6.5 KiB
Type parameters
R
S
E
Hierarchy
ApiBase
↳ ApiRx
Implements
- ApiBaseInterface<
R,S,E>
Constructors
constructor
⊕ new ApiBase(provider?: * ApiOptions | ProviderInterface*): ApiBase
Defined in Base.ts:40
description: Create an instance of the class
example:
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 |
{} |
Returns: ApiBase
Accessors
genesisHash
getgenesisHash(): Hash
Defined in Base.ts:79
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:88
description: true when subscriptions are supported
Returns: boolean
query
getquery(): S
Defined in Base.ts:124
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: S
rpc
getrpc(): R
Defined in Base.ts:144
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: R
runtimeMetadata
getruntimeMetadata(): RuntimeMetadata
Defined in Base.ts:95
description: Yields the current attached runtime metadata. Generally this is only used to construct extrinsics & storage, but is useful for current runtime inspection.
Returns: RuntimeMetadata
runtimeVersion
getruntimeVersion(): RuntimeVersion
Defined in Base.ts:104
description: Contains the version information for the current runtime.
Returns: RuntimeVersion
tx
gettx(): E
Defined in Base.ts:163
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>)
.sign(<keyPair>, <accountNonce>, <blockHash (optional)>)
.send((status) => {
console.log('tx status', status);
});
Returns: E
Methods
on
▸ on(type: ApiInterface$Events, handler: function): this
Defined in Base.ts:188
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:212
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