app.js

var taskInput = document.getElementById("new-task"); //new-task
var addButton = document.getElementsByTagName("button")[0]; //first button
var incompleteTasksHolder = document.getElementById("incomplete-tasks"); //ul #incomplete-tasks
var completedTasksHolder = document.getElementById("completed-tasks"); //ul #completed-tasks
//Add a new task

//New Task List Item
var createNewTaskElement = function(taskString) {
	//create list item
	var listItem = document.createElement("li");

	//input (checkbox)
	var checkBox = document.createElement("input"); //checkbox
	//label
	var label = document.createElement("label");
	//input (text)
	var editInput = document.createElement("input"); //text
	//Create button.edit
	var editButton = document.createElement("button");
	//Create button.delete
	var deleteButton = document.createElement("button");
	
	checkBox.type = "checkbox";
	editInput.type = "text";

	editButton.innerText = "Edit";
	editButton.className = "edit";
	deleteButton.innerText = "Delete";
	deleteButton.className = "delete";

	label.innerText = taskString;

	listItem.appendChild(checkBox);
	listItem.appendChild(label);
	listItem.appendChild(editInput);
	listItem.appendChild(editButton);
	listItem.appendChild(deleteButton);
	
	return listItem;
};

var addTask = function() {
	console.log("Add task...")
	var listItem = createNewTaskElement(taskInput.value);
	//append listItem to incompleteTasksHolder
	incompleteTasksHolder.appendChild(listItem);
	bindTaskEvents(listItem, tasksCompleted);

	//clear input value after task is added
	taskInput.value = "";
};


//Edit an existing task
var editTask = function() {
	console.log("Edit task...");

	var listItem = this.parentNode;

	var editInput = listItem.querySelector("input[type=text]");
	var label = listItem.querySelector("label");
	var containsClass = listItem.classList.contains("editMode");

	if(containsClass) {
		label.innerText = editInput.value;
	} else {
		editInput.value = label.innerText;
	}
	//Toggle .editMode on the parent li	
	listItem.classList.toggle("editMode");
};


//Delete an existing task
var deleteTask = function() {
	console.log("Delete task....");

	var listItem = this.parentNode;
	var ul = listItem.parentNode;
	ul.removeChild(listItem);
};



//Mark a task as complete
var tasksCompleted = function() {
	console.log("complete task....")
	//Append the task li to the ul #completed-tasks
	var listItem = this.parentNode;
	completedTasksHolder.appendChild(listItem);
	bindTaskEvents(listItem, tasksIncomplete);
};

//Mark a task as incomplete
var tasksIncomplete = function() {
	console.log("Task incomplete...")
	//Append the task li to the ul #incomplete-tasks
	var listItem = this.parentNode;
	incompleteTasksHolder.appendChild(listItem);
	bindTaskEvents(listItem, tasksCompleted);
};

var bindTaskEvents = function(taskListItem, checkBoxEventHandler) {
	//Select li children
	var checkBox = taskListItem.querySelector("input[type=checkbox]");
	var editButton = taskListItem.querySelector("button.edit");
	var deleteButton = taskListItem.querySelector("button.delete");

	//Bind the editTask to edit button
	editButton.onclick = editTask;
	//Bind deleteTask to delete button	
	deleteButton.onclick = deleteTask;
	//Bind checkBoxEventHandler to checkbox	
	checkBox.onchange = checkBoxEventHandler;
};


addButton.onclick = addTask;


for (var i = 0; i < incompleteTasksHolder.children.length; i++) {
	bindTaskEvents(incompleteTasksHolder.children[i], tasksCompleted);
};

for (var i = 0; i < incompleteTasksHolder.children.length; i++) {
	bindTaskEvents(completedTasksHolder.children[i], tasksIncomplete);
}