Axel Chalon
9abbaab991
* @polkadot/{extrinsics,storage} moved to @polkadot/metadata
* Fix previous commit
* Fix previous commit
* Expose parameter types using api.consts
* Grumbles; update v6 static metadata; add UncleEntryItem (fix #1067)
* Update api.query.* to api.consts.* where changed
* Update tests and stray api.query.staking.sessionsPerEra
* Grumbles
* Grumbles
* Revert updates to api-derive (taken care of by #1068)
* Grumbles; fix UncleEntryItem
* Rename "@polkadot/metadata" => "@polkadot/api-metadata"
* Skip derive test
* Grumbles
* Grumbles
* Grumbles
* Cleanup merge, ensure metadata is latest
* Move api-metadata to actual api-metadata folder
* README api-metadata description (& folder link)
* Remove stray type-extrinsics package.json
@polkadot/rpc-core
This library provides a clean wrapper around all the methods exposed by a Polkadot network client.
Usage
Installation -
yarn add @polkadot/rpc-core
Initialisation -
import Rpc from '@polkadot/rpc-core';
import WsProvider from '@polkadot/rpc-provider/ws';
const provider = new WsProvider('http://127.0.0.1:9944');
const rpc = new Rpc(provider);
Retrieving the block header object for a given block header hash (a 0x-prefixed hex string with length of 64) -
rpc.chain
.getHeader('0x1234567890')
.subscribe(
(header) => console.log(header),
(error) => console.error('error:', error)
);
Retrieving the best block number, parent hash, state root hash, extrinsics root hash, and digest (once-off) -
rpc.chain
.getHead()
.pipe(
switchMap((headerHash) => {
return rpc.chain.getHeader(headerHash);
})
)
.subscribe(
(header) => {
console.log(`best #${header.blockNumber.toString()}`);
console.log(`parentHash: ${header.parentHash.toString()}`);
console.log(`stateRoot: ${header.stateRoot.toString()}`);
console.log(`extrinsicsRoot: ${header.extrinsicsRoot.toString()}`);
console.log(`digest: ${header.digest.toString()}`);
},
(error) => {
console.error('error:', error);
}
);
Retrieving best header via subscription -
api.chain
rpc
.subscribeNewHead()
.subscribe(
(header) => {
console.log(`best #${header.blockNumber}`);
},
(error) => {
console.error('error subscribing:', error);
}
);