70 lines
2.3 KiB
TypeScript
70 lines
2.3 KiB
TypeScript
// Copyright 2017-2019 @polkadot/api-derive authors & contributors
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// This software may be modified and distributed under the terms
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// of the Apache-2.0 license. See the LICENSE file for details.
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import { ApiInterfaceRx } from '@polkadot/api/types';
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import { Balance } from '@polkadot/types/interfaces';
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import { DerivedFees } from '../types';
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import { Observable, of } from 'rxjs';
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import { map } from 'rxjs/operators';
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import { memo } from '../util';
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type Result = [Balance, Balance, Balance, Balance, Balance];
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function queryV2 (api: ApiInterfaceRx): Observable<Result> {
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const paymentBase = api.consts.transactionPayment || api.consts.balances;
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return of([
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// get values from api.const for substrate versions post spec_version: 101
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// https://github.com/paritytech/substrate/pull/2883/files#diff-5e5e1c3aec9ddfde0a9054d062ab3db9R131
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api.consts.balances.creationFee as Balance,
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api.consts.balances.existentialDeposit as Balance,
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api.consts.balances.transferFee as Balance,
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paymentBase.transactionBaseFee as Balance,
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paymentBase.transactionByteFee as Balance
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]);
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}
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function queryV1 (api: ApiInterfaceRx): Observable<Result> {
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return api.queryMulti<Result>([
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// Support older versions and get values from storage
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api.query.balances.creationFee,
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api.query.balances.existentialDeposit,
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api.query.balances.transferFee,
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api.query.balances.transactionBaseFee,
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api.query.balances.transactionByteFee
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]);
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}
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/**
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* @name fees
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* @returns An object containing the combined results of the storage queries for
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* all relevant fees as declared in the substrate chain spec.
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* @example
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* <BR>
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*
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* ```javascript
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* api.derive.balances.fees(({ creationFee, transferFee }) => {
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* console.log(`The fee for creating a new account on this chain is ${creationFee} units. The fee required for making a transfer is ${transferFee} units.`);
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* });
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* ```
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*/
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export function fees (api: ApiInterfaceRx): () => Observable<DerivedFees> {
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const query = api.consts.balances
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? queryV2
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: queryV1;
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return memo((): Observable<DerivedFees> =>
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query(api).pipe(
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map(([creationFee, existentialDeposit, transferFee, transactionBaseFee, transactionByteFee]): DerivedFees => ({
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creationFee,
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existentialDeposit,
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transactionBaseFee,
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transactionByteFee,
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transferFee
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}))
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));
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}
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