updateOracle

The updateOracle method serves to refresh an existing oracle with the latest data fetched from the linked API. This ensures that the oracle maintains up-to-date information, enhancing its reliability and usefulness for downstream applications.

Usage

As an example, we will utilize the CoinGecko public API oracle, which provides the Ethereum price in USD: CoinGecko Ethereum API.

// create an observable
const updateOracleObservable = factory.updateOracle(
  {
    JSONPath: "$['ethereum']['usd']",
    body: '',
    dataType: 'number',
    dataset: '0x0000000000000000000000000000000000000000',
    headers: {},
    method: 'GET',
    url: 'https://api.coingecko.com/api/v3/simple/price?ids=ethereum&vs_currencies=usd',
  },
  {
    workerpool: '0xa5de76...',
    targetBlockchains: [137],
  }
);

// subscribe to the observable and start the workflow
updateOracleObservable.subscribe({
  next: (data) => {
    console.log('next', data);
  },
  error: (error) => {
    console.log('error', error);
  },
  complete: () => {
    console.log('Oracle update Completed');
  },
});

Parameters

paramSet or paramSetCid Required *

TIP

• The oracle ParamSet describes the parameters used to feed the oracle.

• Any different ParamSet has a unique ParamSetCid which is the Content ID of the document on IPFS. With a ParamSetCid anyone can retrieve the ParamSet from IPFS.

• ParamSet of the Oracle to update.

const paramSet: ParamSet = { 
  JSONPath: "$['ethereum']['usd']",
  body: '',
  dataType: 'number',
  dataset: '0x0000000000000000000000000000000000000000',
  headers: {},
  method: 'GET',
  url: 'https://api.coingecko.com/api/v3/simple/price?ids=ethereum&vs_currencies=usd',
};

const updateOracleObservable = factory.updateOracle(
  paramSet
);

• ParamSet CID of the Oracle to update.

const paramSetCid: ParamSetCID =
  'QmbeY27w6dKxNQnGXih4AaotgNY3XuZ2yzbi2ZWQfRApqs';

const updateOracleObservable = factory.updateOracle(
  paramSetCid
);

useVoucher Optional

Type: boolean
Default: false

This optional param allows you to pay for the deal using your voucher. Make sure that your voucher is held by your connected wallet.

import { IExecOracleFactory } from '@iexec/iexec-oracle-factory-wrapper';
const web3Provider = {} as any;
const factory = new IExecOracleFactory(web3Provider);

// ---cut---
const updateOracleObservable = factory.updateOracle(
  {
    JSONPath: "$['ethereum']['usd']",
    body: '',
    dataType: 'number',
    dataset: '0x0000000000000000000000000000000000000000',
    headers: {},
    method: 'GET',
    url: 'https://api.coingecko.com/api/v3/simple/price?ids=ethereum&vs_currencies=usd',
  },
  {
    useVoucher: true,
  }
);

TIP

If your voucher doesn't have enough xRLC to cover the deal, the SDK will automatically get the required amount to your iExec account. Ensure that your voucher is authorized to access your iExec account and that your account has sufficient funds for this transfer to proceed.

workerpool Optional

Address of the workerpool that should perform the update.

const updateOracleObservable = factory.updateOracle(
  'QmbXhtjAJysMMA69KkB8KohsEDTZA2PXuhYdAQcHjjQFit',
  {
    workerpool: '0xa5de76...',
    targetBlockchains: [137],
  }
);

TIP

iExec currently offers a production workerpool located at the Ethereum Name Service (ENS) address prod-v8-bellecour.main.pools.iexec.eth. This is the default workerpool for running confidential computations on the iExec platform.

targetBlockchains Optional

Array of target blockchain chainId where the oracle is deployed. 1 for Ethereum mainnet, 137 for Polygon mainnet.

const updateOracleObservable = factory.updateOracle(
  'QmbXhtjAJysMMA69KkB8KohsEDTZA2PXuhYdAQcHjjQFit',
  {
    workerpool: '0xa5de76...',
    targetBlockchains: [1, 137],
  }
);

Return value

Observable<UpdateOracleMessage>

import type {
  UpdateOracleMessage, // any `data` the `next(data)` handler can receive

  // all `data` types
  EnsureParamsMessage, // check ParamSet can be found on IPFS
  EnsureParamsUploadMessage, // the ParamSet will be uploaded on IPFS
  EnsureParamsSuccessMessage, // ParamSet exists on IPFS
  FetchAppOrderMessage, // fetching app order
  FetchAppOrderSuccessMessage, // app order found
  FetchDatasetOrderMessage, // fetching dataset order (only for oracles using API key dataset)
  FetchDatasetOrderSuccessMessage, // app order found (only for oracles using API key dataset)
  FetchWorkerpoolOrderMessage, // fetching workerpool order
  FetchWorkerpoolOrderSuccessMessage, // app workerpool found
  RequestOrderSignatureSignRequestMessage, // asking the user to sign the request order
  RequestOrderSignatureSuccessMessage, //
  MatchOrdersSignTxRequestMessage, // asking the user to sign the transaction to match the orders and make a deal
  MatchOrdersSuccessMessage, // orders matched
  TaskUpdatedMessage, // notifies a task status change
  UpdateTaskCompletedMessage, // the oracle update task is completed
} from '@iexec/iexec-oracle-factory-wrapper';

TIP

Nothing happens before subscribe() is called on the returned observable.

You can provide custom next, complete and error callback methods to subscribe

// method to call when the workflow goes to a new step
const nextCallback: ObservableNext<UpdateOracleMessage> = (data) => {
  // your logic
};

// method to call when the workflow completes successfully
const completeCallback: ObservableComplete = () => {
  // your logic
};

// method to call when the workflow fails
const errorCallback: ObservableError = (error: Error) => {
  // your logic
};

updateOracleObservable.subscribe({
  next: nextCallback,
  complete: completeCallback,
  error: errorCallback,
});