How to Use Runtime API in Smart

<h1 align="center">How to Use Runtime API in Smart Contract</h1>
<p align="center" class="version">Version 0.1</p>

1. Introduction

For more details, you can view the API-doc and the source code here.

2. How to use Runtime API

Import package

from ontology.interop.System.Runtime import GetTime, CheckWitness, Log, Notify, Serialize, Deserialize
from ontology.interop.Ontology.Runtime import Base58ToAddress, AddressToBase58, GetCurrentBlockHash

Log: In smart contract, sending logs ( including socket notifications) to clients that are executing this smart contract

from ontology.interop.System.Runtime import GetTime, CheckWitness, Log, Notify, Serialize, Deserialize

def Main(operation):
    if operation == 'demo':
        return demo()
    return False


def demo():
    Log("hello world")

Notify: In smart contract, sending notifications (including socket notifications or rpc queries) to clients that are executing this smart contract

from ontology.interop.System.Runtime import GetTime, CheckWitness, Log, Notify, Serialize, Deserialize

def Main(operation):
    if operation == 'demo':
        return demo()
    return False


def demo():
    Notify("hello world")

GetTime: Return timestamp of the most recent block

from ontology.interop.System.Runtime import GetTime

def Main(operation):
    if operation == 'demo':
        return demo()
    return False


def demo():
    time=GetTime()
    return time # return a uint num

GetCurrentBlockHash: Return block hash of the most recent block

from ontology.interop.Ontology.Runtime import GetCurrentBlockHash

def Main(operation):
    if operation == 'demo':
        return demo()
    return False
    
def demo():
    block_hash = GetCurrentBlockHash()
    return block_hash

Serialize: Serialize the data from original type to byte array

Deserialize: Deserialize the data from byte array to original type

from ontology.interop.System.Runtime import GetTime, CheckWitness, Log, Notify, Serialize, Deserialize
from ontology.interop.System.Storage import Put, Get, GetContext

def Main(operation, args):
    if operation == 'serialize_to_bytearray':
        data = args[0]
        return serialize_to_bytearray(data)
    if operation == 'deserialize_from_bytearray':
        key = args[0]
        return deserialize_from_bytearray(key)
    return False


def serialize_to_bytearray(data):
    sc = GetContext()
    key = "1"
    byte_data = Serialize(data)
    Put(sc, key, byte_data)


def deserialize_from_bytearray(key):
    sc = GetContext()
    byte_data = Get(sc, key)
    data = Deserialize(byte_data)
    return data

Base58ToAddress: transfer a base58 address to address in form of byte array

AddressToBase58: transfer an address in form of byte array to a base58 address

from ontology.interop.System.Runtime import Log
from ontology.interop.Ontology.Runtime import Base58ToAddress, AddressToBase58

def Main(operation):
    if operation == 'demo':
        return demo()
    return False


def demo():
    base58_addr="AV1GLfVzw28vtK3d1kVGxv5xuWU59P6Sgn"
    addr=Base58ToAddress(base58_addr)
    Log(addr)
    base58_addr=AddressToBase58(addr)
    Log(base58_addr)

CheckWitness: Verify operational permissions of user or contract

from ontology.interop.System.Runtime import CheckWitness, Notify
from ontology.interop.Ontology.Runtime import Base58ToAddress
from ontology.builtins import bytearray

def Main(operation):
    if operation == 'demo':
        return demo()
    return False


def demo():
    addr=Base58ToAddress("AW8hN1KhHE3fLDoPAwrhtjD1P7vfad3v8z")
    res=CheckWitness(addr)
    Notify(res)
    return res