Web3 Ethereum DAPP

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Technologies/Software used: Solidity, React, Hardhat, Alchemy, and Vite

• Personal Project
• Smart contract created with Solidity and deployed with Alchemy and Hardhat
• Gets user wallet information through browser
• Sends blockchain transactions using Ropsten Ethereum
• Utilizes Giphy API to find gifs for a transaction with a given keyword

This project was a ton of fun and was created using a youtube tutorial. I learned so much about how the blockchain functions and how to interact with a smart contract from my front-end. A major problem I ran into right at the end of my project is that I made a typo in my smart contract which caused my receiver address to be undefined, and I had already deployed it by the time I figured that out. This was a major issue because the smart contract acts as a backend server for decentralized applications and once its deployed its immutable meaning you can't simply re-upload your code. In order to fix any issues with a smart contract you have to re-upload your smart contract entirely and re-link the contract address and new ABI. Through fixing this error I also learned that its very expensive to make mistakes by having to deploy contracts again and luckily I used a test network with Ropsten ETH, otherwise i'd be spending $500+ dollars in mainnet ETHER if I chose to deploy my app on the main network.

Solidity Smart Contract

//SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;


contract Transactions {
	uint256 transactionCount;



	event Transfer(address from, address receiver, uint amount, string message, uint256 timestamp, string keyword);


	struct TransferStruct {
		//properties of the object
		address sender;
		address receiver;
		uint amount;
		string message;
		uint256 timestamp;
		string keyword;
	}


	TransferStruct[] transactions;


	function addToBlockchain(address payable receiver, uint amount, string memory message, string memory keyword) public{
		transactionCount += 1;
		//only adds our transaction to the array, doesn't actually make the transaction on the blockchain
		transactions.push(TransferStruct(msg.sender, receiver, amount, message, block.timestamp, keyword));

		//executes the transaction on the blockchain
		emit Transfer(msg.sender, receiver, amount, message, block.timestamp, keyword);
	}

	function getAllTransactions() public view returns (TransferStruct[] memory){
		return transactions;
	}

	function getTransactionCount() public view returns (uint256){
		return transactionCount;
	}
}