Initial commit

Author: AXC-Git

README.md

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+# Ballot Contract
+
+Demo smart contract to illustrate how voting may work on the blockchain
+
+## Process
+
+1. constructor
+2. addVoter()
+3. startVote()
+4. countVote()
+

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+/**
+ * @file ballot.sol
+ */
+
+pragma solidity ^0.5.0;
+
+contract Ballot {
+
+    struct vote{
+        address voterAddress;
+        bool choice;
+    }
+    
+    struct voter{
+        string voterName;
+        bool voted;
+    }
+
+    uint private countResult = 0;
+    uint public finalResult = 0;
+    uint public totalVoter = 0;
+    uint public totalVote = 0;
+    address public ballotOfficialAddress;      
+    string public ballotOfficialName;
+    string public proposal;
+    
+    mapping(uint => vote) private votes;
+    mapping(address => voter) public voterRegister;
+    
+    enum State { Created, Voting, Ended }
+	State public state;
+	
+	//creates a new ballot contract
+	constructor(
+        string memory _ballotOfficialName,
+        string memory _proposal) public {
+        ballotOfficialAddress = msg.sender;
+        ballotOfficialName = _ballotOfficialName;
+        proposal = _proposal;
+        
+        state = State.Created;
+    }
+    
+    
+	modifier condition(bool _condition) {
+		require(_condition);
+		_;
+	}
+
+	modifier onlyOfficial() {
+		require(msg.sender ==ballotOfficialAddress);
+		_;
+	}
+
+	modifier inState(State _state) {
+		require(state == _state);
+		_;
+	}
+
+    event voterAdded(address voter);
+    event voteStarted();
+    event voteEnded(uint finalResult);
+    event voteDone(address voter);
+    
+    //add voter
+    function addVoter(address _voterAddress, string memory _voterName)
+        public
+        inState(State.Created)
+        onlyOfficial
+    {
+        voter memory v;
+        v.voterName = _voterName;
+        v.voted = false;
+        voterRegister[_voterAddress] = v;
+        totalVoter++;
+        emit voterAdded(_voterAddress);
+    }
+
+    //declare voting starts now
+    function startVote()
+        public
+        inState(State.Created)
+        onlyOfficial
+    {
+        state = State.Voting;     
+        emit voteStarted();
+    }
+
+    //voters vote by indicating their choice (true/false)
+    function doVote(bool _choice)
+        public
+        inState(State.Voting)
+        returns (bool voted)
+    {
+        bool found = false;
+        
+        if (bytes(voterRegister[msg.sender].voterName).length != 0 
+        && !voterRegister[msg.sender].voted){
+            voterRegister[msg.sender].voted = true;
+            vote memory v;
+            v.voterAddress = msg.sender;
+            v.choice = _choice;
+            if (_choice){
+                countResult++; //counting on the go
+            }
+            votes[totalVote] = v;
+            totalVote++;
+            found = true;
+        }
+        emit voteDone(msg.sender);
+        return found;
+    }
+    
+    //end votes
+    function endVote()
+        public
+        inState(State.Voting)
+        onlyOfficial
+    {
+        state = State.Ended;
+        finalResult = countResult; //move result from private countResult to public finalResult
+        emit voteEnded(finalResult);
+    }
+}