Added basic contract and functions to call the network from browser

.gitignore

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+eth/node_modules

eth/Voting.js

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+const Web3 = require("web3");
+const fs = require("fs");
+
+const URL = "http://localhost:8545";
+const web3 = new Web3(new Web3.providers.HttpProvider(URL));
+
+// account obtained from the local testnet (ganache)
+var voter;
+web3.eth.getAccounts().then(acc => (voter = acc[0]));
+
+// ABI, and the bytecode to be deployed on the network
+const abi = JSON.parse(fs.readFileSync("Voting_sol_Voting.abi").toString());
+const bytecode = fs.readFileSync("Voting_sol_Voting.bin").toString();
+
+// Getting an instance of the contract
+const deployedContract = new web3.eth.Contract(abi);
+
+//The address of the deployed contract
+console.log(deployedContract.options.address)
+
+// to be called from the frontend to vote for a candidate
+const voteForCandidate = candidate => {
+  deployedContract.methods
+    .incrementVote(web3.utils.asciiToHex(candidate)) // converting from string to bytes32 format as per contract
+    .send({ from: voter })
+    .then(res => {
+      deployedContract.methods
+        .totalVotesSecured(web3.utils.asciiToHex(candidate))
+        .call()
+        .then(res1 => {
+          console.log(res1); // number of votes
+        });
+    });
+};

eth/Voting.sol

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+pragma solidity >= 0.4.0 < 0.6.0;
+
+contract Voting {
+
+    // list of candidates
+    bytes32[] public candidateList;
+
+    constructor(bytes32[] memory candidateNames) public{
+        candidateList = candidateNames;
+    }
+
+    // mapping for candidates to number of votes (bytes32 is used instead of string for less gas consumption)
+    mapping (bytes32 => uint256) public votesReceived;
+
+
+
+    // check if a candidate is valid or not
+    function IsCandidateValid(bytes32 candidate) view public returns (bool) {
+        for(uint i = 0; i < candidateList.length; i++) {
+            if(candidateList[i] == candidate) {
+                return true;
+            }
+        }
+
+        return false;
+    } 
+
+    // Add vote to the candidate
+    function incrementVote(bytes32 candidate) public {
+        require(IsCandidateValid(candidate));
+        votesReceived[candidate] += 1;
+    }
+
+    // get the number of votes
+    function totalVotesSecured(bytes32 candidate) view public returns (uint256) {
+        require(IsCandidateValid(candidate));
+        return votesReceived[candidate];
+    }
+}

eth/Voting_sol_Voting.abi

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+[{"constant":true,"inputs":[{"name":"candidate","type":"bytes32"}],"name":"totalVotesSecured","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"","type":"bytes32"}],"name":"votesReceived","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"candidate","type":"bytes32"}],"name":"IsCandidateValid","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"","type":"uint256"}],"name":"candidateList","outputs":[{"name":"","type":"bytes32"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"candidate","type":"bytes32"}],"name":"incrementVote","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"inputs":[{"name":"candidateNames","type":"bytes32[]"}],"payable":false,"stateMutability":"nonpayable","type":"constructor"}]

eth/Voting_sol_Voting.bin

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