contract

Documentation

Overview

Package contract provides functions to work with contracts.

Index

• func Destroy()
• func GetScript(c Contract) []byte
• func GetStorageContext(c Contract) storage.Context
• func IsPayable(c Contract) bool
• type Contract
  • func Create(script []byte, params []byte, returnType byte, properties byte, ...) Contract
  • func Migrate(script []byte, params []byte, returnType byte, properties byte, ...) Contract

Functions

func Destroy

func Destroy()

Destroy deletes calling contract (the one that calls Destroy) from the blockchain, so it's only possible to do that from the contract itself and not by any outside code. When contract is deleted all associated storage items are deleted too. This function uses `Neo.Contract.Destroy` syscall.

func GetScript

func GetScript(c Contract) []byte

GetScript returns the script of the given contract. It uses `Neo.Contract.GetScript` syscall.

func GetStorageContext

func GetStorageContext(c Contract) storage.Context

GetStorageContext returns storage context for the given contract. It only works for contracts created in this transaction (so you can't take a storage context for arbitrary contract). Refer to the `storage` package on how to use this context. This function uses `Neo.Contract.GetStorageContext` syscall.

func IsPayable

func IsPayable(c Contract) bool

IsPayable returns whether the given contract is payable (able to accept asset transfers to its address). It uses `Neo.Contract.IsPayable` syscall.

Types

type Contract

type Contract struct{}

Contract represents a Neo contract and is used in interop functions. It's an opaque data structure that you can manipulate with using functions from this package. It's similar in function to the Contract class in the Neo .net framework.

func Create

func Create(
	script []byte,
	params []byte,
	returnType byte,
	properties byte,
	name,
	version,
	author,
	email,
	description string) Contract

Create creates a new contract using a set of input parameters:

script      contract's bytecode (limited in length by 1M)
params      contract's input parameter types, one byte per parameter, see
            ParamType in the `smartcontract` package for value
            definitions. Maximum number of parameters: 252.
returnType  return value type, also a ParamType constant
properties  bit field with contract's permissions (storage, dynamic
            invoke, payable), see PropertyState in the `smartcontract`
            package
name        human-readable contract name (no longer than 252 bytes)
version     human-readable contract version (no longer than 252 bytes)
author      contract's author (no longer than 252 bytes)
email       contract's author/support e-mail (no longer than 252 bytes)
description human-readable contract description (no longer than 64K bytes)

It returns this new created Contract when successful (and fails transaction if not). It uses `Neo.Contract.Create` syscall.

func Migrate

func Migrate(
	script []byte,
	params []byte,
	returnType byte,
	properties byte,
	name,
	version,
	author,
	email,
	description string) Contract

Migrate migrates calling contract (that is the one that calls Migrate) to the new contract. Its parameters have exactly the same semantics as for Create. The old contract will be deleted by this call, if it has any storage associated it will be migrated to the new contract. New contract is returned. This function uses `Neo.Contract.Migrate` syscall.