Amaury Martiny
16e0ea9315
* Move Metadata to api-metadata * Make tests in api-metadata pass * Make tests in api-metadata pass * Refactor fromMetadata into decorated * Fix some linting * Replace headers * Fix all tests * Small lint * Fix tests * Fix metadata docs scripts * Fix import ordering * Add line breaks * Grumbles * Fix forgotten import * rpcMetadata everywhere * Fixlint * s/api-metadata/metadata * Fix latest tests * Fix lint * Fix tests
@polkadot/rpc-provider
Generic transport providers to handle the transport of method calls to and from Polkadot clients from applications interacting with it. It provides an interface to making RPC calls and is generally, unless you are operating at a low-level and taking care of encoding and decoding of parameters/results, it won't be directly used, rather only passed to a higher-level interface.
Provider Selection
There are two flavours of the providers provided, one allowing for using HTTP as a transport mechanism, the other using WebSockets. It is generally recommended to use the WsProvider since in addition to standard calls, it allows for subscriptions where all changes to state can be pushed from the node to the client.
Both providers are usable (as is the API), in both browser-based and Node.js environments. Polyfills for unsupported functionality are automatically applied based on feature-detection.
Usage
Installation -
yarn add @polkadot/rpc-provider
WebSocket Initialisation -
import WsProvider from '@polkadot/rpc-provider/ws';
// this is the actual default endpoint
const provider = new WsProvider('ws://127.0.0.1:9944');
const version = await provider.send('client_version', []);
console.log('client version', version);
HTTP Initialisation -
import { HttpProvider } from '@polkadot/rpc-provider';
// this is the actual default endpoint
const provider = new HttpProvider('http://127.0.0.1:9933');
const version = await provider.send('chain_getBlockHash', []);
console.log('latest block Hash', hash);