org.polkadot.api

Class ApiBase<ApplyResult>

java.lang.Object

org.polkadot.api.ApiBase<ApplyResult>

All Implemented Interfaces:

Types.ApiBaseInterface<ApplyResult>, IApi<ApplyResult>

Direct Known Subclasses:

ApiPromise, ApiRx

public abstract class ApiBase<ApplyResult>
extends java.lang.Object
implements Types.ApiBaseInterface<ApplyResult>

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ApiBase.ApiType

Field Summary

Fields

Modifier and Type	Field and Description
protected Types.DecoratedRpc<ApplyResult>	decoratedRpc
Hash	genesisHash Contains the genesis Hash of the attached chain.
static int	KEEPALIVE_INTERVAL
protected Types.ApiOptions	options
RpcCore	rpcBase
RuntimeVersion	runtimeVersion Contains the version information for the current runtime.
Types.Signer	signer An external signer which will be used to sign extrinsic when account passed in is not KeyringPair

Constructor Summary

Constructors

Constructor and Description
ApiBase(IProvider provider, ApiBase.ApiType apiType) Create an instance of the class
ApiBase(Types.ApiOptions options, ApiBase.ApiType apiType)

Method Summary

Modifier and Type	Method and Description
protected <ApplyResult> Types.DecoratedRpc<ApplyResult>	decorateRpc(RpcCore rpcCore, Types.OnCallDefinition<ApplyResult> onCall)
Types.Derive<ApplyResult>	derive() Derived results that are injected into the API, allowing for combinations of various query results.
void	disconnect() Disconnect from the underlying provider, halting all comms
protected void	emit(IProvider.ProviderInterfaceEmitted type, java.lang.Object... args)
Hash	getGenesisHash() Contains the genesis Hash of the attached chain.
RuntimeVersion	getRuntimeVersion() Contains the version information for the current runtime.
Types.Signer	getSigner()
ApiBase.ApiType	getType() The type of this API instance, either ‘rxjs’ or ‘promise’
boolean	hasSubscriptions() true when subscriptions are supported
EventEmitter	on(IProvider.ProviderInterfaceEmitted type, EventEmitter.EventListener handler) Attach an eventemitter handler to listen to a specific event
protected abstract ApplyResult	onCall(Types.OnCallFunction method, java.util.List<java.lang.Object> params, boolean needCallback, IRpcFunction.SubscribeCallback callback)
EventEmitter	once(IProvider.ProviderInterfaceEmitted type, EventEmitter.EventListener handler) Attach an one-time eventemitter handler to listen to a specific event
Types.QueryableStorage<ApplyResult>	query() Contains all the chain state modules and their subsequent methods in the API.
Types.DecoratedRpc<ApplyResult>	rpc() Contains all the raw rpc sections and their subsequent methods in the API as defined by the jsonrpc interface definitions.
Metadata	runtimeMetadata() Yields the current attached runtime metadata.
void	setSigner(Types.Signer signer) Set an external signer which will be used to sign extrinsic when account passed in is not KeyringPair
Types.SubmittableExtrinsics	tx() Contains all the extrinsic modules and their subsequent methods in the API.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

KEEPALIVE_INTERVAL

public static final int KEEPALIVE_INTERVAL

See Also:

Constant Field Values

signer

public Types.Signer signer

An external signer which will be used to sign extrinsic when account passed in is not KeyringPair

rpcBase

public RpcCore rpcBase

decoratedRpc

protected Types.DecoratedRpc<ApplyResult> decoratedRpc

options

protected Types.ApiOptions options

genesisHash

public Hash genesisHash

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.

runtimeVersion

public RuntimeVersion runtimeVersion

Contains the version information for the current runtime.

Constructor Detail

ApiBase

public ApiBase(IProvider provider,
               ApiBase.ApiType apiType)

Create an instance of the class

Parameters:

provider - the Provider instance

apiType - the type of the API

Example

import org.polkadot.api.ApiBase;
ApiBase api = new ApiBase();
api.rpc().subscribeNewHead((header) => {
    System.out.println("new block ");
    System.out.println(header.blockNumber);
});

ApiBase

public ApiBase(Types.ApiOptions options,
               ApiBase.ApiType apiType)

Method Detail

decorateRpc

protected <ApplyResult> Types.DecoratedRpc<ApplyResult> decorateRpc(RpcCore rpcCore,
                                                                    Types.OnCallDefinition<ApplyResult> onCall)

emit

protected void emit(IProvider.ProviderInterfaceEmitted type,
                    java.lang.Object... args)

onCall

protected abstract ApplyResult onCall(Types.OnCallFunction method,
                                      java.util.List<java.lang.Object> params,
                                      boolean needCallback,
                                      IRpcFunction.SubscribeCallback callback)

derive

public Types.Derive<ApplyResult> derive()

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

Example

api.derive.chain.bestNumber((number) => {
    System.out.print("best number ");
    System.out.println(number);
});

Specified by:

derive in interface IApi<ApplyResult>

query

public Types.QueryableStorage<ApplyResult> query()

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) => {
    System.out.print("new balance ");
    System.out.println(balance);
});

Specified by:

query in interface IApi<ApplyResult>

rpc

public Types.DecoratedRpc<ApplyResult> rpc()

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) => {
    System.out.print("new header ");
    System.out.println(header);
});

Specified by:

rpc in interface IApi<ApplyResult>

tx

public Types.SubmittableExtrinsics tx()

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}) => {
    System.out.print("tx status ");
    System.out.println(status.asFinalized.toHex());
});

Specified by:

tx in interface IApi<ApplyResult>

getType

public ApiBase.ApiType getType()

The type of this API instance, either ‘rxjs’ or ‘promise’

Specified by:

getType in interface Types.ApiBaseInterface<ApplyResult>

on

public EventEmitter on(IProvider.ProviderInterfaceEmitted type,
                       EventEmitter.EventListener handler)

Attach an eventemitter handler to listen to a specific event

Specified by:

on in interface Types.ApiBaseInterface<ApplyResult>

Parameters:

type - The type of event to listen to. Available events are connected, disconnected, ready and error

handler - The callback to be called when the event fires. Depending on the event type, it could fire with additional arguments. Example

api.on('connected', () => {
    System.out.println("API has been connected to the endpoint");
});
api.on('disconnected', () => {
    System.out.println("API has been disconnected from the endpoint");
});

once

public EventEmitter once(IProvider.ProviderInterfaceEmitted type,
                         EventEmitter.EventListener handler)

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

Specified by:

once in interface Types.ApiBaseInterface<ApplyResult>

Parameters:

type - The type of event to listen to. Available events are connected, disconnected, ready and error

handler - The callback to be called when the event fires. Depending on the event type, it could fire with additional arguments. Example

api.once('connected', () => {
    System.out.println("API has been connected to the endpoint");
});
api.once('disconnected', () => {
    System.out.println("API has been disconnected from the endpoint");
});

getGenesisHash

public Hash getGenesisHash()

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.

Specified by:

getGenesisHash in interface IApi<ApplyResult>

getRuntimeVersion

public RuntimeVersion getRuntimeVersion()

Contains the version information for the current runtime.

Specified by:

getRuntimeVersion in interface IApi<ApplyResult>

getSigner

public Types.Signer getSigner()

Specified by:

getSigner in interface IApi<ApplyResult>

hasSubscriptions

public boolean hasSubscriptions()

true when subscriptions are supported

runtimeMetadata

public Metadata runtimeMetadata()

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

setSigner

public void setSigner(Types.Signer signer)

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

disconnect

public void disconnect()

Disconnect from the underlying provider, halting all comms