Files
api/packages/api-derive/src/chain/subscribeNewBlocks.ts
T
Jaco Greeff 1c86333b5f derive.chain.getBlock() now maps events to extrinsics (#3020)
* derive.chain.getBlock() now maps events to extrinsics

* Also apply to subscribeNewBlocks

* Cleanup

* breaking
2021-01-05 12:21:58 +01:00

36 lines
1.2 KiB
TypeScript

// Copyright 2017-2021 @polkadot/api-derive authors & contributors
// SPDX-License-Identifier: Apache-2.0
import type { ApiInterfaceRx } from '@polkadot/api/types';
import type { AccountId, EventRecord, SignedBlock } from '@polkadot/types/interfaces';
import type { Observable } from '@polkadot/x-rxjs';
import { combineLatest, of } from '@polkadot/x-rxjs';
import { map, switchMap } from '@polkadot/x-rxjs/operators';
import { SignedBlockExtended } from '../type';
import { memo } from '../util';
/**
* @name subscribeNewBlocks
* @returns The latest block & events for that block
*/
export function subscribeNewBlocks (instanceId: string, api: ApiInterfaceRx): () => Observable<SignedBlockExtended> {
return memo(instanceId, (): Observable<SignedBlockExtended> =>
api.derive.chain.subscribeNewHeads().pipe(
switchMap((header): Observable<[SignedBlock, EventRecord[], AccountId[] | undefined]> => {
const blockHash = header.hash;
return combineLatest(
api.rpc.chain.getBlock(blockHash),
api.query.system.events.at(blockHash),
of(header.validators)
);
}),
map(([block, events, validators]) =>
new SignedBlockExtended(api.registry, block, events, validators)
)
)
);
}