Cyclic inter contract calling in smartpy

Question

What I am trying to achieve is that, once I receive data from another contract my contract should return data after computation to same contract who has sent the data.

Computational Contract

import smartpy as sp

class Try(sp.Contract):
    def __init__(self):
        self.init(mynum = sp.int(0))

    @sp.entry_point
    def addTwo(self,params):
        c = sp.contract(sp.TRecord(ans = sp.TInt),sp.source,entry_point="getit").open_some()

        mydata = sp.record(ans = params.num+2)
        sp.transfer(mydata,sp.mutez(0),c)

    @sp.entry_point
    def addThree(self,params):
        c = sp.contract(sp.TRecord(ans = sp.TInt),sp.source,entry_point="getit").open_some()

        mydata = sp.record(ans = params.num+3)
        sp.transfer(mydata,sp.mutez(0),c)

@sp.add_test(name="try")
def test():
    obj = Try()
    scenario = sp.test_scenario()
    scenario+=obj

Sender Contract / Data requester Contract

import smartpy as sp

class Try(sp.Contract):
    def __init__(self):
        self.init(mynum = sp.int(0))

    @sp.entry_point
    def sendit(self,params):
        c = sp.contract(sp.TRecord(num = sp.TInt),sp.address("KT19eXrMDTGARFMsAmByyFw5ZZTb783w8gDT"),entry_point="addTwo").open_some()
        mydata = sp.record(num = params.num)
        sp.transfer(mydata,sp.mutez(0),c)


    @sp.entry_point
    def getit(self,params):
        self.data.mynum = params.ans


@sp.add_test(name="test")
def test():
    obj = Try()
    scenario = sp.test_scenario()
    scenario += obj

It is giving following Error

Status: backtracked

(Error while parsing result)

Computational Contract Address - KT19eXrMDTGARFMsAmByyFw5ZZTb783w8gDT Sender Contract -KT1HiPv2wdsx9o1SZz9mMVfXREixWL11DHFw

Use smartpy explorer to access the contract

Answer 1

You need to use sp.sender and not sp.source (contrary to what we discussed earlier today) in the computational contract.