design_pattern_desicions.md

Design Pattern usage

Self Destruction

Initiating a self destruction of the contract

function kill() public onlyOwnerandAdmin{
    selfdestruct(msg.sender);
}

- Circuit Breaker

If the owner initates the circuit breaker, buying items is disabled. This allows for the remaining funds to be withdrawn. But new buyers,can buy items.

User access

Specific functions can only be accesed by specific accounts.

Only the owner and admins can use functions with the "onlyOwnerandAdmin" keyword

modifier onlyOwnerandAdmin() {

    require((msg.sender == owner()) || (admins[msg.sender] == true));

    _;
}

Only a seller can use functions with the "onlySeller" keyword

modifier onlySeller(){
    require(sellerCheck(msg.sender)); 
    _;
}

sellerCheck function :

function sellerCheck(address sellerAddress) public view returns(bool) {
    uint256 _id = sellerIds[sellerAddress];
    return sellers[_id].isSeller;
}