RNS JS Library - Utils
Available methods
isValidDomain
Validates the given domain syntax. It allows dots and alphanumeric lowercase characters.
Signature
isValidDomain(domain:string): boolean;Parameters
domain: Domain to be validated.
Returns
bool: true if valid, false if not
Examples
Valid domain:
rns.utils.isValidDomain('testing123.rsk').then(console.log)Invalid domain:
rns.utils.isValidDomain('nOtVali-d.rsk').then(console.log)isValidLabel
Validates the given label syntax. It allows alphanumeric lowercase characters.
Signature
isValidLabel(label:string): boolean;Parameters
label: Label to be validated.
Returns
bool: true if valid, false if not
Examples
Valid label:
rns.utils.isValidLabel('testing123').then(console.log)Invalid label:
rns.utils.isValidLabel('no%tvAl1d').then(console.log)isValidTld
Validates the given top level domain. For now, the only valid TLD is rsk
Signature
isValidTld(tld:string): boolean;Parameters
tld: TLD to be validated.
Returns
bool: true if valid, false if not
Examples
Valid TLD:
rns.utils.isValidTld('rsk').then(console.log)Invalid TLD:
rns.utils.isValidTld('notvalid').then(console.log)namehash
Returns the namehash representation of the given domain
Signature
namehash(domain:string): boolean;Parameters
domain: Domain to be converted.
Returns
string: Namehash representation of the given domain
Examples
rns.utils.namehash('testing.rsk').then(console.log)labelhash
Returns 0x + the keccak256 representation of the given label.
Signature
labelhash(label:string): boolean;Parameters
label: Label to be converted.
Returns
string: Labelhash representation of the given domain
Examples
rns.utils.labelhash('testing').then(console.log)hasAccounts
Checks if the given web3 instance has accounts to sign transactions
Signature
hasAccounts(web3:Web3): boolean;Parameters
web3: Web3 instance.
Returns
bool: true if has accounts, false if not
Examples
const web3 = new Web3('https://public-node.rsk.co');
rns.utils.hasAccounts(web3).then(console.log)hasMethod
Checks if the contract in the given address has the given method
Signature
hasMethod(web3:Web3, contractAddress:string, methodId: string): boolean;Parameters
web3: Web3 instance.contractAddress: address of the contract to check.methodId: the first 4 bytes of the keccak256 hash of the ASCII form of the signature
How to obtain the methodId?
Given the following Solidity function
function max(uint256 a, uint256 b) internal pure returns (uint256) { return a >= b ? a : b; }
> The signature is `max(uint256,uint256)`.
>
> The methodId is calculated with this Javascript function:
>
>```javascript
function getMethodId(signature) {
const hash = keccak256(signature);
return `0x${hash.substring(0, 8)}`;
}Returns
bool: true if has method, false if not
Examples
const web3 = new Web3('https://public-node.rsk.co');
const address = '0x0000000000000000000000000000000000000001';
const methodHash = '0x01ffc9a7';
rns.utils.hasMethod(web3, contractAddress, methodHash).then(console.log)