Here is my smart contract for a todo list.
Everything works, i've made a front-end to test it.
But, i'm trying to get real time updates when a task is removed, added or updated.
I know there are events for that, but how can i use them with a mapping data type?
Anyone could help me ?
Thanks !
// SPDX-License-Identifier: MIT
pragma solidity >=0.4.22 <0.9.0;
pragma experimental ABIEncoderV2;
contract ToDoList {
constructor() public {
addTask("Tache initiale");
}
struct Task {
uint256 id;
string description;
bool completed;
}
mapping(address => Task[]) public tasks;
function addTask(string memory _description) public {
uint256 id = uint256(
keccak256(abi.encodePacked(msg.sender, _description))
);
tasks[msg.sender].push(
Task({id: id, description: _description, completed: false})
);
}
function changeTaskStatus(uint256 _id, bool _status) public {
for (uint256 i = 0; i < tasks[msg.sender].length; i++) {
if (tasks[msg.sender][i].id == _id) {
tasks[msg.sender][i].completed = _status;
}
}
}
function removeTask(uint256 _id) public {
for (uint256 i = 0; i < tasks[msg.sender].length; i++) {
if (tasks[msg.sender][i].id == _id) {
delete tasks[msg.sender][i];
}
}
}
function getTasks() public view returns (Task[] memory) {
return tasks[msg.sender];
}
function tasksCount() public view returns (uint256) {
return tasks[msg.sender].length;
}
}You are not emitting any events.You should create appropiate events and emit them properly. For example:
// SPDX-License-Identifier: MIT
pragma solidity >=0.4.22 <0.9.0;
pragma experimental ABIEncoderV2;
contract ToDoList {
...
mapping(address => Task[]) public tasks;
event AddTask(address indexed creator, uint256 indexed id, string description);
function addTask(string memory _description) public {
uint256 id = uint256(
keccak256(abi.encodePacked(msg.sender, _description))
);
tasks[msg.sender].push(
Task({id: id, description: _description, completed: false})
);
emit AddTask(msg.sender,id,_description);
}
...
}