Files
api/packages/api-derive/src/staking/validators.ts
T
Valentin Fernandez ed62d164ea Document available Api Derives (#6106)
* document derives from accounts to democracy

* Derive Documentation progress

* Derive Documentation progress

* tx and staking docs

* Staking docs progress

* more staking docs

* Staking module complete

* imonline, elections and progress in democracy

* Document missing derives

* lint
2025-02-27 10:56:34 -03:00

83 lines
3.3 KiB
TypeScript

// Copyright 2017-2025 @polkadot/api-derive authors & contributors
// SPDX-License-Identifier: Apache-2.0
import type { Observable } from 'rxjs';
import type { AccountId } from '@polkadot/types/interfaces';
import type { DeriveApi, DeriveStakingValidators } from '../types.js';
import { combineLatest, map, of, switchMap } from 'rxjs';
import { memo } from '../util/index.js';
/**
* @name nextElected
* @description Retrieves the list of accounts that are set to be the next elected validators in the staking system. It provides a preview of who will be validators in the next staking era.
* @example
* ```javascript
* const nextElected = await api.derive.staking.nextElected();
* console.log(
* "Next Elected Validators:",
* nextElected.map((acc) => acc.toString())
* );
* ```
*/
export function nextElected (instanceId: string, api: DeriveApi): () => Observable<AccountId[]> {
return memo(instanceId, (): Observable<AccountId[]> =>
// Compatibility for future generation changes in staking.
api.query.staking.erasStakersOverview
? api.derive.session.indexes().pipe(
// only populate for next era in the last session, so track both here - entries are not
// subscriptions, so we need a trigger - currentIndex acts as that trigger to refresh
switchMap(({ currentEra }) => api.query.staking.erasStakersOverview.keys(currentEra)),
// Dedupe any duplicates
map((keys) => [...new Set(keys.map(({ args: [, accountId] }) => accountId.toString()))].map((a) => api.registry.createType('AccountId', a)))
)
: api.query.staking.erasStakers
? api.derive.session.indexes().pipe(
// only populate for next era in the last session, so track both here - entries are not
// subscriptions, so we need a trigger - currentIndex acts as that trigger to refresh
switchMap(({ currentEra }) => api.query.staking.erasStakers.keys(currentEra)),
// Dedupe any duplicates
map((keys) => [...new Set(keys.map(({ args: [, accountId] }) => accountId.toString()))].map((a) => api.registry.createType('AccountId', a)))
)
: api.query.staking['currentElected']<AccountId[]>()
);
}
/**
* @name validators
* @description Retrieve latest list of validators.
* @example
* ```javascript
* const { validators, nextElected } = await api.derive.staking.validators();
* console.log(
* "Current Validators:",
* validators.map((v) => v.toString())
* );
* console.log(
* "Next Elected Validators:",
* nextElected.map((v) => v.toString())
* );
* ```
*/
export function validators (instanceId: string, api: DeriveApi): () => Observable<DeriveStakingValidators> {
return memo(instanceId, (): Observable<DeriveStakingValidators> =>
// Sadly the node-template is (for some obscure reason) not comprehensive, so while the derive works
// in all actual real-world deployed chains, it does create some confusion for limited template chains
combineLatest([
api.query.session
? api.query.session.validators()
: of([]),
api.query.staking
? api.derive.staking.nextElected()
: of([])
]).pipe(
map(([validators, nextElected]): DeriveStakingValidators => ({
nextElected: nextElected.length
? nextElected
: validators,
validators
}))
));
}