Open Blockchain Workshop Series 1st edition

OBWS_1.md

Important addresses, links for the 1st Open Blockchain Workshop

Get some (testnet) ether here

István's account on Ropsten and the corresponding address: 0x22d491Bde2303f2f43325b2108D26f1eAbA1e32b

Use this Blockchain explorer: https://ropsten.etherscan.io

helloOBWS contract address: 0xD568eC979E970f104d429D7fEdc7aa78bD5Df8f6

pragma solidity ^0.4.24; pragma experimental ABIEncoderV2;

contract helloOBW { string public readME = "Hello Open Blockchain Workshop 2019.02.16";

event Message(string greeting, string message);
function hello(string _name) public {
    emit Message("Hi! how you doing?", _name);
}

}

István's rock paper scissors contract address: 0x34117bc3a7a453768039a085bb5dac6a51c3a397 RockPaperScissors code:

pragma solidity ^0.4.24; pragma experimental ABIEncoderV2;

//0 is rock //1 is paper //2 is scissors contract rockPaperScissors { address public player1; address public player2; uint256 choicePlayer1; uint256 choicePlayer2; bool alreadyCalled = false;

mapping(address => bool) tookHerMove;

constructor() public payable {
    require(msg.value == 0.01 ether);
    player1 = msg.sender;
}

function addPlayer2() public payable {
    require(!alreadyCalled);
    require(msg.value == 0.01 ether);
    player2= msg.sender;
    alreadyCalled = true;
}

function makeChoice(uint256 _choice) public {
    require(msg.sender == player1 || msg.sender == player2);
    require(_choice==0 ||_choice == 1||_choice==2);
    if(msg.sender==player1) {
        require(!tookHerMove[player1]);
        choicePlayer1 = _choice;
        tookHerMove[player1] = true;
    } else {
        require(!tookHerMove[player2]);
        choicePlayer2 == _choice;
        tookHerMove[player2] = true;
    }
    
}

event Draw(string message);
function withdrawPrize() public {
    require(tookHerMove[player1]&&tookHerMove[player2]);
    require(msg.sender==player1|| msg.sender == player2);
    uint256 winner = (3 + choicePlayer1 - choicePlayer2) % 3;
    if(winner==0) {
        emit Draw("It was draw");
    }
    if(winner == 1) {
        player1.transfer(this.balance);
    } else {
        player2.transfer(this.balance);
    }
    tookHerMove[player1] = false;
    tookHerMove[player2] = false;
}

}