Basic Overview

This is a simple EVM compatible voting smart contract built using solidity. This contract is based on the famous 3_Ballot.sol contract that is provided by Remix IDE as an example. This contract basically implements different functions for every action that takes place in a Voting Ballot. Also, it is important to note that there were certain drawbacks in the Ballot.sol contract, that I targeted and duly fixed in my SimpleVoting.sol contract.

Key Features

So, as we know, a basic voting contract has the following functionalities:

• Creation of Voting Ballot: Where all the competing proposals and the Chairperson of the Ballot are set
• Give Right to Vote: Which can only be called by the Chairperson of the Voting Ballot.
• Vote: The most pivotal functionality possessed by a voting contract, can be called by any address with a right to vote.
• Delegate: A very interesting property that allows a voter to themselves abstain from voting and transfer that vote to another voter.
• Compute and display winning proposal: To compute and display the details of the winning proposal at the end of the voting process.

Improvements and Modifications

Apart from the above mentioned basic features, that are already implemented in Ballot.sol, the following are some additional features introduced by me in SimpleVoting.sol:

1. Use of openzepplin/contracts: This makes my contract safe, efficient and immune to future releases and changes to Solidity itself.

2. Additional getters and public variables: To better monitor the state of my contract.

3. Multiple events: These events are deployed whenever there is a change in the state of the contract and store these events on the blockchain for later use. They also come in handy later during UI integration.

4. Multiple modifiers: Using the same conditional require (...) statements in every function over and over seemed redundant, hence made the code DRY.

5. Modified I/O from bytes32 to string: This was done to improve the readabilty and UX while keeping the gas as low as possible. This was made possible by 2 internal functions:

   • stringToBytes32 (): To convert string to bytes32 value at input.
     

   • bytes32ToString (): To convert bytes32 to string value at output.
     
     

6. Added change chairperson functionality: Thought it would be nice to have this feature. Can only be called by the acting chairperson.

7. Added multiple winning proposals feature: One of the biggest drawbacks of the Ballot.sol contract is that it assumes that there will always be only one winning proposal in every voting session, which is not very practical. So, I added provision to check for, compute and return multiple winning proposals if necessary. The necessary code elements are listed below:

   • winningProposals []: An array to store the indices of all the winning proposals.
     

   • computeWinningProposals (): A public function to compute the and add the winning proposals' indices to the above array. Callable only by chairperson.
     

   • getWinningProposals (): Getter function to display all the winning proposal indices.
     

   • getWinnerNames (): Getter function to display winning proposal names as a string. Uses bytes32ToString ().
     
     

Contributing

1. Clone repo and create a new branch $ git checkout https://github.com/moonman369/Simple-Voting-Contract -b <name_of_new_branch>.
2. Make changes and test.
3. Submit Pull Request with a comprehensive description of changes and modifications.