ERC20 metadata and ERC20Detailed

[abcoathup]

Hi @jaureguino,

@jaureguino

a) I do not “import” OpenZelpelin Contracts, as the documentation suggests but rather, I create all functions/contracts within my Solidity script;

To keep your system secure, you should always use the installed code as-is, and neither copy-paste it from online sources, nor modify it yourself.
https://docs.openzeppelin.com/contracts/3.x/#usage

I recommend importing OpenZeppelin Contracts rather than copying.

@jaureguino

b) I do not know much about OpenZeppelin 2.x nor 3.x nor I have ever used them;
– Question: Could you please shed some light on the difference between these two versions

OpenZeppelin Contracts 2.x supports Solidity 0.5
OpenZeppelin Contracts 3.x supports Solidity 0.6 and 0.7
OpenZeppelin Contracts 4.0 (currently release candidate) supports Solidity 0.8

For creating a token today I would look at using OpenZeppelin Contracts 4.0 when it is released (depending on your timeline).

There isn't a lot of complexity in your token, other than minting at certain stages and being pausable.

Depending on your use case, you could instead mint tokens into TokenTimelock (https://docs.openzeppelin.com/contracts/3.x/api/token/erc20#TokenTimelock) contracts if locking for a specific period of time. Though you should consider addressing: Bypassing Smart Contract Timelocks

@jaureguino

c) I could not find the ERC20Detailed function on https://github.com/OpenZeppelin/openzeppelin-contracts/tree/master/contracts/token/ERC20.
– Question: Am I looking at the wrong place?

Metadata was merged into ERC20 in OpenZeppelin Contracts 3.x

For 2.5.1 we can use the release tag:

OpenZeppelin/openzeppelin-contracts/blob/v2.5.1/contracts/token/ERC20/ERC20Detailed.sol

@jaureguino

d) I looked at https://docs.openzeppelin.com/contracts/2.x/api/token/erc20#ERC20Detailed but it was not easy for me how to reapply this function.
– Question: Do you have a working example somewhere where I to see it working?

Unless you need Solidity 0.5 you could be using a later version of OpenZeppelin Contracts and Solidity.

ERC20 - OpenZeppelin Docs