I am trying to create a Todo list and wonder how I would go about keeping the completed todos from vanishing each time I add a new task. I am aware that this is happening because I clear my div each time a new task is added, however I am unsure on how to proceed for me to keep using arrays on this and still show completed tasks along with new tasks.
Codepen: https://codepen.io/martinkariuki7-the-looper/pen/OJvQXRW
const newToDo = document.getElementById('todo-new')
const addBtn = document.getElementById('addToDo')
const main= document.getElementById('toDoList')
const taskDone = document.getElementsByClassName('task')
let toDoList = []
// populate to do list
function populateToDo(){
let todo = newToDo.value
todo !== null && todo !== '' ? toDoList.push(todo) : alert('You must write something')
updateDOM()
}
//Update DOM
function updateDOM(){
// Clear main div
main.innerHTML = `<h1>To do list </h1>`
// Show tasks on the front
toDoList.forEach(item =>{
let task = document.createElement('div')
task.classList.add('task')
task.innerHTML = `<label><input type="checkbox" >${item}</label><br>`
main.append(task)
task.addEventListener('change', () => task.classList.toggle('task-complete'))
newToDo.value = ''
})
}
// Event listeners
// Add Tasks
addBtn.addEventListener('click', populateToDo)
newToDo.addEventListener('keydown', (e) => {
if(e.code === 'Enter'){
e.preventDefault()
populateToDo()
}
})
If you want to use an array to update the list, you need to compare what you have with what will be changed.
If there aren't items with the same text, you could do something like this:
function updateNodes()
{
const nodesMap = new Map();
[...document.querySelectorAll('div label')]
.forEach(node => {
nodesMap.add(node.innerText, node);
});
const nodesUpdate = [];
toDoList.forEach(item => {
if (nodesMap.has(item)) {
nodesUpdate.push(nodesMap[item]);
} else {
const newNode = document.createElement('div');
newNode.classList.add('task');
newNode.innerHTML = `<label><input type="checkbox" >${item}</label>`;
nodesUpdate.push(newNode);
}
});
return nodesUpdate;
}
Otherwise, each item (or task) needs to have an identification. Otherwise, if there are two items with the same name, you won't know which one was removed or moved. Besides, without identifications, you can't know if an item was renamed.
The code here was not tested and, of course, you need to adapt it to your needs.