144 lines
5.2 KiB
Markdown
144 lines
5.2 KiB
Markdown
|
|
# Javascript Library
|
|
|
|
To simplify the process of building the whisper messages, a js file `status-gas-relayer.js` was created in the test-dapp. It only requires to setup connection to geth, and required keypairs and symkeys. This file might be expanded upon in the future and converted to a npm package.
|
|
|
|
## Use
|
|
|
|
```
|
|
import StatusGasRelayer, {Contracts, Functions, Messages} from 'status-gas-relayer';
|
|
|
|
// Connecting to web3
|
|
const web3 = new Web3('ws://localhost:8546');
|
|
const kid = await web3js.shh.newKeyPair()
|
|
const skid = await web3.shh.addSymKey("0xd0d905c1c62b810b787141430417caf2b3f54cffadb395b7bb39fdeb8f17266b");
|
|
```
|
|
|
|
#### Subscribing to messages
|
|
General message subscription. Special handling is needed for handling relayer availability messages. The `sig` property is the relayer's public key that needs to be sent when sending a transaction message. More than 1 relayer can reply, so it's recommended to save these keys in a list/array.
|
|
|
|
```
|
|
StatusGasRelayer.subscribe(web3js, (error, msgObj) => {
|
|
if(error) {
|
|
console.error(error);
|
|
return;
|
|
}
|
|
|
|
if(msgObj.message == Messages.available){
|
|
// Relayer availability message
|
|
console.log("Relayer available: " + msgObj.sig);
|
|
} else {
|
|
// Normal message
|
|
console.log(msgObj);
|
|
}
|
|
}, {
|
|
privateKeyID: kid
|
|
});
|
|
```
|
|
|
|
#### Polling for relayers
|
|
```
|
|
const identityAddress = this.props.identityAddress; // Identity contract
|
|
const accountAddress = web3.eth.defaultAccount;
|
|
const gasToken = SNT.options.address;
|
|
const gasPrice = 1000000000000; // In wei equivalent to the used token
|
|
|
|
const s = new StatusGasRelayer.AvailableRelayers(Contracts.Identity, identityAddress, accountAddress)
|
|
.setRelayersSymKeyID(skid)
|
|
.setAsymmetricKeyID(kid)
|
|
.setGasToken(gasToken)
|
|
.setGas(gasPrice);
|
|
await s.post(web3);
|
|
```
|
|
|
|
#### Signing a message
|
|
Signing a message is similar to invoking a function. Both use mostly the same functions. The difference is that when you invoke a function, you need to specify the relayer and asymmetric key Id.
|
|
|
|
```
|
|
try {
|
|
const s = new StatusGasRelayer.Identity(identityAddress, accountAddress)
|
|
.setContractFunction(Functions.Identity.call)
|
|
.setTransaction(to, value, data)
|
|
.setGas(gasToken, gasPrice, gasLimit);
|
|
|
|
const signature = await s.sign(web3);
|
|
} catch(error){
|
|
console.log(error);
|
|
}
|
|
|
|
```
|
|
|
|
#### Using Identity contract `call` function
|
|
This functionality is used when a Identity will invoke a contract function or transfer ether without paying fees
|
|
|
|
```
|
|
try {
|
|
const s = new StatusGasRelayer.Identity(identityAddress, accountAddress)
|
|
.setContractFunction(Functions.Identity.call)
|
|
.setTransaction(to, value, data) // 'value' is in wei, and 'data' must be a hex string
|
|
.setGasToken(gasToken)
|
|
.setGas(gasPrice, gasMinimal)
|
|
.setRelayer(relayer)
|
|
.setAsymmetricKeyID(kid);
|
|
|
|
await s.post(signature, web3);
|
|
} catch(error){
|
|
console.log(error);
|
|
}
|
|
```
|
|
|
|
#### Using Identity contract `approveAndCall` function
|
|
This functionality is used when a Identity will invoke a contract function that requires a transfer of Tokens
|
|
|
|
```
|
|
try {
|
|
const s = new StatusGasRelayer.Identity(identityAddress, accountAddress)
|
|
.setContractFunction(Functions.Identity.approveAndCall)
|
|
.setTransaction(to, value, data)
|
|
.setBaseToken(baseToken)
|
|
.setGas(gasPrice, gasMinimal)
|
|
.setGasToken(SNT_Address)
|
|
.setRelayer(relayer)
|
|
.setAsymmetricKeyID(kid);
|
|
|
|
await s.post(signature, web3);
|
|
} catch(error){
|
|
console.log(error);
|
|
}
|
|
```
|
|
|
|
#### Using SNTController `transferSNT` function
|
|
This functionality is used for simple wallets to perform SNT transfers without paying ETH fees
|
|
```
|
|
try {
|
|
const accounts = await web3.eth.getAccounts();
|
|
|
|
const s = new StatusGasRelayer.SNTController(SNTController.options.address, accounts[2])
|
|
.transferSNT(to, amount)
|
|
.setGas(gasPrice)
|
|
.setRelayer(relayer)
|
|
.setAsymmetricKeyID(kid);
|
|
|
|
await s.post(signature, web3);
|
|
} catch(error){
|
|
console.log(error);
|
|
}
|
|
```
|
|
|
|
#### Using SNTController `execute` function
|
|
```
|
|
try {
|
|
const accounts = await web3.eth.getAccounts();
|
|
|
|
const s = new StatusGasRelayer.SNTController(SNTController.options.address, accounts[2])
|
|
.execute(allowedContract, data)
|
|
.setGas(gasPrice, gasMinimal)
|
|
.setRelayer(relayer)
|
|
.setAsymmetricKeyID(kid);
|
|
|
|
await s.post(signature, web3);
|
|
} catch(error){
|
|
console.log(error);
|
|
}
|
|
```
|