@polkadot/react-query/BlockAuthors.js

A collection of RxJs React components the Polkadot JS API

"use strict";

var _interopRequireWildcard = require("@babel/runtime/helpers/interopRequireWildcard");

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.BlockAuthors = BlockAuthors;
exports.ValidatorsContext = exports.BlockAuthorsContext = void 0;

var _react = _interopRequireWildcard(require("react"));

var _reactHooks = require("@polkadot/react-hooks");

var _util = require("@polkadot/util");

// Copyright 2017-2020 @polkadot/react-query authors & contributors
// This software may be modified and distributed under the terms
// of the Apache-2.0 license. See the LICENSE file for details.
const MAX_HEADERS = 25;
const byAuthor = {};

const BlockAuthorsContext = _react.default.createContext({
  byAuthor,
  lastHeaders: []
});

exports.BlockAuthorsContext = BlockAuthorsContext;

const ValidatorsContext = _react.default.createContext([]);

exports.ValidatorsContext = ValidatorsContext;

function BlockAuthors({
  children
}) {
  const {
    api
  } = (0, _reactHooks.useApi)();
  const [state, setState] = (0, _react.useState)({
    byAuthor,
    lastHeaders: []
  });
  const [validators, setValidators] = (0, _react.useState)([]);
  (0, _react.useEffect)(() => {
    // TODO We should really unsub - but since this should just be used once,
    // atm I'm rather typing this than doing it the way it is supposed to be
    api.isReady.then(() => {
      let lastHeaders = [];
      let lastBlockAuthors = [];
      let lastBlockNumber = ''; // subscribe to all validators

      api.query.session && api.query.session.validators(validatorIds => {
        setValidators(validatorIds.map(validatorId => validatorId.toString()));
      }); // subscribe to new headers

      api.derive.chain.subscribeNewHeads(lastHeader => {
        if (lastHeader === null || lastHeader === void 0 ? void 0 : lastHeader.number) {
          var _lastHeader$author;

          const blockNumber = lastHeader.number.unwrap();
          const thisBlockAuthor = (_lastHeader$author = lastHeader.author) === null || _lastHeader$author === void 0 ? void 0 : _lastHeader$author.toString();
          const thisBlockNumber = (0, _util.formatNumber)(blockNumber);

          if (thisBlockAuthor) {
            byAuthor[thisBlockAuthor] = thisBlockNumber;

            if (thisBlockNumber !== lastBlockNumber) {
              lastBlockNumber = thisBlockNumber;
              lastBlockAuthors = [thisBlockAuthor];
            } else {
              lastBlockAuthors.push(thisBlockAuthor);
            }
          }

          lastHeaders = lastHeaders.filter((old, index) => index < MAX_HEADERS && old.number.unwrap().lt(blockNumber)).reduce((next, header) => {
            next.push(header);
            return next;
          }, [lastHeader]).sort((a, b) => b.number.unwrap().cmp(a.number.unwrap()));
          setState({
            byAuthor,
            lastBlockAuthors: lastBlockAuthors.slice(),
            lastBlockNumber,
            lastHeader,
            lastHeaders
          });
        }
      });
    });
  }, []);
  return _react.default.createElement(ValidatorsContext.Provider, {
    value: validators
  }, _react.default.createElement(BlockAuthorsContext.Provider, {
    value: state
  }, children));
}