bind

Documentation

Overview

Package bind generates Ethereum contract Go bindings.

Detailed usage document and tutorial available on the go-ethereum Wiki page: https://github.com/ethereum/go-ethereum/wiki/Native-DApps:-Go-bindings-to-Ethereum-contracts

Index

• Variables
• func Bind(types []string, abis []string, bytecodes []string, pkg string, lang Lang) (string, error)
• func WaitDeployed(ctx context.Context, b DeployBackend, tx *types.Transaction) (common.Address, error)
• func WaitMined(ctx context.Context, b DeployBackend, tx *types.Transaction) (*types.Receipt, error)
• type BoundContract
  • func DeployContract(opts *TransactOpts, abi abi.ABI, bytecode []byte, backend ContractBackend, ...) (common.Address, *types.Transaction, *BoundContract, error)
  • func NewBoundContract(address common.Address, abi abi.ABI, caller ContractCaller, ...) *BoundContract
  • func (c *BoundContract) Call(opts *CallOpts, result interface{}, method string, params ...interface{}) error
  • func (c *BoundContract) Transact(opts *TransactOpts, method string, params ...interface{}) (*types.Transaction, error)
  • func (c *BoundContract) Transfer(opts *TransactOpts) (*types.Transaction, error)
• type CallOpts
• type ContractBackend
• type ContractCaller
• type ContractTransactor
• type DeployBackend
• type Lang
• type PendingContractCaller
• type SignerFn
• type TransactOpts
  • func NewKeyedTransactor(key *ecdsa.PrivateKey) *TransactOpts
  • func NewTransactor(keyin io.Reader, passphrase string) (*TransactOpts, error)

Variables

var (
	// ErrNoCode is returned by call and transact operations for which the requested
	// recipient contract to operate on does not exist in the state db or does not
	// have any code associated with it (i.e. suicided).
	ErrNoCode = errors.New("no contract code at given address")

	// This error is raised when attempting to perform a pending state action
	// on a backend that doesn't implement PendingContractCaller.
	ErrNoPendingState = errors.New("backend does not support pending state")

	// This error is returned by WaitDeployed if contract creation leaves an
	// empty contract behind.
	ErrNoCodeAfterDeploy = errors.New("no contract code after deployment")
)

Functions

func Bind

func Bind(types []string, abis []string, bytecodes []string, pkg string, lang Lang) (string, error)

Bind generates a Go wrapper around a contract ABI. This wrapper isn't meant to be used as is in client code, but rather as an intermediate struct which enforces compile time type safety and naming convention opposed to having to manually maintain hard coded strings that break on runtime.

func WaitDeployed

func WaitDeployed(ctx context.Context, b DeployBackend, tx *types.Transaction) (common.Address, error)

WaitDeployed waits for a contract deployment transaction and returns the on-chain contract address when it is mined. It stops waiting when ctx is canceled.

func WaitMined

func WaitMined(ctx context.Context, b DeployBackend, tx *types.Transaction) (*types.Receipt, error)

WaitMined waits for tx to be mined on the blockchain. It stops waiting when the context is canceled.

Types

type BoundContract

type BoundContract struct {
	// contains filtered or unexported fields
}

BoundContract is the base wrapper object that reflects a contract on the Ethereum network. It contains a collection of methods that are used by the higher level contract bindings to operate.

func DeployContract

func DeployContract(opts *TransactOpts, abi abi.ABI, bytecode []byte, backend ContractBackend, params ...interface{}) (common.Address, *types.Transaction, *BoundContract, error)

DeployContract deploys a contract onto the Ethereum blockchain and binds the deployment address with a Go wrapper.

func NewBoundContract

func NewBoundContract(address common.Address, abi abi.ABI, caller ContractCaller, transactor ContractTransactor) *BoundContract

NewBoundContract creates a low level contract interface through which calls and transactions may be made through.

func (*BoundContract) Call

func (c *BoundContract) Call(opts *CallOpts, result interface{}, method string, params ...interface{}) error

Call invokes the (constant) contract method with params as input values and sets the output to result. The result type might be a single field for simple returns, a slice of interfaces for anonymous returns and a struct for named returns.

func (*BoundContract) Transact

func (c *BoundContract) Transact(opts *TransactOpts, method string, params ...interface{}) (*types.Transaction, error)

Transact invokes the (paid) contract method with params as input values.

func (*BoundContract) Transfer

func (c *BoundContract) Transfer(opts *TransactOpts) (*types.Transaction, error)

Transfer initiates a plain transaction to move funds to the contract, calling its default method if one is available.

type CallOpts

type CallOpts struct {
	Pending bool           // Whether to operate on the pending state or the last known one
	From    common.Address // Optional the sender address, otherwise the first account is used

	Context context.Context // Network context to support cancellation and timeouts (nil = no timeout)
}

CallOpts is the collection of options to fine tune a contract call request.

type ContractBackend

type ContractBackend interface {
	ContractCaller
	ContractTransactor
}

ContractBackend defines the methods needed to work with contracts on a read-write basis.

type ContractCaller

type ContractCaller interface {
	// CodeAt returns the code of the given account. This is needed to differentiate
	// between contract internal errors and the local chain being out of sync.
	CodeAt(ctx context.Context, contract common.Address, blockNumber *big.Int) ([]byte, error)
	// ContractCall executes an Ethereum contract call with the specified data as the
	// input.
	CallContract(ctx context.Context, call ethereum.CallMsg, blockNumber *big.Int) ([]byte, error)
}

ContractCaller defines the methods needed to allow operating with contract on a read only basis.

type ContractTransactor

type ContractTransactor interface {
	// PendingCodeAt returns the code of the given account in the pending state.
	PendingCodeAt(ctx context.Context, account common.Address) ([]byte, error)
	// PendingNonceAt retrieves the current pending nonce associated with an account.
	PendingNonceAt(ctx context.Context, account common.Address) (uint64, error)
	// SuggestGasPrice retrieves the currently suggested gas price to allow a timely
	// execution of a transaction.
	SuggestGasPrice(ctx context.Context) (*big.Int, error)
	// EstimateGas tries to estimate the gas needed to execute a specific
	// transaction based on the current pending state of the backend blockchain.
	// There is no guarantee that this is the true gas limit requirement as other
	// transactions may be added or removed by miners, but it should provide a basis
	// for setting a reasonable default.
	EstimateGas(ctx context.Context, call ethereum.CallMsg) (usedGas *big.Int, err error)
	// SendTransaction injects the transaction into the pending pool for execution.
	SendTransaction(ctx context.Context, tx *types.Transaction) error
}

ContractTransactor defines the methods needed to allow operating with contract on a write only basis. Beside the transacting method, the remainder are helpers used when the user does not provide some needed values, but rather leaves it up to the transactor to decide.

type DeployBackend

type DeployBackend interface {
	TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error)
	CodeAt(ctx context.Context, account common.Address, blockNumber *big.Int) ([]byte, error)
}

DeployBackend wraps the operations needed by WaitMined and WaitDeployed.

type Lang

type Lang int

Lang is a target programming language selector to generate bindings for.

const (
	LangGo Lang = iota
	LangJava
	LangObjC
)

type PendingContractCaller

type PendingContractCaller interface {
	// PendingCodeAt returns the code of the given account in the pending state.
	PendingCodeAt(ctx context.Context, contract common.Address) ([]byte, error)
	// PendingCallContract executes an Ethereum contract call against the pending state.
	PendingCallContract(ctx context.Context, call ethereum.CallMsg) ([]byte, error)
}

PendingContractCaller defines methods to perform contract calls on the pending state. Call will try to discover this interface when access to the pending state is requested. If the backend does not support the pending state, Call returns ErrNoPendingState.

type SignerFn

type SignerFn func(types.Signer, common.Address, *types.Transaction) (*types.Transaction, error)

SignerFn is a signer function callback when a contract requires a method to sign the transaction before submission.

type TransactOpts

type TransactOpts struct {
	From   common.Address // Ethereum account to send the transaction from
	Nonce  *big.Int       // Nonce to use for the transaction execution (nil = use pending state)
	Signer SignerFn       // Method to use for signing the transaction (mandatory)

	Value    *big.Int // Funds to transfer along along the transaction (nil = 0 = no funds)
	GasPrice *big.Int // Gas price to use for the transaction execution (nil = gas price oracle)
	GasLimit *big.Int // Gas limit to set for the transaction execution (nil = estimate + 10%)

	Context context.Context // Network context to support cancellation and timeouts (nil = no timeout)
}

TransactOpts is the collection of authorization data required to create a valid Ethereum transaction.

func NewKeyedTransactor

func NewKeyedTransactor(key *ecdsa.PrivateKey) *TransactOpts

NewKeyedTransactor is a utility method to easily create a transaction signer from a single private key.

func NewTransactor

func NewTransactor(keyin io.Reader, passphrase string) (*TransactOpts, error)

NewTransactor is a utility method to easily create a transaction signer from an encrypted json key stream and the associated passphrase.