conclient

README

go-conclient

Package conclient provides a basic smart-contract client for a smart-contract on a blockchain-network, for the Go programming language.

The blockchain-network could be Ethereum, some other EVM chain, or something else.

Documention

Online documentation, which includes examples, can be found at: http://godoc.org/github.com/reiver/go-conclient

Import

To import package conclient use import code like the follownig:

import "github.com/reiver/go-conclient"

Installation

To install package conclient do the following:

GOPROXY=direct go get https://github.com/reiver/go-conclient

Author

Package conclient was written by Charles Iliya Krempeaux

Documentation

Index

• type Client
  • func MakeClient(contract Contract, rpcurl string) Client
  • func (receiver Client) Call(methodname string, parameters ...interface{}) ([]interface{}, error)
  • func (receiver Client) Chain10Exponent() (uint64, bool)
  • func (receiver Client) ChainCode() string
  • func (receiver Client) ChainID() uint64
  • func (receiver Client) ChainName() string
  • func (receiver Client) ContractAddress() ethaddr.Address
  • func (receiver Client) CurrentBlockNumber() (*big.Int, error)
• type Contract

Types

type Client

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

Client is a client for a smart-contract on some blockchain-network.

To create a new conclient.Client, use conclient.Make. For example:

client := conclient.MakeClient(contract, rpcurl)

func MakeClient

func MakeClient(contract Contract, rpcurl string) Client

MakeClient makes a conclient.Client for contract 'Contract' using RPC-URL 'rpcurl'.

Example:

client := conclient.MakeClient(contract, rpcurl)

func (Client) Call

func (receiver Client) Call(methodname string, parameters ...interface{}) ([]interface{}, error)

Call calls the 'methodname' method on the contract, and returns the results.

func (Client) Chain10Exponent

func (receiver Client) Chain10Exponent() (uint64, bool)

Chain10Exponent returns the exponent of the blockchain-network this client is attached to.

The 'exponent' comes from the following equation that shows up the default-currency-code relates to the smallest-currency-code:

1 [DEFAULT-CURRENCY-CODE] = 10ⁿ [SMALLEST-CURRENCY-CODE]

(Where "n" is the value that Chain10Exponent returns.)

For example, on Ethereum:

1 ETH = 1,000,000,000,000,000,000 wei = 10¹⁸ wei

Therefore Chain10Exponent would return: 18

And also, for example, on Avalanche:

1 AVAX = 1,000,000,000 nanoAVAX = 10⁹ nanoAVAX

Therefore Chain10Exponent would return: 9

The reason this number is useful is this —

Often you will be working with numbers that aer in the smallest-currency of the blockchain-network. (Ex: "wei" rather than "ETH".) But you need to display things in the default-currency. (Ex: "ETH" rather than "wei".) So you need to do a conversion. (Ex: convert "wei" to "ETH".) The number Chain10Exponent returns will enable you to do that conversion.

For example:

var chainid uint64 = // ...

// ...

var wei *big.Int = // ...

// ...

var exponent *big.Int = new(big.Int).SetUint64( chain10.Exponent(chainid) )

var conversionDenominator *big.Int = new(big.Int).Exp(10, exponent)

var ethrat *big.Rat = new(big.Rat).SetFrac(wei, conversionDenominator)
var eth *big.Float = new(big.Float).SetRat(ethrat)

func (Client) ChainCode

func (receiver Client) ChainCode() string

ChainCode returns the (curency) chain-code of the blockchain-network this client is attached to.

See https://chainlist.org/ for the list of chain-ids mapped to (currency) chain-codes.

func (Client) ChainID

func (receiver Client) ChainID() uint64

ChainID returns the chain-id of the blockchain-network this client is attached to.

See https://chainlist.org/ for the list of chain-ids.

func (Client) ChainName

func (receiver Client) ChainName() string

ChainName returns the (human-legible) chain-name of the blockchain-network this client is attached to.

See https://chainlist.org/ for the list of chain-ids mapped to chain-names.

func (Client) ContractAddress

func (receiver Client) ContractAddress() ethaddr.Address

func (Client) CurrentBlockNumber

func (receiver Client) CurrentBlockNumber() (*big.Int, error)

CurrentBlockNumber returns the current (newest) block-number for the blockchain-network which this client is conencted to.

Each blockchain-network will (likely) have a different current (newest) blockchain-number.

And each blockchain-network's current (newest) block-number will change over time.

Example:

currentBlockNumber, err := client.CurrentBlockNumber()

type Contract

type Contract struct {
	ABI             abi.ABI
	Address         ethaddr.Address
	ChainID         uint64
	FromBlockNumber uint64
}

Contract represents a smart-contract (specified by its 'Address') on a particular blockchain-network (specified by its `ChainID`) which was created at a particular block-number (specified by 'FromBlockNumber').