Considering rank service at server side

[shingonu]

before user sign in, we can get all the accounts that have power. but after user sign in, vapp can't detect event for other user's deposit.

so we have to consider to make rank service at server side.

[shingonu]

have to make event listener

[shingonu]

myContract.events.MyEvent([options][, callback]) doesn't work.

const sub = this.DepositManager.events.Deposited({
  fromBlock: this.blockNumber,
}, function (error, event){
  console.log(event);
})
  .on('data', function (event){
    console.log(event); // same results as the optional callback above
  })
  .on('changed', function (event){
    // remove event from local database
  })
  .on('error', console.error);

[shingonu]

also not working

const subscription = this.web3.eth.subscribe('logs', {
  address: this.DepositManager._address,
}, function (error, result){
  if (error)
    console.log('error', error);
  console.log('result', result);
});

[shingonu]

it works: this.web3.currentProvider.on('data', console.log);

make rootchain blocktime 10 seconds. otherwise we can meet this error again.

[shingonu]

reference: MetaMask/metamask-extension#5458

[shingonu]

after block time set 10s, all event listeners work.

so we use this one.

this.DepositManager.events.Deposited({
  fromBlock: this.blockNumber,
}, function (error, event){
  console.log(event);
})
  .on('data', function (event){
    console.log(event); // same results as the optional callback above
  })
  .on('changed', function (event){
    // remove event from local database
  })
  .on('error', console.error);

[shingonu]

Klaytn..? 1s?

[shingonu]

unsubscribe event listener

• reference: Unsubscribe from listening to events in web3 1.0 web3/web3.js#1587

[shingonu]

we need to check subscribe function, when same deposited function called under other circumstance.

[shingonu]

before sign in:

async setAccountsDepositedWithPower (context) {
  const web3 = context.state.web3;
  const PowerTON = context.state.PowerTON;
  const DepositManager = context.state.DepositManager;

  const depositedEvent = web3.eth.abi.encodeEventSignature('Deposited(address,address,uint256)');
  const deployedAt = DepositManager.transactionConfirmationBlocks;

  // event Deposited(address indexed rootchain, address depositor, uint256 amount);
  const events = await DepositManager.getPastEvents('Deposited', {
    fromBlock: deployedAt,
    toBlock: 'latest',
    topics: [depositedEvent],
  });

  const depositors = uniq(events.map(event => event.returnValues.depositor));
  const accounts = depositors.map(async depositor => {
    const power = await PowerTON.methods.powerOf(depositor).call();
    return {
      address: depositor.toLowerCase(),
      power: _POWER.ray(power.toString()),
    };
  });
  context.commit('SET_ACCOUNTS_DEPOSITED_WITH_POWER', await Promise.all(accounts));
},

after sign in:

async subscribe () {
  this.depositedEventSubscription = this.DepositManager.events.Deposited({
    fromBlock: 'latest',
  }, async (error, event) => {
    if (error) {
      //
    }
    const result = event.returnValues;
    this.$store.dispatch('addAccountDepositedWithPower', result.depositor);
  });
},

async addAccountDepositedWithPower (context, depositor) {
  const PowerTON = context.state.PowerTON;
  const power = await PowerTON.methods.powerOf(depositor).call();
  context.commit('ADD_ACCOUNT_DEPOSITED_WITH_POWER', {
    address: depositor.toLowerCase(),
    power: _POWER.ray(power.toString()),
  });

ADD_ACCOUNT_DEPOSITED_WITH_POWER: (state, accountWithPower) => {
  const findAccount = (account) => account.address.toLowerCase() === accountWithPower.address.toLowerCase();
  const index = state.accountsDepositedWithPower.findIndex(findAccount);

  if (index > -1) {
    Vue.set(state.accountsDepositedWithPower, index, accountWithPower);
  } else {
    state.accountsDepositedWithPower.push(accountWithPower);
  }
},