A solidity Loan smart contract built at the blockchain meetup in Lagos

MeetupLoan.sol

pragma solidity 0.6.1;

interface MoneyToken {
    function transferFrom(address _from, address _to, uint256 _value) external returns (bool success);
}

contract Loan {
    mapping(address => int256) public loanRegistry;
    address owner = 0xCA35b7d915458EF540aDe6068dFe2F44E8fa733c;
    /**
     * Note: this ngnt address is the mainnet address
     * So it would only target the actual account if on mainnet.
     * NGNT is an ERC20 standard token so you can deploy a similar token
     * on this network. See here for the specs: https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20.md
     */
    address ngntTokenAddress = 0x05BBeD16620B352A7F889E23E3Cf427D1D379FFE;
    
    function sendLoan(int256 amount, address recipientsAddress) external {
        // ensure we are not loaning negative value
        require(amount > 0, "Loaning negative value wrong");
        require(msg.sender == owner, "You are not owner");
        
        // if we have loaned recipient previously update the loanRegistry
        int256 currentValue = loanRegistry[recipientsAddress];
        loanRegistry[recipientsAddress] = currentValue + amount;
        
        // transfer actual money token
        MoneyToken ngntToken = MoneyToken(ngntTokenAddress);
        require(ngntToken.transferFrom(owner, recipientsAddress, uint256(amount)), "Failed to transfer loan to receipient");
    }
}

If you were sending ethereum as the token, then you don't need the MoneyToken (aka part-ERC20) interface, what you would need to is:

// transfer actual eth token
recipientsAddress.transfer(uint256(amount))

A updated more dynamic version of this can be found here: https://gist.github.com/perfectmak/d32bad707d0b0c2caee6f257f2368f70