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Created November 30, 2021 01:30
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// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;
import "hardhat/console.sol";
contract CoffeePortal {
uint256 totalCoffee;
address payable public owner;
* A little magic, Google what events are in Solidity!
event NewCoffee(
address indexed from,
uint256 timestamp,
string message,
string name
constructor() payable {
console.log("Yo! Smart Contract");
// user who is calling this function address
owner = payable(msg.sender);
* I created a struct here named Coffee.
* A struct is basically a custom datatype where we can customize what we want to hold inside it.
struct Coffee {
address giver; // The address of the user who buys me a coffee.
string message; // The message the user sent.
string name; // The name of the user who buys me a coffee.
uint256 timestamp; // The timestamp when the user buys me a coffee.
* I declare variable coffee that lets me store an array of structs.
* This is what lets me hold all the coffee anyone ever sends to me!
Coffee[] coffee;
* I added a function getAllCoffee which will return the struct array, coffee, to us.
* This will make it easy to retrieve the coffee from our website!
function getAllCoffee() public view returns (Coffee[] memory) {
return coffee;
// Get All coffee bought
function getTotalCoffee() public view returns (uint256) {
// Optional: Add this line if you want to see the contract print the value!
// We'll also print it over in run.js as well.
console.log("We have %d total coffee recieved ", totalCoffee);
return totalCoffee;
* You'll notice I changed the buyCoffee function a little here as well and
* now it requires a string called _message. This is the message our user
* sends us from the front end!
function buyCoffee(
string memory _message,
string memory _name,
uint256 _payAmount
) public payable {
uint256 cost = 0.001 ether;
require(_payAmount <= cost, "Insufficient Ether provided");
totalCoffee += 1;
console.log("%s has just sent a coffee!", msg.sender);
* This is where I actually store the coffee data in the array.
coffee.push(Coffee(msg.sender, _message, _name, block.timestamp));
(bool success, ) ={value: _payAmount}("");
require(success, "Failed to send money");
emit NewCoffee(msg.sender, block.timestamp, _message, _name);
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