atA922Te

1pragma solidity ^0.4.18;
2
3////////////////////////  Voting.sol - 1  ////////////////////////////////////////////
4
5// written for Solidity version 0.4.18 and above that doesn't break functionality 
6contract Voting {
7
8    // an event that is called whenever a Candidate is added so the frontend could
9    // appropriately display the candidate with the right element id (it is used
10    // to vote for the candidate, since it is one of arguments for the function
11    //"vote")
12    event AddedCandidate(uint candidateID);
13    
14    // describes a Voter, which has an id and the ID of the candidate they voted for
15    address owner;
16    
17    function Voting() public {
18        owner=msg.sender; 
19    }
20    
21////////////////////////  Voting.sol - 2  ////////////////////////////////////////////
22    
23    modifier onlyOwner {
24        // describes a Candidate
25        require(msg.sender == owner);
26        _;
27    }
28    
29    struct Voter {
30        uint candidateIDVote; // this flag will help authorization of voter
31        bool hasVoted;  // this flag will help to keep track of 1 voter - 1 vote
32    }
33
34    // describes a Candidate
35    struct Candidate {
36        string name;
37        string party;
38        uint noOFVotes;
39        bool doesExist; // "bool doesExist" is to check if this Struct exists
40    }
41    
42    // This is so we can keep track of the candidates
43    
44////////////////////////  Voting.sol - 3  ////////////////////////////////////////////
45    
46    // These state variables are used keep track of the number of Candidates/Voters
47    // and used to as a way to index them
48    uint numCandidates; // declares a state variable - number Of Candidates
49    uint numVoters;
50    uint numOfVotes;
51    
52    // Think of these as a hash table, with the key as a uint and value of
53    // the struct Candidate/Voter. These mappings will be used in the majority
54    // of our transactions/calls
55    // These mappings will hold all the candidates and Voters respectively
56    mapping (uint => Candidate) candidates;
57    mapping (address => Voter) voters;
58    
59    
60    ////////////////////////  Voting.sol - 4  ////////////////////////////////////////////
61    
62    /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
63    *
64    These functions perform transactions, editing the mappings *
65    * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
66    
67    function addCandidate(string name, string party) onlyOwner public {
68        // candidateID is the return variable
69        uint candidateID = numCandidates++;
70        // Create new Candidate Struct with name and saves it to storage.
71        candidates[candidateID] = Candidate(name,party,0,true);
72        AddedCandidate(candidateID);
73    }
74    
75    ////////////////////////  Voting.sol - 5  ////////////////////////////////////////////
76    function vote(uint candidateID) public {
77        // checks if the struct exists for that candidate
78        require(!voters[msg.sender].hasVoted);// this statement is to check this voter is not already voted
79        if (candidates[candidateID].doesExist == true) {
80            voters[msg.sender] = Voter(candidateID, true);
81            candidates[candidateID].noOFVotes++;
82            numOfVotes++;
83            numVoters++;
84        }
85    }
86    
87    ////////////////////////  Voting.sol - 6  ////////////////////////////////////////////
88    /* * * * * * * * * * * * * * * * * * * * * * * * * *
89    *
90    Getter Functions, marked by the key word "view" *
91    * * * * * * * * * * * * * * * * * * * * * * * * * */
92    // finds the total amount of votes for a specific candidate by looping
93    //through voters
94    function totalVotes(uint candidateID) view public returns (uint) {
95        return candidates[candidateID].noOFVotes;
96    }
97    
98    ////////////////////////  Voting.sol - 7  ////////////////////////////////////////////
99    
100    function getNumOfCandidates() public view returns(uint) {
101        return numCandidates;
102    }
103    
104    function getNumOfVoters() public view returns(uint) {
105        return numVoters;
106    }
107    
108    // returns candidate information, including its ID, name, and party
109    function getCandidate(uint candidateID) public view returns(uint,string,string,uint)
110    {
111        return (candidateID,candidates[candidateID].name,candidates[candidateID].party,candidates[candidateID].noOFVotes);
112    } 
113    
114}