Hello All,
I am trying to use the AEX-141 NFT standard for one of the projects that I am building.(here is the SC link from aeternity - aex141-examples/base_nft.aes at dev · aeternity/aex141-examples · GitHub).
My requirement is to interact with the deployed nft contract(whose address is passed in as a param) to my base contract and my base contract(a marketplace sortof) be controlling the nft’s ownership and other attributes.
But when I am making a intercontract contract call(my base contract to already deployed nft contract), I am getting an exception shown below.
Here is my base contract:
@compiler >= 6
include "String.aes"
include "Option.aes"
include "List.aes"
include "core/interfaces.aes"
payable contract SampleNFTInterContract =
function tokensTransferable(_token : NFT, _tokenId : int) : bool =
require(_token.is_approved_for_all(Call.caller, Contract.address) == true, "The HTLC contract must have been designated as an approved spender for the token")
true
public payable stateful entrypoint newContract(_tokenContract: NFT, _tokenId : int) : int =
tokensTransferable(_tokenContract, _tokenId)
What can be reason for this exception? How do I make the inter-contract call?
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The error means that you have contract A that calls contract B and then contract B calls back into contract A - this is not allowed in Sophia/FATE.
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Hi @hanssv.chain ,
in my contract B(NFT Contract), I am not making any other inter-contract calls.
My contract A from where I am trying to invoke B is the only inter-contract call and I am sure of it.
Given the situation, what do you think would be causing this?
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You asked what the error meant, and I explained that. I have not looked at your particular example and I have no insight there, sorry.
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Maybe @zkvonsnarkenstein.chain could help here as this is an AEX-141 contract?
I don’t think that this is a bug with the AEX-141 contract. @hanssv.chain already explained the cause of this error. The contracts seem to be calling each other and that’s not allowed. Since I only see a tiny snippet of the code, it’s not possible to determine where this happens exactly.
4 Likes
@Jkrish1011 that might indeed have been an issue with the initial state of the standard where this scenario has not been covered.
this is why transfer_to_contract entrypoint has been introduced, see AEXs/aex-141.md at master · aeternity/AEXs · GitHub
here a simple marketplace implementation that makes use of it:
just discovered this old thread and maybe the info is helpful to somebody out there 
2 Likes
@marco.chain Thanks for your input.
I will have a look at the latest AEX-141 standard do the necessary changes as needed.
thanks again!
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