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Providers

The provider is a key part of our system that contains the wallet and determines how transactions, known as extrinsics, are sent. Instead of using polkadot-js’s KeyringPair and ApiPromise, we use our own solution. This helps us overcome certain limitations and simplifies the evm_account_mapping process.

The SDK includes three providers for different use cases:

  • KeyringPairProvider: The provider on-top of polkadot-js KeyringPair class. It's the most common provider for the SDK.
  • UIKeyringProvider: The provider for polkadot-js compatible browser wallet extensions.
  • EvmAccountMappingProvider: The provider for MetaMask. It required the evm_account_mapping pallet to be enabled on the chain.

All provider implementations have following properties & methods.

address

string

The SS58 format address of the wallet.

name

string

The name of the provider implementation. You can use it to distinguish different providers.

The name for each provider implementation is:

  • KeyringPairProvider: keyring
  • UIKeyringPairProvider: uiKeyring
  • EvmAccountMappingProvider: evmAccountMapping
if (provider.name === 'keyring') {
  console.log('This is a KeyringPairProvider')
}

isCertificateExpired

boolean

Check if the certificate is expired.

const isExpired = provider.isCertificateExpired

hasCertificate

boolean

Check if the provider has a certificate.

const hasCertificate = provider.hasCertificate

send

Submit an extrinsic to the chain.

Usage

const apiPromise = client.api
const result = await provider.send(apiPromise.tx.system.remark('Hello, Phat'))

Parameters

extrinsic

SubmittableExtrinsic

Any SubmittableExtrinsic instance from @polkadot/api. It usually returns by api.tx.*.

transform (optional)

(input: ISubmittableResult) => ISubmittableResult

Set a customize transform function to the extrinsic result before returns.

It use internally and you don't need to use it in most cases.

Returns

SubmittableResult

The result of the extrinsic submission, check detailed on polkadot-js/api.

adjustStake

Adjust the staking token for any Phat Contract. The contract's share of the staking pool determines its portion of computational resources.

Usage

const contractId = '0x...'
await provider.adjustStake(contractId, 1e14)

Parameters

contractId

string

The contract id of the contract.

amount

number

The amount of stake to adjust. It can be a negative number to unstake specified amount of tokens.

signCertificate

Get the CertificateData from the provider. The CertificateData will cache for specified time as ttl parameter set.

Usage

const cert = await provider.signCertificate()

Parameters

ttl (optional)

number

The time to live of the certificate. It's in the unit of seconds. The default value is 0x7fffffff (2,147,483,647 seconds, or 68 years).

Returns

CertificateData

revokeCertificate

Revoke the certificate cache inside the provider.

Usage

provider.revokeCertificate()