script.js

// Todo list interactions and local storage.

const form = document.querySelector("form");
const input = document.querySelector("#txtTaskName");
const btnAddNewTask = document.querySelector("#btnAddNewTask");
const btnDeleteAll = document.querySelector("#btnDeleteAll");
const taskList = document.querySelector("#task-list");
let todos; 


loadItems();

eventListeners();

function eventListeners(){
    form.addEventListener("submit",addNewItem);
    taskList.addEventListener("click", deleteItem);
    btnDeleteAll.addEventListener("click", deleteAllItems);

}

//load items
function loadItems(){
    todos = getItemsFromLS();
    todos.forEach(function(item){
        createItem(item);
    })
}

function getItemsFromLS(){
     if(localStorage.getItem("todos")=== null){
        todos = [];
     }
     else{
        todos = JSON.parse(localStorage.getItem("todos"));
     }
     return todos;
}

function setItemToLS(newTodo){
    todos = getItemsFromLS();
    todos.push(newTodo);
    localStorage.setItem("todos", JSON.stringify(todos));
}


function createItem(newTodo){
    const li = document.createElement("li");
    li.className = "list-group-item list-group-item-secondary";
    li.appendChild(document.createTextNode(newTodo));

    const a = document.createElement("a");
    a.classList = "delete-item float-right";
    a.setAttribute("href","#");
    a.innerHTML='<i class="fas fa-times"></i>';

    li.appendChild(a);

    taskList.appendChild(li);
}


function addNewItem(e){
    if(input.value.trim() === ''){
        alert("Please enter a task.");
        e.preventDefault();
        return;
    }
    
          // create item
    createItem(input.value);

    setItemToLS(input.value);


    input.value = "";

    e.preventDefault();

}


function deleteItem(e){
        if(e.target.className === "fas fa-times"){
            if(confirm("Delete this task?")){
                e.target.parentElement.parentElement.remove();
                deleteTodoFromStorage(e.target.parentElement.parentElement.textContent);
            }
        }
    e.preventDefault();
}

function deleteTodoFromStorage(deletetodo){
    let todos = getItemsFromLS();

    todos.forEach(function(todo,index){
        if(todo === deletetodo){
            todos.splice(index, 1); // bulunduğu elementi silicek
        }
    });

    localStorage.setItem("todos", JSON.stringify(todos));
}





 
function deleteAllItems(e){
    if (confirm("Delete all tasks?")){
        while(taskList.firstChild){    // listede ilk eleman olduğu sürece eleman silicek liste boşaldığı zaman durucak
            taskList.removeChild(taskList.firstChild);
        }   

        localStorage.clear();
          
    } 
}