import Api from '@polkadot/api/promise';

const api = new Api().isReady();

api.rpc.subscribeNewHead((header) => {
  console.log(`new block #${header.blockNumber.toNumber()}`);
});

Parameters:

Name	Type	Default value
`Default value` provider	ApiOptions \| `ProviderInterface`	{}
type	ApiType	-

Returns: ApiBase

Accessors

derive

getderive(): Derive<CodecResult, SubscriptionResult>

Defined in Base.ts:196

description: Derived results that are injected into the API, allowing for combinations of various query results.

example:

api.derive.chain.bestNumber((number) => {
  console.log('best number', number);
});

Returns: Derive<CodecResult, SubscriptionResult>

genesisHash

getgenesisHash(): Hash

Defined in Base.ts:132

description: Contains the genesis Hash of the attached chain. Apart from being useful to determine the actual chain, it can also be used to sign immortal transactions.

Returns: Hash

hasSubscriptions

gethasSubscriptions(): boolean

Defined in Base.ts:141

description: true when subscriptions are supported

Returns: boolean

libraryInfo

getlibraryInfo(): string

Defined in Base.ts:148

description: The library information name & version (from package.json)

Returns: string

query

getquery(): QueryableStorage<CodecResult, SubscriptionResult>

Defined in Base.ts:216

description: Contains all the chain state modules and their subsequent methods in the API. These are attached dynamically from the runtime metadata.

All calls inside the namespace, is denoted by section.method and may take an optional query parameter. As an example, api.query.timestamp.now() (current block timestamp) does not take parameters, while api.query.system.accountNonce(<accountId>) (retrieving the associated nonce for an account), takes the AccountId as a parameter.

example:

api.query.balances.freeBalance(<accountId>, (balance) => {
  console.log('new balance', balance);
});

Returns: QueryableStorage<CodecResult, SubscriptionResult>

rpc

getrpc(): DecoratedRpc<CodecResult, SubscriptionResult>

Defined in Base.ts:236

description: Contains all the raw rpc sections and their subsequent methods in the API as defined by the jsonrpc interface definitions. Unlike the dynamic api.query and api.tx sections, these methods are fixed (although extensible with node upgrades) and not determined by the runtime.

RPC endpoints available here allow for the query of chain, node and system information, in addition to providing interfaces for the raw queries of state (usine known keys) and the submission of transactions.

example:

api.rpc.chain.subscribeNewHead((header) => {
  console.log('new header', header);
});

Returns: DecoratedRpc<CodecResult, SubscriptionResult>

runtimeMetadata

getruntimeMetadata(): Metadata

Defined in Base.ts:155

description: Yields the current attached runtime metadata. Generally this is only used to construct extrinsics & storage, but is useful for current runtime inspection.

Returns: Metadata

runtimeVersion

getruntimeVersion(): RuntimeVersion

Defined in Base.ts:164

description: Contains the version information for the current runtime.

Returns: RuntimeVersion

tx

gettx(): SubmittableExtrinsics<CodecResult, SubscriptionResult>

Defined in Base.ts:254

description: Contains all the extrinsic modules and their subsequent methods in the API. It allows for the construction of transactions and the submission thereof. These are attached dynamically from the runtime metadata.

example:

api.tx.balances
  .transfer(<recipientId>, <balance>)
  .signAndSend(<keyPair>, ({status}) => {
    console.log('tx status', status.asFinalised.toHex());
  });

Returns: SubmittableExtrinsics<CodecResult, SubscriptionResult>

type

gettype(): ApiType

Defined in Base.ts:173

description: The type of this API instance, either 'rxjs' or 'promise'

Returns: ApiType

Methods

disconnect

▸ disconnect(): void

Defined in Base.ts:263

description: Disconnect from the underlying provider, halting all comms

Returns: void

on

▸ on(type: ApiInterface$Events, handler: function): this

Defined in Base.ts:286

description: Attach an eventemitter handler to listen to a specific event

example:

api.on('connected', () => {
  console.log('API has been connected to the endpoint');
});

api.on('disconnected', () => {
  console.log('API has been disconnected from the endpoint');
});

Parameters:

Name	Type	Description
type	ApiInterface$Events	The type of event to listen to. Available events are `connected`, `disconnected`, `ready` and `error`
handler	`function`	The callback to be called when the event fires. Depending on the event type, it could fire with additional arguments.

Returns: this

once

▸ once(type: ApiInterface$Events, handler: function): this

Defined in Base.ts:311

description: Attach an one-time eventemitter handler to listen to a specific event

example:

api.once('connected', () => {
  console.log('API has been connected to the endpoint');
});

api.once('disconnected', () => {
  console.log('API has been disconnected from the endpoint');
});

Parameters:

Name	Type	Description
type	ApiInterface$Events	The type of event to listen to. Available events are `connected`, `disconnected`, `ready` and `error`
handler	`function`	The callback to be called when the event fires. Depending on the event type, it could fire with additional arguments.

Returns: this

registerTypes

▸ registerTypes(types?: RegistryTypes): void

Defined in Base.ts:320

description: Register additional user-defined of chain-specific types in the type registry

Parameters:

Name	Type
`Optional` types	`RegistryTypes`

Returns: void

setSigner

▸ setSigner(signer: Signer): void

Defined in Base.ts:180

description: Set an external signer which will be used to sign extrinsic when account passed in is not KeyringPair

Parameters:

Name	Type
signer	Signer

Returns: void

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Type parameters

CodecResult

SubscriptionResult

Hierarchy

Implements

Constructors

constructor

Accessors

derive

genesisHash

hasSubscriptions

libraryInfo

query

rpc

runtimeMetadata

runtimeVersion

tx

type

Methods

disconnect

on

once

registerTypes

setSigner

9.7 KiB

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