Working on a custom resolver

customResolver.sol

pragma solidity >=0.4.24;

interface ENS {

    // Logged when the owner of a node assigns a new owner to a subnode.
    event NewOwner(bytes32 indexed node, bytes32 indexed label, address owner);

    // Logged when the owner of a node transfers ownership to a new account.
    event Transfer(bytes32 indexed node, address owner);

    // Logged when the resolver for a node changes.
    event NewResolver(bytes32 indexed node, address resolver);

    // Logged when the TTL of a node changes
    event NewTTL(bytes32 indexed node, uint64 ttl);

    // Logged when an operator is added or removed.
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    function setRecord(bytes32 node, address owner, address resolver, uint64 ttl) external;
    function setSubnodeRecord(bytes32 node, bytes32 label, address owner, address resolver, uint64 ttl) external;
    function setSubnodeOwner(bytes32 node, bytes32 label, address owner) external returns(bytes32);
    function setResolver(bytes32 node, address resolver) external;
    function setOwner(bytes32 node, address owner) external;
    function setTTL(bytes32 node, uint64 ttl) external;
    function setApprovalForAll(address operator, bool approved) external;
    function owner(bytes32 node) external view returns (address);
    function resolver(bytes32 node) external view returns (address);
    function ttl(bytes32 node) external view returns (uint64);
    function recordExists(bytes32 node) external view returns (bool);
    function isApprovedForAll(address owner, address operator) external view returns (bool);
}




pragma solidity ^0.5.0;

contract ResolverBase {
    bytes4 private constant INTERFACE_META_ID = 0x01ffc9a7;

    function supportsInterface(bytes4 interfaceID) public pure returns(bool) {
        return interfaceID == INTERFACE_META_ID;
    }

    function isAuthorised(bytes32 node) internal view returns(bool);

    modifier authorised(bytes32 node) {
        require(isAuthorised(node));
        _;
    }

}


contract TextResolver is ResolverBase {
    bytes4 constant private TEXT_INTERFACE_ID = 0x59d1d43c;

    event TextChanged(bytes32 indexed node, string indexed indexedKey, string key);

    mapping(bytes32=>mapping(string=>string)) texts;

    function setText(bytes32 node, string calldata key, string calldata value) external authorised(node) {
        texts[node][key] = value;
        emit TextChanged(node, key, key);
    }
    
    function text(bytes32 node, string calldata key) external view returns (string memory) {
        return texts[node][key];
    }

    function supportsInterface(bytes4 interfaceID) public pure returns(bool) {
        return interfaceID == TEXT_INTERFACE_ID || super.supportsInterface(interfaceID);
    }
}




pragma solidity ^0.5.0;
pragma experimental ABIEncoderV2;

contract PublicResolver is TextResolver {
    
    ENS ens;


    mapping(bytes32=>mapping(address=>mapping(address=>bool))) public authorisations;

    event AuthorisationChanged(bytes32 indexed node, address indexed owner, address indexed target, bool isAuthorised);

    constructor(ENS _ens) public {
        ens = _ens;
    }


    function setAuthorisation(bytes32 node, address target, bool isAuthorised) external {
        authorisations[node][msg.sender][target] = isAuthorised;
        emit AuthorisationChanged(node, msg.sender, target, isAuthorised);
    }

    function isAuthorised(bytes32 node) internal view returns(bool) {
        address owner = ens.owner(node);
        return owner == msg.sender || authorisations[node][owner][msg.sender];
    }

    function multicall(bytes[] calldata data) external returns(bytes[] memory results) {
        results = new bytes[](data.length);
        for(uint i = 0; i < data.length; i++) {
            (bool success, bytes memory result) = address(this).delegatecall(data[i]);
            require(success);
            results[i] = result;
        }
        return results;
    }
}