Enumerable part provides the capability to view all the addresses holding a specific role.

Usage

This is an example smart contract demonstrating how to inherit from this extension and override the functions to add (optional) custom functionality.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@thirdweb-dev/contracts/extension/PermissionsEnumerable.sol";

contract MyContract is PermissionsEnumerable {
// Any `bytes32` value is a valid role. You can create roles by defining them like this.
bytes32 public constant NUMBER_ROLE = keccak256("NUMBER_ROLE");

// See comments for `setNumber`, below.
uint256 public number;

/**
* The `PermissionsEnumerable` contract makes an already defined role available: the `DEFAULT_ADMIN_ROLE`.
*
* As an EXAMPLE, we grant the deployer of the contract this admin role.
*/
constructor() {
_setupRole(DEFAULT_ADMIN_ROLE, msg.sender);
}

/**
* EXAMPLE: here we have a function that we want to restrict only to holders of `NUMBER_ROLE`.
*
* To accomplish this, we use the `onlyRole` modifier made available by `PermissionsEnumerable`, and
* pass it `NUMBER_ROLE` as an argument.
*/
function setNumber(uint256 _newNumber) public onlyRole(NUMBER_ROLE) {
number = _newNumber;
}
}

SDK Usage

By adding this extension to a smart contract, the following features, hooks and functions are unlocked in the SDK:

Base Contracts Implementing This Extension

None of the base contracts implement this extension.

Full API Reference

PermissionsEnumerable inherits from the Permissions extension so includes all of the functions in that extension. It also includes the following functions:

getRoleMember
function getRoleMember(bytes32 role, uint256 index) external view returns (address member);
  • Returns one of the accounts that have role. index must be a value between 0 and the value of getRoleMemberCount at the time, non-inclusive.
  • Parameters:
    • role: keccak256 hash of the role. e.g. keccak256("TRANSFER_ROLE")
    • index: Index in list of current members for the role.
getRoleMemberCount
function getRoleMemberCount(bytes32 role) external view returns (uint256 count);
  • Returns the number of accounts that have role. Can be used together with getRoleMember to enumerate all bearers of a role.
  • Parameters:
    • role: keccak256 hash of the role. e.g. keccak256("TRANSFER_ROLE")