Can´t put name to new token

Support Contracts
1

I want to create a smart contract for minting NFTs in Open Sea, very basic. Anyway, I´m struggling.

I can´t put name to new token, I receive this error:

project:/contracts/AxolotolImperium.sol:17:32: TypeError: Wrong argument count for modifier invocation: 2 arguments given but expected 0.
constructor() internal ERC721 ("AxolotlImperium", "AXOL") {
^--------------------------------^

In other hand, how do I read the images in my server, assign its non fungible number and upload it to Open Sea?

:1234: Code to reproduce

    pragma solidity >=0.5.16 <0.9.0;

    import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
    import "@openzeppelin/contracts/ownership/Ownable.sol";

    contract AxolotolImperium is Ownable, ERC721 {

        struct Metadata {
            uint8 color;
            string tittle;
        }

        mapping (uint256 => Metadata) id_to_date;

        string private _currentBaseURI;

        constructor() internal ERC721 ("AxolotlImperium", "AXOL") {

        }

    }

:computer: Environment

Truffle

2

Hello @igdiaz

What version of Solidity are you using. When I try to compile your code in Remix. I get other errors:

  • import "@openzeppelin/contracts/ownership/Ownable.sol"; is not a valid path in current version of OZ contracts
  • internal constructor is also an old syntax. Solidity 0.8.0 uses the abstract contract syntax instead of constructor visibility.

I would recommend you update your compiler to 0.8.x and OZ to 4.4.0

1 Like
3

Hi Amxx,

Thanks, I´m using the next:

Truffle v5.4.22 (core: 5.4.22)
Solidity v0.5.16 (solc-js)
Node v14.17.1
Web3.js v1.5.3

I tried to unistall Truffle and Solidity, install again and it still being the same version, is that the latest? Or how do I install the 0.8.0?

4

Hi Amxx,

i just updated to Solidity 0.8.3 and OZ 4.4.0 upgradeable. I still can´t name the token, I have this error:

TypeError: Wrong argument count for modifier invocation: 2 arguments given but expected 0.
--> project:/contracts/AxolotlImperium.sol:17:23:
|
17 | constructor() ERC721Upgradeable ("AxolotlImperium", "AXOL") {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

My code is the next one:

pragma solidity >=0.4.22 <0.9.0;

import "@openzeppelin/contracts-upgradeable/token/ERC721/ERC721Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";

contract AxolotlImperium is OwnableUpgradeable, ERC721Upgradeable {
  struct Metadata {
            uint8 color;
            string tittle;
        }

        mapping (uint256 => Metadata) id_to_date;

        string private _currentBaseURI;

        constructor() ERC721Upgradeable ("AxolotlImperium", "AXOL") {
        }
}
5

The code you shared compiles. Double check you have the right dependencies installed.

6

Hi Frangio,

With dependencies, do you mean Truffle, Solidity, and OpenZeppelin? Or do I have to install something else?

7

I´m getting this:

TypeError: Wrong argument count for modifier invocation: 2 arguments given but expected 0.
--> project:/contracts/AxolotlImperium.sol:17:23:
|
17 | constructor() ERC721Upgradeable ("AxolotlImperium", "AXOL") {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

8

@igdiaz My bad, not sure how I got the code to compile before.

The error is that you're using upgradeable contracts but using the constructor. Upgradeable contracts don't have a constructor, they have initializer functions. You should read the docs about this, and also take a look at the code generated by Contracts Wizard when you select upgradeability.

9

Hi Frangio,

Thank you so much, I will check those docs.

10

Hi Frangio,

The solution was to erase the Open Zeppelin upgradeable folder and install the normal contracts:

npm install @openzeppelin/contracts

These are my current versions:

Truffle v5.4.22 (core: 5.4.22)
Solidity - 0.8.3 (solc-js)
Node v14.17.1
Web3.js v1.5.3

I´ll keep using the constructor as long as I didn´t understand the benefit of using the initializer with the upgradeable contracts.

Although, I´ll keep exploring the Contracts Wizard, looks very good.

Regards.

1 Like